IntroductionDEFINITION OF BIOLOGY Biology is the study of living organisms. It is derived from Greek words.CLASSIFICATION OF LIVING ORGANIZATIONAccording to the modern classification given by R.H.Whittaker in 1969, living organisms are divided into five major kingdoms, which are:KINGDOM MONERAIt includes all prokaryotes, unicellular organisms. For example Bacteria and Cyan bacteria.KINGDOM PROTOCTISTA(PROTISTA)It includes unicellular Eukaryotic organisms, which are in between plants and animals. e.g. Chlamydomonas, Euglena, Paramecium. etc1. KINGDOM FUNGIIt includes non-chlorophyllus multi-cellular, thallophytic organisms having cell wall. For example all types of fungi, unicellular to multi-cellular like Mushrooms and Yeast etc.2. KINGDOM PLANTAEIt includes all chlorophyllus multi-cellular Eukaryotic living organisms having cellulose cell wall. For example apple, red wood etc.3. KINGDOM ANIMALIAIt includes all Eukaryotic multi-cellular, non-chlorophyllus organisms having no cell wall. For example Hydra, Earthworm, Human Beings etc.EUKARYOTIC ORGANISMSThose organisms, which have true membranous structure in their cells, like mitochondria, golgi bodies, endoplasmic reticulum. e.g. All plants, Higher animals.PROKARYOTESThose living organisms, which do not have true membranous structure in their cells. e.g. Bacteria, Blue green algae.PHYLETIC LINEAGEAll living organisms of today belong to a common ancestor and each specie of organism arranged no ancestor to descendent order with rest of the group evolved from one that immediately preceded.BRANCHES OF BIOLOGY1. MOLECULAR BIOLOGYIt is a recent branch of biological science that deals with the structure and function of the molecules that form structure of cell and organelles that take part in the biological processes of a living organism (Nucleic acid – Protein molecule)2. MICRO BIOLOGYIt deals with the study of micro-organisms (viruses, bacteria, protozoan etc)3. ENVIRONMENTAL BIOLOGYIt deals with the study of environment and its effect on organisms.4. MARINE BIOLOGYIt deals with the study of organisms inhabiting the sea an ocean, and the physical and chemical characteristics of their environment.5. FRESH WATER BIOLOGY

It deals with the life dwelling in fresh waters, physical and chemical characteristics of fresh water bodies affecting it.6. PARASITOLOGYIt deals with the study of parasitic organisms, their life cycles, mode of transmission and interaction with their hosts.7. HUMAN BIOLOGYThe branch of biology deals with all biological aspects of man regarding evolution, anatomy physiology, health, inheritance etc.8. SOCIAL BIOLOGYSocial biology is concerned with the social interactions with in a population of a given species, especially in human beings focuses on such issue as whether certain behavior are inherited or culturally induced.9. BIOTECHNOLOGYThis is a very recent branch introduce in biological sciences. It deals with the use of data and techniques of engineering and technology for the study and solution of problems concerning living organisms particularly the human beings.BIOLOGICAL METHODIn order to solve the biological problems (any animal or plant disease or environmental hazard), following steps are necessary.1. HYPOTHESISAn educated guess or fact regarding the biological problem.INDUCTIVE REASONINGIsolated facts to reach a general idea that explain the biological problem.DEDUCTIVE REASONINGAccurate experimentation, true conclusions or results regarding the biological problems.2. OBSERVATION/EXPERIMENTSThe given hypothesis is checked with the help of observation and experiments and then on the basis of it a theory or rule is established.3. THEORYIf observations and experiments come true then hypothesis is taken true, other wise it is rejected. Only on the basis of true hypothesis a theory is established.4. LAW/PRINCIPLEWhen theory is proved to be true under all tested circumstances then it is accepted as a law.MALARIA Malaria means disease cause by bad air. Actual Causative agent is plasmodium (Vector Female, Anopheles Mosquito) Leveran first discover plasmodium in human R.B.C. Ronald Ross discovered plasmodium in the stomach of female Anopheles Mosquito. Grassi discover the complete life cycle of Plasmodium in human being and mosquito.ANTIBIOTICSSubstances or chemicals, which are required in small quantity to inhibit the

growth of Microorganisms. The first antibiotic was penicillin discovered by Fleming. Other examples are: Erythocin, Rythocin, Gentamycin, Ampicillin etc.CHEMOTHERAPYTreatment with drug or chemical.RADIOTHERAPYTreatment with radiations, like α, β, γ or X-rays.HYDROPONICSIt is the science of terrestrial plants growing in aerated solutions (add CO2 under pressure, in any liquid also known as aerated water). This technique is also known as soil less or water culture.ADVANTAGES1. Control weeds and soil disease problems.2. Area required for cultivation is minimum.3. Can be applied on any part of the world.4. Main purpose is to fulfill the food requirements of rapidly increasing world population.CLONINGProduction of duplicate copies of genetic material, cells or entire multicellular living organisms, occurring naturally in plants or animals. Duplicate copies are known as clones.NATURAL CLONING Identical twin, triplet in humans. Asexual reproduction in plants and animal. Regeneration and wound healing. Growth of tumor cells or cancers.ARTIFICIAL CLONING Cloning of human cells such as liver cells, skin cells, blood cells are quite helpful to develop human organs in laboratories. There are also enormous advantages of cloning in the field of medicine and agriculture. Examples are vegetative reproduction of fruits and nuts by grafting. Artificial cloning is also used for treating disease, production of medically significant substances such as Insulin, growth hormones, interferon and anti-thrombin etc.LEVEL OF BIOLOGICAL ORGANIZATIONLife is built on chemical foundation and the life of all living organisms emerges on the level of cell. The foundation of cell is based on elements. Atoms of different elements unite to form molecules. Living organism usually form extremely large and complex molecules by living matter which is present in their bodies. The molecules of living organisms are mostly composed of carbon and provide building blocks of living matter. Mostly living matter of an organism is composed of organic molecules along with inorganic compounds (minerals) are also associated for e.g. Human blood. Simple organic molecules present in living organisms are sugar, glycerol and fatty acids, amino acids, purine and pyramidines. Similar types of cells form-tissues, similar tissues form organs, different organs coordinating with each other form system and

different systems combine to form a living organism.Cell → Tissues → organs → System → An IndividualBiological organization can be divided into the following levels:SUB-ATOMIC PARTICLES“Particles that make up an atom are called sub-atomic particles”.For e.g. electron, proton and Neutron.ATOM“The smallest particle of an element that retains the property of that element”.For example: Hydrogen, carbon and oxygen etc.MOLECULE“The combination of similar and different atoms are called molecules”.For example Hydrogen and oxygen combines to form water molecules.ORGANELLE“A structure with in a cell that performs a specific function”.For example: Mitochondria, chloroplast etc.CELL“The smallest structural and functional unit of life”.For example: A nerve cellTISSUE“A group of similar cells that performs a specific function”.For example: Nervous tissue.ORGAN“A structure with in an organism usually compose of several tissue types that forms a functional unit”.For example: The brainORGAN SYSTEM“Two or more organs working together in the execution of a specific bodily function”.For example: The nervous system.MULTICELLULAR ORGANISM“An individual living thing composed of many cells are called Multicellular organisms”.For example: Pronghom antelope.SPECIE“A group of very similar inter breeding organisms constitutes a species”.For example Herd of pronghom antelope.POPULATION“Members of same species inhabiting the same area are considered as population”.For example: Herd of pronghom antelope.COMMUNITY“Population of several species living and interacting in the same area form a community”.For example: Snake, antelope and hawk.ECO-SYSTEM“A community with its environment including land, water and atmosphere, constitute an eco-system”.

BIOSPHERE“The part of earth inhibited by living organisms, both living and non-living components.”

Biological MoleculesBIOCHEMISRTY Biochemistry is a branch of biology, which deals with the study of chemical components and chemical processes in living organisms.WATER (H2O)MAIN CHARACTERISTICS OF WATER Chemically it is “Dihydrogen oxide” It is the most abundant component in living cell. Its amount varies approximately from 70 to 90% and life activities occur in the cell due to the presence of water. It is a polar molecule, means that it has a very slightly negative end (the oxygen atom) and a very slightly positive end (the hydrogen atom). Due to its polarity, H2O molecules form hydrogen bonds.IMPORTANT BIOLOGICAL PROPERTIES OF WATER(1) BEST SOLVENT Water is an excellent solvent for polar substances, when ionic substances dissolved in water, dissociate into positive and negative ions. Non-ionic substances, having charged groups in their molecules, are dispersed in water. Because of solvent property of water, almost all reactions in cells occur in aqueous media.(2) HIGH HEAT CAPACITY Water has great ability of absorbing heat due to its high specific heat capacity. The specific heat capacity of water is the number of calories required to raise the temperature of 1g water through 1ºC. The thermal stability plays an important role in water based protoplasm of individual’s metabolic activities.(3) HIGH HEAT OF VAPORIZATION Liquid water requires higher amount of heat energy to change into vapours due to hydrogen bonding which holds the water molecules together.

It provides cooling effect to plants when water is transpired, or to animals when water is respired.(4) ACT AS AMPHOTERIC MOLECULE Water molecule acts both as acid and a base. As acid, it gives up electron to form H+ ion, while as a base, it gains electron to form OH ions. H2O ↔ H+ + OH- It acts as buffer and prevents changes in the pH of living body.(5) PROTECTION Water is an effective lubricant that provides protection against damage resulting from friction. It also forms a fluid cushion around organs that helps to protect them from trauma.(6) AS REAGENT /TURGIDITY Water acts as a reagent in many processes such as photosynthesis and hydrolysis reactions. It also provides turgidity to the cells.ORGANIC COMPOUNDSThose compounds containing carbon (other than carbonates) are called organic compounds. E.g: carbohydrates, Proteins, Lipids and Nucleic acid.INORGANIC COMPOUNDSThose compounds, which are without carbon, are called inorganic compounds. E.g: water, carbondioxide, acids , bases and salts.MACROMOLECULESHuge and highly organized molecules which form the structure and carry out the activities of cells are called “Macromolecules” Macromolecules can be divided into four major groups. Proteins Carbohydrates Lipids Nucleic acids.MONOMERSMacromolecules are composed of large number of low molecular weight building blocks or subunits called “Monomers” E.g: Amino-acids (Protein).CONDENSATIONThe process by which two monomers are joined is called “Condensation”.In this process two monomers join together when a hydroxyl(OH) group is removed from one monomer and a hydrogen (-H) is removed from other monomer.This type of condensation is called “Dehydration Synthesis” because water is removed (dehydration ) and a bond is made (synthesis).HYDROLYSISA process during which polymers are broken dawn into their subunits (monomers) by the addition of H2O called “Hydrolysis “. It is just reverse of the condensation.FUNCTIONAL GROUPS

These are particular group of atoms that behave as a unit and give organic molecules their physical, chemical properties and solubility in aqueous solution. E.g Methyl group (CH3-) Hydroxyl or Alcohol group (OH-) Carboxylic acid or Organic-acid group (COOH-) Amino or Amine group (NH2-) Carbonyl group (CO=) Sulfhydryl group (SH-)PROTEINSThese are the complex organic compounds having C, H,O and N as elements but sometimes they contain P and S also. Due the presence of N they are called “Nitrogenous Compounds” Proteins constitute more than 50% of dry weight of cell. They are present in all types of cells and in all parts of the cell.CHEMICAL COMPOSITION OF PROTEINSProteins are polymers of amino-acids and number of amino-acids varies from a few to 3000 or even more in different proteins.These amino-acids are linked together by specialized bond or linkage called “peptide linkage”Each proteins has a unique sequence of amino-acids that gives the unique properties to molecules.AMINO ACIDIt is the basic structural unit of proteins and all amino-acids have an “Amino group (NH2-) and a “Carboxyl group (COOH-)” attached to the same carbon atom, also known as “Alpha carbon”. The have the general formula as:1. A hydrogen atom.2. An amino (NH2) group.3. A carboxyl group (COOH)4. “Something else” this is the “R” group.R│H2N ─C ─ COOH(Amino group) │ (Carboxylic group)H“R” may be a “H” as in glycine, or CH3 as in alanine, or any other group. So amino acids mainly differ in the R-group.POLYPEPTIDESAmino Acids are linked together to from polypeptides of proteins. The amino group of one amino acids may react with the carboxyl group of another releasing a molecule of water. E.g: Glycine and analine may combine to form a dipeptiedePEPTIDE LINKAGE/ BONDThe linkage between the hydroxyle group of carboxyl group of one amino-acid and the hydrogen of amino-group of another amino-acid release H2O and C-N link to form a bond called “Peptide bond”.TYPES OF PROTEINS ON THE BASIS OF STRUCTURE

There are four basic structural levels of proteins.(A) PRIMARY STRUCTURE A polypeptide chain having a linear sequence of amino-acids. Disulphide (S-S) bond is other important characteristic of the primary protein.E.g: Insulin Polypeptide chain.B) SECONDARY STRUCTURE In this type polypeptide chain of amino-acids become spirally coiled. This coiling results in the formation of a rigid and tubular structure called “Helix”C) TERTIARY STRUCTURE Polypeptide chain bends and folds upon it self forming a globular shape. It is maintained by three types of bonds. Namely ionic, hydrogen and disulfide (S-S).(D) QUATERNARY STRUCTURE This type is usually present in highly complex proteins in which polypeptide tertiary chains are aggregated and held together by hydrophobic interactions, hydrogen and ionic bonds.E.g: Haemoglobin molecule.FUNCTIONS OF PROTEIN They Build many Structures of the cell E.G: Plasma Membrane. All enzymes are proteins and in this way they control the whole metabolism of the cell. Skin, nails, hair, feather, horn etc. contain portion called keratin. Casein is the milk portion and ovalbumin is the egg white protein. Collagen present in bones, cartilage, etc. is the most abundant protein in higher vertebrates. Protein acts as antibodies, antigens and fibrin etc.CARBOHYDRATESIt is a group of organic compounds having carbon, oxygen and hydrogen, in which hydrogen and oxygen are mostly found in the same ratio as in water i.e. 2:1 and thus called “Hydrated carbons” They are found about 1% by weight and generally called Sugars or saccharides” due to their sweet taste except polysaccharides.CLASSIFICATION OF CARBOHYDRATESThe carbohydrates can be classified into following groups on the basis of number of monomers.1. Monosaccharide2. Oligosaccharides3. Polysaccharides.(1) MONOSACCHARIDES These are called “Simple Sugars”, because they can not be hydrolysed further into simple sugars. Their general formula is “Cn H2n On

They are white crystalline solids with sweet taste and soluble in water. They are present in various fruits and vegetables.E.g: Glucose, Galactose, Fructose and Ribose etc. Monosaccharide can be sub-classified according to umber of carbon atom present in each molecule. They may be triose, (Glycerose), tetrose (erythrose), pentose, (ribose), hexone (glucose) or heptose (Glucoheptose) having 3,4,5 ,6 and 7 carbon atoms respectively.(2) OLIGOSACCHARIDES These carbohydrates yield 2to 10 monosaccharides mnolecules on hydrolysis Disaccharides are the most common and abundant carbohydrates of oligosaccharides. These sugars are comparatively less sweet in taste, and less soluble in water.E.g: Maltose, Sucrose and lactose etc.(3) POLYSACCHARIDES These are the most complex and most abundant carbohydrates in nature. They are of high molecular weight carbohydrate which on hydrolysis yield mainly monosaccarides or products related to monosaccharide. These sugars are formed by the condensation of hundreds of thousands of monosaccharide units. They are tasteless and only sparingly souble in H2O.E.g: Strach, cellulose Glycogen , Dextrin Agar, pectin and Chitin etc.FUNCTIONS OF CARBOHYDRATES Carbohydrates are the potential source of energy. They act as storage food molecules and also work as an excellent building, protective and supporting structure. They also form complex conjugated molecules. They are needed to synthesize lubricants and are also needed to prepare the nectar in some flowers.LIPIDSThese are naturally occurring compounds, which are insoluble in water but soluble in organic solvents. They contain carbon, hydrogen and oxygen like carbohydrates rate but in much lesser ratio of oxygen than carbohydrates. These biomolecules are widely distributed among plants and animals.CLASSIFICATION OF LIPIDSFollowing are the important groups of lipids.1. Acylglycerol (fats and oil)2. Waxes3. Phospholipids.4. Terpenoids.(1) ACYLGLYCEROL (FATS AND OIL) These are found in animals and plants, provide energy for different metabolic activates and are very rich in chemical energy.

They are composed of glycerol and fatty acids. The most widely spread acylglycerol is triacyl glycerol, also called triglycerides or natural lipids.There are two types of acylgycerol(A) SATURATED ACYLGLYCEROL They contain no double bond. They melt at higher temperature than unsatured acylglycerols. Lipids containing saturated acylgycerol are solid and known as Saturated lipids.E.g: Butter and Animal fat. etc.(B) UNSATURATED ACYLGLYCEROL They contain unsaturated fatty acids i.e they contain one or more than one double bond between carbon atom(C=C-). They are liquid at ordinary temperature . They are found in plant also called “Oil”E.g: linolin found in cotton seeds etc.(2) WAXES Chemically waxes are mixtures of long chain alkanes and alcohols. Ketones and esters of long chain fathy acids Waxes are widespread as protective coatings of fruits and leaves some insects also secrete wax. Waxes protect plants form water loss and abrasive damage. They also provide water barrier for insects, birds and animals etc.(3) PHOSPHOLIPIDS It is most important class of lipids from biological point of view and is similar to riacylglycerol or an oil except that one fatty acid is replaced by phosphate group. The molecule of phospholipids consist of two ends, which are called hydrophilic (water loving end (head) and hydrophobic (water fearing)end (Tail). These are frequently associated with membranes and are related to vital functions such as regulation of cell permeability and transport process.(4) TERPENOIDS It is large and important class of lipids containing “Isoprenoid “ unit (C5H8). They help in oxidation reduction process, act as components of essential oils of plants and also found in cell membrances as “cholesterolSUB-CLASSES OF LIPIDS1. Terpenes2. Steroids.3. Carotenoids.(1) TERPENES This group based only on “Isoprenoid” unit and they are usually volatile in nature produce special fragrance. Derivatives of this group are found in vitamin A and are also important constituents of chlorophyll and cholesterol biosynthesis.

They are utilized in synthesis of “Rubber” and “Latex”, and some of these are used in perfumes.(2) STEROIDS This group of Terpenoids contains 17 carbon atoms ring called “steroid nucleus”.(3) CAROTENOIDS They consist of fatty acid like carbon chain and usually found in plants, for example carotene, xanthophylls etc.NUCLEIC ACIDSNucleic Acids Were First Isolated In 1870 By an Austrian Physician Fridrich Micscher from the nuclei of pus cells. These bio molecules are acidic in nature and present in the nucleus.TYPES OF NUCLEIC ACIDSNucleic acids are of two types.1. Deoxyribonucleic acid or DNA2. Ribonucleic acid or RNACHEMICAL NATURE OF NUCLEIC ACIDNucleic acids are complex substances. They are polymers of units called nucleotides. DNA is made up of deoxyribonucleotides, while RNA is composed of ribo nucleotides.STRUCTURE OF NUCLEOTIDEEach nucleotide is made of three subunitsa) 5-carbon monosaccharide (a pentose sugar)b) Nitrogen containing base.c) Phosphoric acid.(A) PENTOSE SUGARPentose sugar in RNA is ribose, while in DNA it is deoxyribose.(B) NITROGENOUS BASENitrogenous bases are of two types(I) PYRIMIDINES (SINGLE RINGED): These are cytosine (abbreviated as C), thymine (abbreviated as T), and uracil (abbreviated as U).(II) PURINES (DOUBLE RINGED): These are adenine (abbreviated as A) and guanine(abbreviated as G).C) PHOSPHORIC ACIDPhosphoric acid (H3PO4) has the ability to develop ester linkage with OH group of pentose sugar.FORMATION OF NUCLEOTIDEFormation of nucleotide takes place in two steps. First the mitrogenous base combines with pentose sugar at its first carbon to form a “Nucleoside”. In second step the phosphoric acid combines with the 5th carbon of pentose sugar to form a “Nucleotide”.(A) MONONUCLEOTIDES They exist singly in the cell or as a part of other molecules. These are not the part of DNA or RNA and some of these have extra phosphate groups e.g ATP.B) DINCULEOTIDES

These nucleotides are covalently bounded together and usually act as co-enzymesE.g NAD (Nicotinamide dinucleotide ).(C) POLYNUCLEOTIDES Nucleotides are found in the nucleic acid as “Polynucleotide” and they have a variety of role in living organisms. They usually perform the function of transmitters of genetic information.CONJUGATED MOLECULES Two different molecules, belonging to different categories, usually combine together to form “Conjugated molecules”. These conjugated molecules are not only of structural, but also are of functional significance. They play an important role in regulation of gene expression.(A) GLYCOPROTEIN AND GLYCOLIPIDSCarbolydrates may combine with proteins to form glycoprotein or with lipids to form glycolipid.FUNCTIONSa) Most of cellular secretions are glycoprotein’s in nature.b)Both glycoproteins and glycolipids are integral structural components of plasma membranes.(B) LIPOPROTEINSCombination of lipids and proteins form lipoproteins.FUNCTIONThey are basic structural framework of all types of membranes in the cells.(C) NUCLEOPROTEINSNucleic acids have special affinity for basic proteins . they are combined together to form nucleoproteins.FUNCTIONSThe nucleoproteins (Histone) are present in chromosomes.THINGS TO BE REMEMBER Proteins-Berzelius and G.J murlder. Lipids-Bloor in 1943. DNA –Hereditary material. RNA- carrier of genetic information. rRNA – (Ribosomal RNA)- Double stranded. Transcription- Formation of mRNA. Translation –Formation of Proteins by ribosmes.

EnzymesENZYMES(BIO-CATALYSTS) Enzymes are bio-catalyst which speed up the chemical reactions by lowering “Energy of activation”.ENERGY OF ACTIVATIONAmount of energy which is required to start a chemical reaction. OR Energy required to break a (particular covalent) bond present in reactant.NOMENCLATURE OF ENZYMESEnzyme is a Greek word means-En(in) and Zyme(yeast).DISCOVERY OF ENZYMETerm “Enzyme” was coined by F.W Kuhne in 1978.NATURE OF ENZYMEAlmost all enzymes are protein in nature except few which are nitrogenous acids like RNA-DNA(Ribozymes). Ribozymes catalyze reactions in genetic informations.CHARACTERISTICS OF ENZYMES Protein in nature and are formed by living cells. May be intracellular or extra cellular. Remains unchanged during and after the reaction. Speed up the rate of reaction by decreasing energy of action. Specific in their nature. Heat sensitive and act on particular (optimum) temp. Each has specific substrate pH for its activity. Action can be alter by activators and inhibitors.CLASSIFICATION OF ENZYME (ON THE BASIS OF STRUCTURE)Pure or Simple Enzyme consist of only protein (e.g.Amylase and Pepsin) Conjugated or Holoenzymes: May contain a non-protein part “Prosthetic group” as well (e.g. Phosphatase and Peptidase)Holoenzyme = Apoenzyme + Prosthetic group…………….(Protein part)….(Non-protein part)CLASSIFICATION OF ENZYME (ON THE BASIS OF FUNCTIONS)(1) OXIDOREDUCTASECatalyze reactions in which one substrate is oxidized while other is reduced. Sub classes are: Dehydrogenases(convert single bond to double bond) Oxidases (use oxygen as oxidant) Peroxidases (use H202 as oxidant) Hydroxylases (introduce hydroxyl group) Oxygenases (introduce mol. Oxygen in place of double bond).(2) TRANSFERASESTransfer one carbon group (e.g. methyl) from one substrate to another substrate.(3) HYDROLASESCatalyze hydrolytic cleavage of C-O, C-N, C-C and P-O bonds and other single bonds (e.g. Peptidases, Esterases, Glycosidases and Phosphatidases).

(4) LYASESCatalyze Elimination reactions to form double bond and reversible reaction by adding groups across double bond (e.g. Decarboxlases, Aldolases and Dehydratases).(5) ISOMERASESThey alter the structure but not the atomic composition by moving a group from one position to another in one molecule (e.g. Epimerases, Mutases).(6) LIGASESCatalyze reaction in which two molecules are joined. They are also known as synthtases.ROLE OF ENZYMEThe enzyme react with (energy rich or energy poor) molecules and forms an intermediate complex that breaks into,(a) Product(b) Enzyme(i) Substrate + Enzyme = Complex(ii) Complex = Product + EnzymeThe equilibrium is achieved if the ratio of conc of reactants (substrate) and product remains same.Rate of reaction 1/µ Energy of activationMODE OF ACTION OF ENZYMES1- The action of enzyme depends on its chemical structure. A typical enzyme molecule, has “3D” structure.2- Has depression or pit for substrate (to fit in) known as “Active site”.3- Any other site other than active site is called “Allosteric site”There are two theories in respect of enzyme action, which are as follows.LOCK AND KEY MODELProposed by Fischer (1898) and modified by Paul Filder and D.D Woods according to this model, The active site of enzyme has distinct shape. It allows few substrate to fit in (like a particular lock allows particular key to fit in) Enzyme breaks substrate to productFIGURE From Text Book 3.3 page #46 (The cycle of Enzyme – substrate Interaction)INDUCE FIT MODELProposed by koshland (1959), it states that Enzyme binds with a substrate This binding induce changes in enzyme structure Due to this change enzyme acts and forms productFACTORS AFFECTING ENZYME ACTIVITYThe activity of enzymes depend on following factors,1. SUBSTRATE CONCENTRATION Increases with increase in substrate concentration (up to a limit)

At very high concentration, activity again decreases due to saturation of enzyme with substrate and saturation of product i.e. higher concentration of product.2. TEMPERATURE Increases with in temperature(up to limits) Maximum activity at optimum temperature. Highly active at 37˚C and destroyed at 100˚C At 0˚C minimum activity.3. PHEnzymes are pH specific i.e. work in specific pH(because of protein can act both in acidic and basic medium.4. WATEREnzyme activity is usually maximum (up to limits) but decrease after limits (dilution of enzyme)5. RADIATIONSEnzymes become inactive due to radiations (including Alpha, Beta, Gamma rays).6. CO-ENZYME AND ACTIVATORSInduce the enzyme activity.THINGS TO BE REMEMBERINHIBITORSSubstances which decreases the activity of enzymes.COMPETITIVE INHIBITORSInhibitor molecules which resemble the normal substrate molecule and compete for admission into the active site. They block the substrate from entering active site.NON-COMPETITIVE INHIBITORSInhibitors bind to a part of the enzymes away from the active site (Allosteric site). This binding cause change in the enzyme molecule shape and decrease in enzyme activity.FEED BACK INHIBITIONCommon biological control mechanism of brain in order to regulate enzyme activity.PROSTHETIC GROUPNon-protein part of enzyme (Co-enzyme or Co-factor)CO-ENZYMEWhen prosthetic group consist of organic molecules (like FAD/NAD)CO-FACTORS/ACTIVATORSWhen prosthetic group consist of inorganic molecules (like Ca++, Na+ etc).APOENZYMEProtein part of enzyme.

The CellCELL It is the basic structural and functional unit of life, which is able to carry out all the life processes.CELL THEORYThe cell theory was collectively proposed by “Schleiden(1838), Schawnn(1839) and Virchow (1858).IMPORTANT POSTULATESThe fundamental points of the cell theory are:(a) The cell is the structural and functional unit of all living organism.(b) All organisms are composed of one or more cells.(c) New cells can arise only by division of pre-existing cells.Thus cell theory established the concept that the function of an organism is the result of activities and interaction of the cell units.MICROSCOPEDEFINITIONAn instrument with the help of which we see small, tiny and minute objects which can’t be observe by naked human eye.TYPES OF MICROSCOPEThere are three main types of microscope.1. LIGHT MICRO SCOPEIn this microscope visible light is used as source of illumination.2. X-RAY MICROSCOPEX-Rays are used as source of illumination.3. ELECTRON MICROSCOPEElectron beam is used as source of illumination.There are further two sub-types of electron microscope which are:(A)TRANSMISSION ELECTRON MICROSCOPEIn this type resultant image is obtained on a fluorescent screen or photographic film.(B)SCANNING ELECTRON MICROSCOPEIn this type resultant image is obtained on a television screen.MAGNIFICATION OF MICROSCOPEAbility of microscope to increase the shape and size of the objects image. It can be calculated by multiplying the power of its eye pieces with its magnifying power of its objective.RESOLUTION OF MICROSCOPEThe capacity of microscope to separate adjacent forms or object. Also known as “Minimum Resolved Distance”.CONTRASTIt is important to distinguishing one part of cell from another.(Difference between light and electron microscope – From Text page #57)Prokaryotes and eukaryotes – From Text page #58)CELL MEMBRANEEach cell is covered by an asymmetrical, porous, thin, semi permeable sheet

called cell membrane or plasmalemma.CHARACTERISTICS OF CELL MEMBRANELiving part of the cell, consist of lipid + protein. 1.5 micron in thickness. Consist of two layers of lipid. Lipid of plasma membrane are,1. Phospho-lipids2. Glycolipids3. Sterol4. Cholesterol.STRUCTURE OF CELL MEMBRANECell membrane made up of phospho-lipids bilayer and each layer consists of ,1. Head (hydrophilic end)2. Tail (hydrophobic end)1. HEAD (HYDROPHILIC/POLAR END)Present towards the surface and formed of phosphates.2. TAIL (HYDROPHOBIC/NON-POLAR END)Present towards the center and formed of fatty acids.The non-polar ends of phospho lipids face each other, whereas their polar ends are in association with protein or carbohydrates between every two phospo lipids molecule lies a molecule of “Cholesterol”.FLUID MOSAIC MODELINTRODUCTIONThe fluid mosaic, bilayer model was proposed by “Singer and Nicolson (1972).POSTULATES OF FLUID MOSAIC MODELImportant postulates of this model are,(a) The cell membrane consists of lipid bilayer, in which a variety of proteins are present.(b) These proteins float in the fluid matrix of lipid (as ice bergs in the sea)(FIGURE 4.4 Page #61)ARRANGEMENT OF PROTEINSAccording to the fluid mosaic model proteins are:1. INTRINSIC/INTEGRAL PROTEINSThese proteins peneterate the membrane surface and enter the lipid layers (partially or wholly)2. EXTRINSIC/PERIPHERAL PROTEINSThese are located adjacent to outer and inner surface of membrane and float like ice-berg in the sea.ARRANGEMENT OF LIPIDSThe non-polar end face each other while their polar ends are towards the surface.SIGNIFICANCE OF MODEL Cell membrane is flexible. Can change shape (because the protein and lipid of the membrane can move).FUNCTION OF MEMBRANE PROTEIN Certain proteins themselves act as enzymes.

Some protein act as carrier for active transport. Provide elasticity to membrane. Pores are lined by the proteins.FUNCTION OF LIPIDS PRESENT IN MEMBRANE The lipids give rigidity to cell membrane. They lower the surface tension.FUNCTIONS OF CELL MEMBRANE It performs the two main function. Protection of Protoplasm. Regulation of material (In and Out of cell) through its permeabality.PERMEABILITY OF MEMBRANEThe permeability of membrane is regulated by two processes.(1) Passive Transport (Osmosis and Diffusion)(2) Active Transport (Endocytosis, Exocytosis)1. PASSIVE TRANSPORTSuch type of molecules transport which does not require energy. It is further divided into,DIFFUSIONSpreading and free movement of molecules (or ions) from the region of higher concentration to the region of lower concentration (till equilibrium state)SIGNIFICANCE Movement of oxygen and digested food (glucose, amino acids, fatty acids) into the cell. Movement of excretory waste out of cell.OSMOSISDiffusion of water by semipermeable membrane or the movement of solvent molecules from higher to lower concentration across semi permeable membrane.SIGNIFICANCE Liquids, primarily water molecules enter and leave the cell by Osmosis. It helps to maintain a balance (osmotic pressure) in and out of cell.2. ACTIVE TRANSPORTSuch type of molecule transport which require energy. Or Movement of molecules against the concentration by the expenditure of energy through a carrier (i.e. movement of molecules from the region of lower concentration to higher concentration by protein using ATP as energy.SIGNIFICANCEAbsorption of excess food (glucose), ions (K+ and Na+) takes place by Active transport.CONDITIONS It is unidirectional. ATP provides energy. Protein act as carrier.

Active transport is further subdivided into,(1) Phagocytosis and Pinocytosis (Endocytosis).(2) Exocytosis.PHAGOCYTOSISProcess of picking and ingestion of large solid particle by plasma membrane (which can not enter by diffusion, osmosis or active transport).SIGNIFICANCEIngestion of solid food particles.WBCs pick foreign particles (certain bacteria)PINOCYTOSISProcess of fluid intake, for absorbing fluid by forming pinocytic vesicle (the fluid which cannot be absorbed by osmosis, enters through it)SIGNIFICANCEHelps in absorption of harmones, lipids etc.CELL WALLThe cell wall is the outer most covering of a plant cell. It is composed of cellulose (a carbohydrate) and some other chemical substances.This hard covering gives form, firmness and strength to the plant cell.In a young cell it is thin and delicate but in a mature cell it becomes thick due to the deposition of various chemical substances on its inner surface.There are three layer of cell wall.1. MIDDLE (LAMELLA) First formed cell plate. Cementing layer between two daughter cells. Composed of Ca++ and Mg++ pectate. Cells are separated when this layer is dissolved.2. PRIMARY WALL First product of cell synthesized by protoplast. In young cells it is thin and elastic while it becomes thick and rigid on maturity. Made up of Hemicellulose (50%), cellulose (25%) and pectate substances.3. SECONDARY WALL Composed of cellulose. Present inside the primary wall. Can be modified through the deposition of lignin and other substances.NUCLEUSIt control all the activities of the cell and was discovered by Robert Brown in 1831.It consist of the following parts,(1) Nuclear Membrane.(2) Nucleoplasm or Karyoplasm.(3) Nucleolus.(4) Chromatin Network.1. NUCLEAR MEMBRANEThe nucleus is bounded by a double layered membrane which bears pores and is known as “Nuclear Membrane”

2. NUCLEOPLASMInside the nuclear membrane is a structure less fluid called “Nucleoplasm” and highly rich with proteins.3. NUCLEOLUSIt is a patch work of granules rich in R.N.A formed in the nucleus. They may be more than one in a single nucleus. It contains mRNA formed from DNA, later mRNA comes out of nucleus to control protein formation.4. CHROMATIN NETWORKThere is a network of threads dispersed in the karyoplasm called (Chromatin network)Each individual thread is called (Chromosomes).These are made up of DNA and are carrier of genes.NOTE:(Types of Chromosomes from Book Page# 66)MEMBRANE BOUND ORGANELLES(1) ENDOPLASMIC RETUCULUMIt is a complex series of tubules in the cytoplasm. Endoplasmic reticulum are of two types,(1) Agranular or Smooth EPR.(2) Granular or Rough EPR.SMOOTH EPR It has no attached ribosome’s. Function is to synthesis lipid.ROUGH EPR It has ribosome’s attached to its outer surface. Synthesize protein and also transport material within the cell.(2) MITOCHONDRIAAn oval body bounded by a double membrane. The inner membrane is folded to form shelves/incomplete partitions. Which are known as “Crista”, here oxidative enzyme are present. They are sites for aerobic cellular respiration and the energy is produced. Therefore also known as “Power house of cell”(3) GOLGI APPARATUS(DICTYOSOMES)These are thin, plate like structures and are usually located near the nucleus. These are the site of formation of lysosomes and also conjugate protein, modify structure of substances, synthesized by EPR to form lysosomes and secretary vesides. Golgi bodies of plants and lower animals (mostly invertebrates) are known as “Dictyosomes”.(4) LYSOSOMESThey are large, some what irregular structure formed in the cytoplasm formed by golgi-bodies. They contain hydrolytic enzymes which destroys foreign particles. They are also known as “Suicide Sacs” because after secreting the enzymes they digese their own proteins (Autophagy).NOTE:(Lysosomal Storage Diseases From Text Page # 71)(5) PLASTIDSThey are specialized organelles of plant cell that contain pigment or they synthesize reserve substances.They are of three kinds,(A) LEUKOPLAST

leuco = whiteLeukoplast are colourless and store nutrient material.(B)CHLOROPLASTChloroplast are green having chlorophyll that performs photosynthesis.(C) CHROMOPLASTChromo = ColourChromoplast contain different coloured (red, yellow, orange or other than green) pigments. They are found in the cells of different coloured flowers and fruits.(6) MICRO BODIESIt includes peroxisome and glyoxysome.(A) PEROXISOMEThese are the single membrane bounded microbodies contain enzymes for transferring hydrogen atom to oxygen i.e. forming hydrogen peroxide.Hydrogen peroxide is very toxic to the cell therefore it is immediately break down to water by enzyme catalyst.These microbodies help in detoxyfication of alcohal and mostly present in liver cells.(B) GLYOXYSOMEIt is a single layered membrane bound structure containing enzymes which metabolize some molecules in photosynthesis and respiration.They also cause oxidation of fatty acids.CYTOSKELETONCytoskeleton means skeleton of the cell, which is mostly composed of microtubules, microfilaments and intermediate filaments.(A) MICRO TUBULES Microtubules are hollow cylinders with an outerdiameter of 25nm. They are made up of a special type of globular protein tubulin. In single microtubule consist of hundredth of thousands of tubulin sub units, which are usually arranged in 13 columns called Protofilaments. Microtubules are arranged in assemble and disassemble manner. In animal cells and lower plants they also form centriole, cilia and flagella.(B) MICROFILAMENTS Microfilaments are solid structures, thread like with a diameter of 7nm. They are also composed of globular proteins. Each microfilament consist of two actin (Protein) chains that inter wing in a helical fashion.(C) INTERMEDIATE FILAMENTS They are intermediate in size having a diameter of 8nm to 11nm. They are rope like polymers of Fibrous protein. In skin and hair these filaments are made up of protein keratin. They provide mechanical strength to the cell and support the nuclear envelope.

NON MEMBRANE BOUND CYTOPLASMIC ORGENELLE(1)RIBOSOMES These are small structures concerned with protein synthesis in all type of the cells i.e. Prokaryotic as well as Eukaryote. They are freely dispersed in cytoplasm of Prokaryotic cell but in Eukaryotic cells they may be free or attached with endoplasmic reticulum. More than 50 type of proteins are present in ribosome structure and they contain high quantity of RNA. Under the direction of Nucleus ribosome produce the protein made it by the cell. Each Ribosome consist of two unequal parts. These are the smallest and most vital cellular components, manufactured in the nucleolus.(2) CENTRIOLE They are only present in animal cells and certain lower plants. Mostly near the nucleus. Each centriole consist of two cylinders lying perpendicular to one another. Each cylinder consist of nine parallel triplets of hollow cylindrical microtubules. During the cell division they replicate and move towards opposite poles of the cell. In mitosis and meiosis they form thread like fibers which rediate from each centriole are known as mitotic apparatus.(3)VACUOLES These are non-protoplasmic fluid filled cavities in the cytoplasm. Their membrane is known as Tonoplast. They are more prominent in mature cells. In plant cells vacuoles are filled with cell sap and act as store, house. They also play an important role in plant defence. In animal cells vacuole contain hydrolytic enzymes (i.e. lysosomes)

Variety of LifeBASIS OF CLASSIFICATION OF LIVING ORGANISMS The living organisms are classified on the basis of Homology, comparative Biochemistry cytology and Genetics.

(a)Homology(b)Cytology.(c)Bio-chemistry.(d)Genetics(A)HOMOLOGYThe organisms placed in a particular group, all have many fundamental similarities in their structure.EXAMPLEThe flipper, wing and arm are, all build on the same pattern but during the course of evolution, each has been modified from its basic pattern to serve a particular and usually highly specialized function, due to its adaptation different to environment or habitate. (Structures that are similar because of their common origin but may differ functionally is known as Homologus)(B)BIOCHEMISTRYIt is particularly useful, when we classify organism like bacteria, which may all look alike and have an identical cellular structure with the help of chromatography and electrophoresis we can compare the amino acid sequence in the protein of different organisms or the order of bases in their DNA.(C)CYTOLOGYMicroscopic observations of cell structure are also used to make a fundamental split in the classification of living things. They can be useful at the level of generic and species level. This sort of technique can show delicate difference between species or sub-species, which are identical in many other respects. Specie → Genus → Family → Order → Class → Division → Kingdom(D)GENETICSAll the morphological, Bio-chemical properties and cytological aspects of an individual, or of a species depend on its genetic constitution. Hence the final tool helping in classifying an organism is Genetics.TAXONOMIC HIERARCHYThe basic unit of the biological classification is specie. Closely related species are grouped-together into Genera. Genera are grouped into Families, families into order, orders into classes, classes into phyla and phyla or divisions into kingdoms. Each grouping of organisms with in the hierarchy is called taxon and each taxon has a rank and a name. For example class “mammalia” or Genus “Homo”. This ascending series of successively larger, more inclusive groups make up the “Taxonomic Hierarchy”.CHANGES PROPOSED BY MARGUILES AND SCHWARTZ IN THE FIVE-KINGDOM SYSTEMMarguiles and schwartz were American Biologist, put forward a modification of Robert Whittaker’s scheme. According to this modification. The multicellular alga should be removed from the plant kingdom and placed along with all unicellular organisms, in a new kingdom called “PROTOCTIST” which would replace Whittaker’s Protista kingdom. This modification made the plant kingdom a more natural group. Due to this modification the kingdom Protoctista became a kingdom that contains all those organisms, which cannot be fitted into any of the other kingdom.

VIRUSVirus are very minute non cellular bodies considered between living and non-living organisms.DISCOVERY OF VIRUSThe word virus is derived from a Latin word meaning “Poison”. A Russian Biologist Iwanosky in 1892 discovered Virus.CHARACTERISTICS OF VIRUS1. Viruses are non-cellular parasitic entities (obligate parasite)2. Viruses cannot live and reproduce outside the living cells because they lack the machinery to do so by themselves.3. The size of the viruses in range 20nm-250nm.4. Viruses are either virulent destroying the cell in which they occur. While temperate Viruses become integrated into their host genome and remain stable for long period of time.STRUCTURE OF VIRUS1. The viruses may be small sphere like or golf balls, like rod shape tadpole and polyhedral.2. They mainly consist of viral genome, capsids, envelopes and tail Fibers.(A)GENOMEViral genomes may consist of a single or several molecules of DNA or RNA.(B)PROTEIN CAPSID (PROTEIN CORE)The protein coat that encloses the viral genome is called Protein capsid. It may be of different shapes and mainly made up of proteins sub units called “capsomeres”(C)VIRAL ENVELOPESIn some viruses accessory structure called Viral Envelopes are present that help them in infecting their host. They are membranes that enclose the protein core.TAILS AND TAIL FIBRESMany viruses possesses thread like long tail and tail fibers. These structures help in infecting the host. FIGURE / 5.5 (THE STRUCTURE OF BACTERIOPHAGE) PAGE # 91CLASSIFICATION OF VIRUSES(A)ON THE BASIS OF MORPHOLOGYViruses are generally classified on the basis of Morphology and nucleic acids they contain. e.g. On the basis of morphology, Viruses are classified into rod shape (TMV), spherical (Polio Virus) and Tadpole (Bacteriophage Virus).(B) ON THE BASIS OF MODES OF ORIGINViruses can be classified on the basis of their mode of origin, which provide a systematic idea of some of their diversity. Following are the main characteristics of these groups:1. Unenveloped plus strand viruses.2. Enveloped plus strand RNAViruses.3. Minus strand RNA Viruses.4. Viroids5. Double strand RNA Viruses.6. Small genome DNA Viruses.7. Medium genome and large genome DNA Viruses.

8. Bacteriophage.LIFE CYCLE OF THE BACTERIOPHAGEThe virus that infects the bacteria (mostly E.coli) is known as “Bacteriophage”Bacteriophage can reproduce by two alternative mechanisms.1.The lytic cycle2.The Lysogenic cycle.(1)THE LYTIC CYCLEThe life cycle of the bacteriophage that eventually ends in death of the host cell is known as “A LYTIC CYCLE”The following are the stages of lytic cycle.1. Initially the bacteriophage uses his tail fibers to stick to specific receptor present on the outer surface of E-coli bacteria.2. The sheath of the viral tail contracts, thrusting a hollow core through the bacterial wall and membrane of the bacterial cell and then phage injects its DNA into the cell.3. The empty capsid of the phage is left outside the cell.4. The bacterial cell’s DNA is destroyed (hydrolyzed).5. The phage DNA takes control over the bacterial metabolic machinery and uses it to produce phage proteins and viral nucleotide.6. Copies of the phage genome are developed and different parts of the phage come together forming daughter phages.7. In the last stage of lytic cycle the daughter phages released, hydrolytic enzymes “lysozymes”, which digest the bacterial cell wall.8. Due to osmosis, bacterial cell swells and finally burst releasing 100-200 daughter phage particles.FIGURE 5.6 (THE LYTIC CYCLE OF PHAGE-T4) PAGE # 942. THE LYSOGENIC CYCLEThe life cycle of the Bacteriophage in which the viral genome replicates without destroying the host cell is known as lysogenic cycle.Viruses that are capable of using both modes of reproduction with in a bacterium are called “Temperate Viruses”.The following are the stages of lysogenic cycle.(1) In this cycle infection of the E-coli cell begins when the phage binds to the surface of cell and injects its DNA.(2) With in the host cell, the phage DNA molecule forms a circle.(3) The DNA molecules of Viruses incorporated by genetic recombination into a specific site on the host cell’s chromosome. Now it is known as “Prophage cycle”(4) The phage genome is mostly silent with in the bacterium.(5) When E-coli cell prepares to divide, it replicates the phage DNA also, and passes the viral copies to the daughter cells.(6) This mechanism enables the virus to propagate with out killing the host cell upon which it depends.At some point, prophage give rise to the active phages that lyses their host cells. It is usually an environmental trigger such as radiations, or the presence of certain chemicals that convert the virus from the lysogenic to the lytic mode.FIGURE 5.7 PAGE # 95VIRAL DISEASES

1.ANIMAL DISEASES(1) Poliomyelitis.(2) Colds(3) Encephalitis.(4) Dengue fever.(5) Yellow fever.(6) AIDS(7) Rabies.(8) Measles.(9) Mumps.(10) Hepatitis.2. PLANT DISEASES(1) Tobacco Mosaic Virus (TMV) (Tobacco leaves disease) or (Tobacco Mosaic Disease)AIDSCAUSITIVE AGENTAIDS is stand for Acquired Immuno-Deficiency Syndrome, caused by Human Immune Deficiency Virus (HIDV)SYMPTOMS(1) Short flu like illness.(2) Pneumonia like conditions.(3) Disfiguring form of Skin Cancer (Kaposi’s Sarcoma)(4) Weight loss and fever.(5) Dementia (loss of thoughts)(6) Diarrhea (loose motion with increasing frequency)(7) Septicemia (Blood Poisoning)Severity of the Immuno-Deficiency varies and bouts of illness may persist for years.HIV mostly infects lymphocytes and causes brain cell damage, in more than 50% of cases. Irreversible dementia and eventual death occurs.TRANSMISSION(1) The HIV virus can only survive in the body fluids and transmitted by blood or semen.(2) In 90% of cases the transmission occurs by sexual contact. Some other modes of transmission are as follow: Unsterilized syringes and needles mostly in intravenous drug abusers. By giving blood or blood products already infected with HIV. Close contact between infected and non-infected people. From an infected pregnant women to her baby through placenta or through breast milk.CONTROL AND TREATMENTNo particular drug is available for treatment of AIDS but there are some drugs, which are effective against this disease like Azidothymadine, Zidovudine and sumarin.PREVENTION Use of the clean needles and sterilize syringes.

Education and public awareness about the disease and restricted sexual contacts with preventive measures. Tranfusion of screened blood and blood products.HEPATITISHepatitis is an inflammation of the liver cells caused by viral infections, toxic agents or drugs.SIGNS AND SYMPTOMS Jaundice. Abdominal pain. Liver enlargement. Fatigue and fever.TYPES OF HEPATITISThere are various types of Hepatitis few of them are as follow:(1)HEPATITIS “A” Cause by non-enveloped RNA virus. Transmitted by contact with faeces from infected individual. Most common form of Hepatitis world wide.(2)HEPATITIS “B” (SERUM HEPATITIS) Caused by DNA viruses. More common in Asians, Africans and male homosexuals. Often persist in carrier form without causing any symptoms. Transmission mostly occurs through skin contacts, blood transfusion and other medical procedures. (Surgery, NG tube, Catheters) The virus of this disease can cause liver cancer mostly in carriers.TREATMENT AND PREVENTIONNew vaccines against the virus have been produced which are of great importance especially for person who required frequent blood transfusion.(3)HEPATITIS “C” Transmission occurs through mother to child during pregnancy. By sexual contacts. Most common transfusion associated Hepatitis. It causes liver cancers more often than HBV

Kingdom Monera

BACTERIA DISCOVERYBacteria was discovered by A.V. Leuwenhoek in 1676.STRUCTURE OF BACTERIABacteria are smallest and simplest living organism measures from 0.2m to 2 micron in breadth and 2 to 10 micron in length. They are strictly unicellular but some species remain associated with each other after cell division and form colonies.A generalized bacterial cell consists of following structures.(1)FLAGELLAThey are extremely thin appendages, which originate from basal body, a structure in the cytoplasm beneath cell membrane. Flagella help in bacterial locomotion.(2)PILLIThey are hollow, filamentous flagella like appendages, which help in conjugation but not in locomotion.(3)CAPSULEIt is a protective sheath made up of polysaccharides and proteins. It provides greater pathogenicity and protects bacteria against phagocytosis.(4) CELL WALLBacterial cell wall mostly made up of amino acids, sugar and chitin. It surrounds the cell membrane, determine shape and protects bacteria from osmotic lyses. Most bacteria have a unique macromolecule called Peptidoglycan in addition to it. Sugar molecules, teichoic acid, glyco proteins and lipo polysaccharide are also present.(5)CELL MEMBRANE It is present inside the cell wall attached to it at few places containing many pores. It is made up of lipids and proteins. It acts as a respiratory structure.(6)CYTOPLASMBacterial cytoplasm is granular containing many small vacuoles, glycogen particles and ribosomes.(7)MESOSOMES These are the invaginations of the cell membrane into the cytoplasm. They are in the form of vesicles, tubules or lamella. They help in the DNA replication, cell division, respiration and export of enzyme.(8)BACTERIAL HEREDITARY MATERIAL Bacterial hereditary material DNA is found as concentrated structures called Bacterial chromosomes or chromatin bodies. It is mostly scattered in the cytoplasm. A small fragment of extra chromosomal circular DNA, called Plasmid is also present.FIGURE 6.1 (FROM TEXT BOOK)CLASSIFICATION OF BACTERIAON THE BASIS OF SHAPE

On the basis of shape bacteria can be divided into four categories.(1)COCCI These are spherical or rounded bacteria presents in the form of mono, diplo or streptococcus form. They are non-flagellated and cannot move from one place to another place.FIGURE (FROM TEXT BOOK)(2)BACILLI Bacilli are rod shaped bacteria, can be present in the form of diplo or streplobacilli. They may be flagellated and can move from one place to another.FIGURE (FROM TEXT BOOK)(3)SPIRILLA These are spiral or cork, screw shape bacteria also known as spirochetes. It includes chlamydia and rekettia.FIGURE (FROM TEXT BOOK)(4)VIBRIO OR COMMA These are slightly curved bacteria like vibrio cholera. They may be flagellated and can move.ON THE BASIS OF RESPIRATIONOn the basis of respiration bacteria can be divided into two main types.(1)AEROBESRequire oxygen for respiration.(2)ANAEROBESRespire with out oxygenSub-classes of this classification are as follow:(A)FACULTATIVE BACTERIARespire with or without oxygen.(B)MICRO AEROPHILIC BACTERIARequire low concentration of oxygen for growth(C)OBLIGATE ANAEROBESThese bacteria only survive in absence of oxygen.(D)FACULTATIVE ANAEROBESThese bacteria use oxygen but can respire with out it .(E)OBLIGATE AEROBESThese bacteria only survive in the presence of oxygen.ON THE BASIS OF NUTRITIONBacteria can be divided into four main types on the basis of nutrition. Which are as follow.(1)SAPROTROPHIC BACTERIA These bacteria depend on the dead organic matter for their nutrition. They are mostly present in the humus of soil and posses large number of enzymes that convert complex substances of humus to simpler compounds.(2)SYMBIOTIC BACTERIA These bacteria are found associated with other living organism.

They obtain their food from the host without harming it. E.g. Rizobium redicicola (Symbionts in the root nodules of pea family plants).(3)PARASITIC BACTERIA These bacteria grow inside the tissues of other living organism They obtain food at the expense of their host. These bacteria lack certain complex system of enzymes therefore they usually depend upon host cell. E.g. Pneumococcus, Mycobacterium tuberculosis, Salmonella typhi.(4)AUTOTROPHIC BACTERIA These bacteria can sythesize organic compound from simple inorganic substances.Autotrophic bacteria can be divided into photosynthetic or chemosynthetic.(A)PHOTOSYNTHETIC These bacteria contain green pigment chlorophyll, which is known as bacterial chlorophyll, or chlorobium chlorophyll. These pigments are present in mesosomes (invagination of the cell membrane in the cytoplasm) These bacteria utilize H2S during photosynthesis instead of water and liberate sulphur instead of oxygen. sunlight(B) CHEMOSYNTHETIC These bacteria obtain their energy from oxidation of some inorganic substances like iron, hydrogen, nitrogen and sulphur compounds.LOCOMOTION IN BACTERIA Some bacteria can move from one place to another with the help of a wipe like structure flagella. Flagella allow bacteria to disperse into new habitats, to migrate towards nutrients and to leave unfavorable environment. Flagellated bacteria show orientation towards various stimuli, a behavior called Taxis. Some bacteria are chemo tactic, phototectic or magnetotatic.GROWTH IN BACTERIAIn favorable conditions bacteria can grow, very rapidly. There are some factors affecting growth of bacteria such as Temperature, nutrient availability, PH and ion concentration. Bacterial growth can be divided into four main phases, which are as follows(1)LAG PHASEIt is inactive phase during which bacteria prepare them for division.(2)LOG PHASEIn this phase bacteria grow and multiply very rapidly.(3)STATIONARY PHASEIn this phase bacterial multiplication is equal to bacteria death rate.(4)DECLINE/DEATH PHASEIn this phase death is more rapid then multiplication rate.REPRODUCTION IN BACTERIA

Usually asexual reproduction is present in bacteria which is as followFISSIONFission is the fastest mode of bacterial asexual reproduction (Binary Fission) It usually takes place in favorable conditions. Hereditary material DNA in the form of chromatin body replicates. After the replication of hereditary material a constriction appears in the middle of the cell, which later splits it into two parts. Newly form bacterial cells grow in size and form nature bacterial cells. The single fission takes place in 20-30 minutes.ENDOSPORE FORMATION It is the method of bacterial survival under unfavorable conditions. Following are the main characters of this process. During this process, the whole protoplasmic content gets shrink into a small mass. A cyst is formed inside the parental wall around constricted protoplasm to form endospore. On the return of favorable conditions parental wall raptures due to decay and endospore is set free. In the end, this endospore enlarges to form a mature bacterial cell.FIGURE 6.4 (BINARY FISSION IN BACTERIA)FIGURE 6.5 (FORMATION OF ENDOSPORE)GENETIC RECOMBINATION IN BACTERIAGenetic changes with the help of which bacteria adopt new characteristics (drugs resistance pathogenic ability) is known as Genetic recombinationThree types of genetic recombination are present in bacteria, which are given as follow.1.CONJUGATIONSimple process of genetic recombination in which genetic material is transferred from one bacteria to another through a conjugating tube. Conjugation in bacteria was discovered by Joshua Lederburg and Edward L.Tatum in 1946EXPERIMENTJ.laderberg and E.Tatum performed an interesting experiment in order to prove conjugation in bacteria. Following are the main steps of this experiment.1. They selected a wild type bacteria (E-coli) and obtain (triple nutritional mutants) different from one another.2. Wild-type was capable of synthesizing six substances symbolized as A, B, C, D, E and F.3. Mutant type I was capable of synthesizing three substances symbolized as A, B and C but not D, E and F.4. Mutant type II was capable of synthesizing three substances D,E and F but not A,B and C.5. These mutant type I and II were grown together in the growth medium having all the six substances A, B, C, D, E and F.6. After several hours, three types of bacteria were detected after nutritional test which were,

i. Both mutant I and mutant II types.ii. Wild type bacteria synthesizing all the six substances.iii. A new type of bacterial strain requiring all the six substances for growth.In this experiment, appearance of wild type and one new type is an evidence that conjugation had taken place.2. TRANSDUCTIONIt is the mode of genetic recombination in which genetic material is transferred from one bacteria to another by a third party, which is usually bacteriophage.This process was experimentally carried out by Lederberg and Zinder in 1952.EXPERIMENT1. In this experiment, a bacteriophage is made to attack a bacterium known as “donor” (D).2. The injected DNA of bacteriophage multiply to form a large number of daughter phages.3. The donor bacterium (D) gives some of its genetic material “D” to the multiplying particles.4. The phages released from this donor bacterium contain the genetic material of phage plus a little piece of the donor genetic material “D”.5. These new phages then made to attack a new bacterium known as “Recipient” (R).6. These recipient bacterium is not destroyed like the donor in order to reproduce normally. In this way, genetic material of the donor bacterium is carried to the recipient bacterium by a bacteriophage and this process is known as Transduction.3. TRANSFORMATIONIn this process, genetic information transfers from one bacteria to another by producing a change it (undergo a change).This type of genetic recombination was first proved by Fred Griffith in 1928.EXPERIMENTGriffithi injected a small quantity of R-type bacteria and a large quantity of heat killed S-type bacteria into the same mouse.This treatment proved fatal as mouse surprisingly suffered from Pneumonia and died.The autopsy of the mouse revealed the presence of living S-type bacteria in the mouse in addition to R-type.From this experiment Griffith concluded that,The live R-type bacteria had been transformed into live S-type bacteria due to transfer of some material from dead S-type, cells.Thus this transformation occurred due to genetic recombination in R-type bacteria.In his experiment, he had been working on two strains of bacteria “Pnemococcus”. One strain is known as smooth type (Virulent and causes Pneumonia) while the second strain is known as (Rough type (Non-Virulent and does not cause pneumonia).NOTE: (IMPORTANCE OF BACTERIA (USEFUL AND HARMFUL BACTERIA)FROM BOOK PAGE # 116 (OLD BOOK – 2003)VACCINATIONDEFINITION

Inoculation of host with inactive or weaken pathogens or pathogenic products to stimulate protective immunity. In case of subsequent natural infection with the same pathogen the immune system easily recognized the invader and comfortably managed to overcome the pathogen. A vaccine can taken orally (Polio vaccine) or injected into the body (Tetanus Vaccine).IMMUNIZATIONDEFINITIONIt is a process of induction of specific immunity by injecting antigens, antibodies or immune cells. Immunity can be protective or curative in nature. It promotes increased immunity against specific diseases.CYNOBACTERIA (BLUE GREEN ALGAE)MAIN CHARACTERISTICS OF CYNOBACTERIA They are prokaryotic unicellular autotrophic organisms mostly occur in colony form. They posses double layered cell wall. The protoplasm differentiated into an outer colored region chromoplasm, which contain various pigments in which chlorophyll “a” and phycocyanin are more important. Inner colorless region of the protoplasm is known as centroplasm. They are mostly aquatic (fresh water) Sexual reproduction is absent. Asexual reproduction takes place by means of Harmogonia, zoospores, akinates and fragmentation.NOSTOCNostoc is a typical example of blue green algae.STRUCTURE Nostoc is a filamentous prokaryotic algae in which filaments are intermixed in a glatinous mass-forming ball like structure known as coenobium. A single filament look like a chain of beads. Each filament is unbranched and has a single row of rounded or oval cells. Each cell has double layered wall, outer thick wall is made up of cellulose mixed up with pectic compounds. While inner thin layer is made up of cellulose only. The protoplasm is differentiated into an outer colored region (chromoplasm) and an inner colorless region (centroplasm). The chromoplasm various pigments like chlorophyll, axanthophylls, carotene, phycocyanin and phycoerythrin. Ribosome’s, pseudovacuoe and reserve food in the form of cynophyceae starch are present.

Hereditary material is present in cytoplasm with out the nuclear membrane. In Nostoc filaments slightly larger, colorless cells with thick walled known as “Heterocyst” are present. The function o Heterocyst is nitrogen fixation, food storage and multiplication of filament during unfavorable conditions.NUTRITION It is an autotroph and prepares its food in the presence of sunlight. It also capable of fixing atmospheric nitrogen and converts it into nitrates in order to prepare amino acids and proteins, this activity takes place in Heterocysts.REPRODUCTION Only asexual reproduction is present which takes place by following methods.(1)HORMOGONIA A portion of the filaments between two heterocysts is known as Hormogonia. During favorable conditions, filaments break up at the junction of each Heterocyst. The end cells of each homogonous divide to form long filaments of Nostoc.(2)AKINETES It is the method of survival during unfavorable conditions. These are non-motile spores, formed from certain vegetative cells. Each akinete contains an outer layer “exospore” and inner layer “endospores”. On the return of favorable conditions, each akinete germinates by rupturing exospore and formed independent filaments by simple cell division.IMPORTANCE OF CYNOBACTERIA They release oxygen as a by-product during photosynthesis. Many are capable of fixing atmospheric nitrogen. They are first colonizers of moist soil. Nostoc anabena is used as nitrogen fertilizer in agriculture due to its nitrogen fixing ability.MONERA Discovery of bacteria A.V.Leuventoek. Size of bacteria = 0.2-2 micron (breadth) = 2-10 micron (length). Cell wall of bacteria made up of peptidoglycan. Arch bacteria do not contain peptidoglycan. Bacterial replications, cell division, respiration, export of enzymes = By means of mesosomes (invaginations of cell membrane) Saprophytic bacteria form humus (important component of soil)

Photosynthetic bacteria = use H2S in photosynthesis instead of water. Chlorobium chlorophyll or bacterial chlorophyll discovered by Von Nell 1930.DIVERSITY OF LIFE Father of taxonomy = Charles Linneus. Genetics = final tool in classifying living organism. Basic unit of Biological classification = species. Five kingdom system of Robert Whittaker = 1969. Discovery of Virus = Iwanosky 1892. TMV Virus discover by Wendell Stanley in 1935. Size of Virus = 20nm-250nm. AIDS is caused by Human Immune Deficiency Virus (HIV) As a result of lytic cycle of bacterio phage 100-200 daughter phage viruses are produced

The Kingdom Protoctista (Protista)PLANT LIKE PROTOCTIST ULVA: (SEA-LETTUCE)OCCURANCE Ulva, commonly called Sea Lettuce, is a marine green alga. It is found attached to rocks, along the sea coast in intertidal zones (the area between the high tide and low tide mark) In Karachi, it is found on Manora coast.STRUCTURE Ulva exhibits primitive simple multicellular organization. The plant body is a thallus, which is flat, erect , wrinkled and sheet like structure having a length of about 30 cm (1ft). The thallus is very thin and internally it is composed of two vertical rows of cells only. Its lower part forms a “hold fast”, consisting of long thread like cells for attachment to the substratum.

REPRODUCTIONUlva can reproduce sexually as well as asexually.(1)SEXUAL REPRODUCTION Sexual reproduction is isogamous and takes place in sexual plants or gametophyte, which are haploid (n). Each cell of the gametophyte produces many biflagellate gametes, which are released in seawater. The gametes are morphologically similar or isogametes but the fusion takes place between gametes produce by two different gametophyte plants, which are termed as positive strain and the negative strain. Thus, ulva plant exhibits heterothallism (two type of plant body i.e. gametophyte (n) and sporophyte (2n) ulva). After fusion a diploid quadri flagellate zygote is formed. Zygote swims for some time then loses its flagella, secretes a wall around itself and undergoes a period of rest. Finally the zygote germinates and develops into a new diploid ulva plant, which is called asexual plant or sporophyte.(2)ASEXUAL REPRODUCTION Asexual reproduction takes place by formation of quadri flagellate zoospores in diploid asexual plant or sporophyte, which is morphologically similar to gametophyte. Each cell (except the basal cells) of the sporophyte (2n) undergoes meioses or reduction division and forms 8-16 zoospores, which are released in water. After swimming they lose flagella and undergo a period of rest. Each zoospore ultimately developes and forms haploid sexual plant i.e. gametophyte, thus completing the life cycle.ALTERNATION OF GENERATIONA distinct regular alternation of generations between the haploid gametophytes (sexual plant) and diploid sporophyte (asexual plant) is present. Since the two plants are morphologically similar so this process is known as “Alternation of generation (isomorphic)”CHLORELLAFIGURE 7.2 PAGE # 127.OCCURANCE Chlorella is a fresh water alga found floating in stagnant water of ponds, pools and ditches. It is easily cultured and has been used an experimental organism in research in photosynthesis.STRUCTURE The body of chlorella is one celled, spherical in outline and solitary. It contains a single nucleus and a cup-shaped chloroplast usually with out pyrenoid.REPRODUCTION (ASEXUAL REPRODUCTION)

Reproduction takes place by aplanospore formation, which involves the division of protoplast into 8-16 daughter protoplast. Each daughter protoplast secrets a wall to produce a non-motile aplanospore. On release from the parent cell, each aplanospore forms a new vegetative cell.IMPORTANCERecently an antibiotic known as “Chlorellin” useful for the control of bacterial diseases has been prepared from the plant.FUNGI LIKE PROTOCTISTSLIME MOLD (PLASMODIUM STAGE) In initial stages of life cycle, slime mold are creeping masses of living substances, having the consistency of an unboiled egg white and the colour of the yolk. It sends out protoplasmic arms that engulf and digest bacteria from the surface of rotten rock or leaves. This amoeboid stage of slime mold is called plasmodium stage. The plasmodium consists of the cytoplasm in which are embedded many nuclei, food vacuoles and undigested food particles. Plasmodia can move along the forest floor, on to dead leaves that are bathed in sunlight.FRUITING BODY In dry warm environment metamorphosis in Plasmodia takes place and it changes into cluster of fruiting bodies. Depending on the species the fruiting bodies look like golf balls, feathers, bird cages or worm like and in a great variety of colours.REPRODUCTION Each fruiting body produces a large number of microscopic asexual reproductive cells known as spores. Each spore has a single nucleus and a thick protective wall. Germination of the spore occurs when there is plenty of water and suitable temperature. When a slime mold’s spore germinates, it produces one or more tiny cells. Each cell has a pair of flagella that propel it through the film of water, which is necessary for its germination. These flagellated cells some times function as gametes (sex cells) and fuse in pairs. This is true sexual reproduction. Fusion of the gametes forms zygote, which become amoeboid and form a new plasmodium i.e. multinucleated slime moldPHYTOPTHORA INFESTANS(WATER MOLD)This fungi like protoctist belongs to family Oomycotes.It is a pathogenic organism causing. “late blight of potato”STRUCTURE

The mycellium consist of Hyphae which are endophytic, branched, aseptate coenocytic, hyaline and nodulated. The rounded or branched hustoria are found which absorb food material from the host cells.REPRODUCTIONSexual as well as asexual reproductions are present.(A)ASEXUAL REPRODUCTION Asexual reproduction takes place by means of biflagellate zoospores produce inside the productive structure Sporangia. The spores are produced on the branched Sporangiophore in favorable condition. Sporangiophore coming out through the stomata, in groups on the lower surface of infected leaves. The sporangia are produced on the branches of sporangiophore. On maturation, the sporangia the detached from sporangiophore. On maturation the protoplasm of the sporangium converts into uninucleate, vacuolated and naked zoospores. When mature sporangium burst the zoospores liberate in the film.(B)SEXUAL REPRODUCTION Sexual reproduction is zoogamous. The female sex organ is oogonium. while the male sex organ is antheridium. The antherialium develops first and the oosgonium later. Both sex organ may develop on he same Hyphae or on two adjacent Hyphae lying side by side. The oogonium hyphae penetrates the antheridium. The oogonium is pear shaped and contains a single female nucleus in it. The fertilization takes place when the male and the female nuclei fuse in the egg after penetration of the oogonium in the antheridium. There is no fertilization tube and after fertilization the thick walled zoospore developed, which is present inside the oogonium. The oospore germinates in favorable conditions and produce new mycellium. Reduction division occurs during germinates of oospore.ECONOMIC IMPORTANCE The Water Mold causes a disease in potato crop known as “late blight of potato” This disease effects both aerial and underground parts and whole plant becomes blighted in severe conditions. The disease appears in the form of brown spread patches on leaves and rapidly increases to the whole leaf surface. The tuber converts into a rotten pulpy mass emitting foul smell and remains small in size.

A great danger to potato crop and causes sufficient damage of Potato crop.EUGLENAEuglena is an unicellular, flagellated organism. It belongs to the division “Euglenophyta”OCCURANCEEuglena commonly found in drains, ponds and is also present in soil, blackish water and even salt water.DUEL NATURE Euglena has characteristics of both animals and plants. It is more evolved than green Algae.STRUCTURE1. It is somewhat elongated animal, almost pointed at both ends.2. It has definite and easily stainable nucleus.3. It has well defined chloroplast as in higher plants.4. All the Euglena have two flagella usually one of them is long and the other one short by which they can swim activity.5. They lack the outer cellulose cell wall, instead the protoplasm is bounded by a grooved layer called the “Pellicle”.6. Euglena has a gullet near the base of the flagella and an eyespot containing a pigment called “Astaxanthin”.7. Reproduction is usually asexuality by simple division.TAXONOMIC POSITION OF EUGLENA One of the examples of Eukaryotes is Euglena. Belongs to group kingdom Protactista.PLANT LIKE CHARACTERS IN EUGLENA1. Presence of Chloroplast.2. Undergoes physiological, biochemical process of photosynthesis.3. Behaves as natural autotroph in presence of sunlight.ANIMAL LIKE CHARACTERS IN EUGLENA1. Absence of a cell wall.2. Presence of a mouth with cytopharynx.3. Eyespot containing animals pigment called “Astaxanthin”.4. Presence of reservoir.5. Can easily be converted into heterotopy after the loss of chloroplast.ANIMAL LIKE PROTOCTISTAPHYLUM PROTOZOAGENERAL CHARACTERS1. Protozoa are microscopic, unicellular (as single cell performs all vital activities) organisms.2. These organisms are asymmetrical.3. The body of organism may be naked or covered by pellicle to maintain the shape.4. Cytoplasm of protozoans is usually divided into outer, ectoplasm and inner granular endoplasm.5. Cell may be uninucleate or multinucleate. Nuclei are covered by nuclear membrane.

6. Protozoan may be solitary or colonial.7. They are aquatic and are found in both fresh and marine water.8. Nutrition may be holozoic (animal like), halophytic (plant like) or saprozoic (subsisting in dead organic matter) or parasitic.9. Digestion is intracellular and is accomplished inside the food vacuole.10. Locomotion takes place by flagella, cilia or psendopodia.11. Respiration takes place through general body surface.12. One or more contractile vacuoles are present for osmo-regulation.13. Reproduction takes place by both asexual and sexual methods.14. The asexual methods include binary fission, multiple fission and budding.15. Sexual reproductive methods include gamete formation (Isogamies and Anisogamous) or by conjugation.CLASSIFICATIONAbout 30,000 species of protozoa are divided into five classes, which differ in their means of locomotion.1. Class flagellate (Mastigophora).2. Class sarcodina (Rhizopoda).3. Class ciliate (Ciliophora).4. Class suctoria.5. Class sporozaa.(1)CLASS FLAGELLATA1. Locomotary organs are long hair like “Flagella” with are one or two in number.2. Body is enclosed in a thin covering of “Pellicle”.3. Asexual reproduction takes place by longitudinal fission.4. Class Flagella is divided into sub classes.(A)SUB-CLASS PHYTOFLAGELLATA (PHYTOMASTIGMA) Contain chlorophyll and perform process of photosynthesis.Examples: Euglena and Volvax.(B)SUB-CLASS ZOOFLAGELLATA (ZOOMASTIGMA) Does not contain chlorophyll and are heterotrophic.Examples: Trypanosome and Leis mania.Some flagellates are parasites. For example: Trypanosome is a blood parasite human and causes African sleeping sickness. Its carrier is “Tse Tse fly”.(2)CLASS SARCODINA (RHIZOPODA)1. Locomotion takes place by “Psendopodium”.2. Body shape is not definite and keep on changing because the pellicle is absent. Some have external sheats or skeletons.3. Nutrition is mostly holozoic, some are parasite. E.g. Entamoeba, histolytic can cause human dysentery.4. Example:i. Entamoeba histolytic is a parasite living in intestine of man. ii. Foraminifera is a group including shelled sarcodimians. E.g. Polystomella. iii. Heliozoa is a group including fresh water organisms having fine, stiff and ray like psendopodia e.g. Actinophrys.(3)CLASS CILIATA1. Locomotory organs are cilia which are short, thin, protoplasmic structure,

covering the body surface.2. Body shape is definite and maintained by pellicle.3. Many ciliates have a groove or depression called “Gullet” into which food can be brought.This class is divided into two sub-classes.(i) SUB-CLASS PROTOCILIATA Cilia all of equal size and uniformly distributed. Cytosomes absent. Nuclei two to many but all of one type e.g. Opalina(ii) SUB-CLASS ENCILIATE Cilia of different types and not uniformly distributed. Cytosomes usually present. Nuclei of two types types Micronucleus and Meganucleus e.g. Paramecium, Balantidium.(4)CLASS SUCTORIA1. They are closely related to ciliates, therefore both are includes in same sub-phylum i.e. sub phylum Ciliphora.2. Young individual have cilia and swim about but the adults are sedentary and have stalks by which they are attached to the substrate.3. Body bears a group of delicate cytoplasmic tentacles, some of which are pointed to pierce their prey, where as others are tripped with rounded adhesive, knobs to catch and hold the prey.4. The tentacles secrete a toxic material which may paralyze the prey.5. Suctorians have two nuclei i.e. meganucleus and micronucleus.6. Reproduction is by asexual budding. E.g. Acineta, Ephelota.(5)CLASS SPOROZOA1. All are parasites.2. Lomotary organs are absent.3. Body covered by a thick cuticle.4. Asexual reproduction is by multiple fission or sporulation.5. Sexual reproduction is isogamies or anisogamous.6. Examples.i) Plasmodium is a human blood parasite enters the human blood when an infected female Anopheles mosquito bites humans. Plasmodium reproduces asexually in man and sexually in the body of mosquito.ii) Monocytis lives as a parasites in seminal vesicles of earthworm.MALARIAINTRODUCTION“Malaria is an infectious disease marked by attacks of chills fever, sweating occurring at intervals that depends on the time required for the development of a new generation of parasites in the body”.CAUSATIVE AGENTMalaria is caused by a protozoan parasite of the genus PLASMODIUM. It was discovered by LAVERAN in 1878.TRANSMITTING AGENTMalaria is transmitted into the blood of man by the bite of an infected

“FEMALE AND PHELES MOSQUITO”. It was discovered by KING in 1717.SYMPTOMS OF MALARIAThe symptoms of malaria first appear after several days of infection in man. He time taken by parasite before it appears in the blood is called INCUBATION PERIOD.SYMPTOMS DURING INCUBATION PERIODThe symptoms that appears in incubation period: Nausea. Loss of appetite. Constipation. Insomnia. Headache. Muscular pain. Aches in joint develops.USUAL SYMPTOMS OF MALARIA Onset of malarial fever Shauking chills Sweating Rise in body temp. (may be up 106˚)MALARIA – A BIOLOGICAL PROBLEMMalaria has been one of the man’s most important biological problems. Millions of people have been killed only because of his disease. To solve this problem, various biological methods were applied to find out in details. Experiments were performed, observation and data were collected, and finally the complete life cycle of the malarial parasite was studied.STUDYING MALARIA EXPERIMENTALLYIn the experimental study of malaria, several HYPOTHESIS were presented and deductions were made for each of them. Experiments were performed to test the deduction and observations are recorded. If the deductions are proved true, the hypothesis regarded as correct.HYPOTHESIS (1)A hypothesis was made about the malarial parasite plasmodium that: “Plasmodium is the cause of malaria”DEDUCTIONTo test the above hypothesis, the following deductions were made: “If the plasmodium is the cause of malaria, then the patients suffering from malaria should have malarial parasite in their blood”.EXPERIMENTExperiment were carried out by examining blood samples from malarial patients that showed positive result. To prove it further experiments were repeated whenever malaria accured.RESULTIn this way the hypothesis that the “Plasmodium is the cause of malaria” was found to be true.HYPOTHESIS (II)

It was noted that people living around the marshy places were usually have the attack of malaria. Thus the hypothesis was stated “Malaria is associated with marshes”DEDUCTIONTo test the statements, a deduction was made that “If marshes are eliminated”.EXPERIMENTOn experimental basis, marshes were eliminated and as a result the role of infection of malaria was greatly much reduced.RESULTIt was this proved that malaria is associated with marshes. Thus the hypothesis stands true. Thus, it is new understood that accurate methods are essential to understood biological problems.LIFE – CYCLE OF MALARIAL PARASITEDISCOVERYLife cycle of plasmodium in ANOPHELES MOSQUITO was first discovered in 1898.PHASES OF LIFE CYCLEThe life cycle of plasmodium is digenetic involving two phases is two hosts for completion.1. ASEXUAL PHASE IN MAN (PRIMARY HOST)2. SEXUAL PHASE IN MOSQUITO (SECONDARY HOST)1. ASEXUAL CYCLE IN MAN (SCHIZOGONY)

INTRODUCTIONThe life cycle of plasmodium in mass is Asexual and is called SCHIZOGONY, because “SCHIZONTS” are produced.PHASES OF SCHIZOGONYAccording to Graham (1948), the life cycle of plasmodium can be divided into four phases;1. PRE-ERYTHROCYTIC PHASE (LIVER SCHIZOGONY).2. ERYTHROCYTIC PHASE.3. POST-ERYTHROCYTIC PHASE.4. GAMORONY OR GAMETOCYTIC PHASE.EXPLANATION OF SCHIZOGONYINFECTIONA healthy person acquires infection when a female Anopheles mosquito, containing infective stages (SPOROZOITES) of parasite is its salivary gland, bites him for sucking his blood.(1)PRE-ERYTHROCYTIC PHASEOnce with in the human blood, the sporozoites circulate in the blood for about half an hour.INVASION OF LIVERAfter circulation in the blood, the sporozoites get into liver to invade the hepatic cells.SCHIZONT FORMATIONAfter penetrating the liver cells, each sporozoite grows for no. of days and becomes a SCHIZONT.CRYPTOZOITE FORMATION

SCHIZONT divides to form a large number of uninucleate CRYPTOZOITES, which are liberated when the liver cell burst.METACRYPTOZOITE FORMATIONThe released cryptozoites invade the fresh liver cells and multiply producing enormous no. of metacryptozoites.(2) ERYTHROCYTIC PHASETROPHOZOITE FORMATIONThe metacryptozoites after escaping into the blood stream, invade the red blood corpuscles. Each become rounded and is called TROPHOZOITE.SIGNET RING STAGEWhen trophozoite grows in size, the nucleus is pushed to one side into the peripheral cytoplasm. It resembles a signet ring and is preferred to an SIGNET RING STAGE.MEROZOITE FORMATIONThe trophozoite ingesis a large amount of cytoplasm of the R.B.C. The blood H6 is broken down into its protein components, which is used by trophozoite develops into an active amoeboid trophozoite. After active feeding, it becomes rounded and grows in size and become and SCHIZONT. It now undergoes SCHIZOGONY and produces MEROZOITES.RELEASE OF MEROZOITES IN BLOODWith the rupture of RBC’S, the merozoites are liberated into the blood plasma. These invade fresh corpuscles to repeat the cycle. The time taken to complete one erythrocytic cycle depends upon the species of Rasnodium.(3) POST-ERYTHROCYTIC PHASESome merozoites produced in erythrocytic phase reach the liver cells and undergo schizonic development. This is known as Post-Erythrocytic Phase.(4) GAMOGONYFORMATION OF GAMETOCYTESWhen successful asexual multiplication is achieved, the merozoites donot proceed further with the erythrocytic phase but, after entering the RBC, increase in size to form Gamocytes.TYPES OF GAMETOCYTESGametocytes are of two types:1. Male Microgamo Cycle2. Female Macrogamo CycleThe Gametocytes do not divide, but remain within the host blood until they are injected by the vendor, in which they continue their sexual development.SEXUAL CYCLE IN MOSQUITOINTRODUCTIONSexual life cycle of Plasmodium is completed in the gut of Female Anopheles Mosquito resulting in infective Sporozoites. This cycle is completed in 12-23 days.PHASES OF SEXUAL CYCLEThis cycle comprises of following stages:1. Gametogony2. Syngamy or Fertilization3. SporogonyEXPLANATION OF SEXUAL CYCLE

(1) GAMETOGONYGametogony refers to the Formation of Gametes. The gamocytes are taken up along with the blood into the stomach of the mosquito and develop into gametes.FEMALE MACROGAMETEThe female gamocytes soon become macrogamete, which is larger in size and ready to fertilize.MALE MICROGAMETEEach male gamocyte forms 6 to 8 sperms like microgametes by a process of Exflagellation.(2) SYNGANY OR FERTILIZATIONZYGOT FORMATIONWithin the gut of mosquito the two gametes of opposite sexes fuse together to form a zygot. This process is called Syngamy.OKINETE FORMATIONAfter fertilization zygot differentiates into motile worm-like ookinete.OOCYST FORMATIONOokinete penetrates the stomach wall to settle down just under the mid gut. Here after observing nutrients, it develops a cyst around it and becomes spherical. This encysted is called Oocyst.(3) SPOROGONYThe oocyst then enters a phase of asexual multiplication, the Sporogony.SPOROBLAST FORMATIONIn 6 to 7 days, the nucleus of oocyst divides into several nuclei and cytoplasm envelops each one of them and thus hundreds of oval shaped Sporoblasts are formed.SPOROZOITE FORMATIONThe sporoblast nucleus again divides and forms hundreds of filamentous, uninucleated Sporozoites. The cyst bursts and liberated sporozoites migrates to the Salivary Gland where they await to penetrate to a human host

Kingdom FungiKINGDOM FUNGI “Fungi are a group of unicellular to multicellular, thalloid, heterotrophic, eukaryotic living organisms having a body called MYCELLIUM, made up of HYPHAE which are non-chlorophyllous & have cell wall (made up of chitin). Reproduction is usually ASEXUAL by means of spores”.FUNGI ARE NEITHER COMPLETELY PLANTS NOR ANIMALSPreviously fungi were regarded as plants as they resemble the plants in many

characteristics. But in addition fungi have many qualities just like the animals. So they are regarded in the midway between plants and animals.PLANT LIKE CHARACTERISTICS OF FUNGIFungi resemble the plants in Having Cell Wall Lacking Centrioles Being non-motileANIMAL LIKE CHARACTERISTICS OF FUNGIBut Fungi also resemble with animals as they are Heterotrophic Lack cellulose in their cell wall Presence of chitinIt means thatFungi are neither completely plants nor animals.

CONFIRMATIONDetail studies also confirm that Fungi are different from all other organisms.NUCLEAR MITOSISThey have a characteristic mitosis called Nuclear-mitosis, during which nuclear membrane does not break & spindle is formed with in the nucleus.SOME REPRESENTATIVES OF KINGDOM FUNGISome imp. Examples are as follows:- YEAST MUSHROOMS PENICILLIUM MOLD MUCOR RHIZOPUSSTRUCTURE OF BODY OF FUNGUSMYCELIUMThe complete multicellular body of fungus is called MYCELIUM, which is composed of white fluffy mass of branched hyphae.HYPHAEA few of true fungi are unicellular (such as yeast) but most have multicellular body (mycelium) consisting of long, slender, branched, tubular, thread like filaments called as Hyphae which spread extensively over the surface of substrate.HYPHAETYPES OF HYPHAEHyphae can be divided in to two types:1. Septate or Multicellular Hyphae2. Non-septate or multinuclear or coenocytic hyphae.1.SEPTATE HYPHAE

DEFINITION

“Those hyphae which are separated by cross-walls called “septa” into individual cells containing one or more nuclei , are called “Septate Hyphae”

EXAMPLE: Mushrooms2. NON-SEPTATE HYPHAEDEFINITIONThose hyphae, which lack septa & are not divided into individual cells, instead these are in the form of long, multinucleated large cells are called Non-septate or Coenocytic Hyphae.EXAMPLE Mucor & RhizopusCELL WALL OF HYPHAECHITIN is the chief component present in the cell wall of most fungi, Because it is more resistant to decay than are the Cellulose & lignin which make up plant cell wall.CYTOPLASM OF HYPHAEIn septate Hyphae —– Cytoplasm flows through the pores of septa from cell to cell, carrying the materials to growing tips & enabling the hyphae to grow rapidly, under favorable conditions. In non-septate hyphae —— cytoplasm moves effectively, distributing the materials throughout.NUCLEI OF HYPHAEAll fungal nuclei are HAPLOID except for transient diploid zygote that forms during sexual reproduction.MAIN FUNCTION OF HYPHAEExtensive spreading system of Hyphae provides enormous surface area for absorption.NUTRITION IN FUNGIABSORPTIVE HETEROTROPHSAll fungi lack chlorophyll & are heterotrophs ( obtain carbon & energy from organic matter, They obtain their food by direct absorption from immediate environment & are thus “ABSORPTIVE HETEROTROPHS”.DIFFERENT MODES OF HETEROTROPHIC NUTRITION IN FUNGIBeing Heterotrophic, fungi can exist as1- Saprotrophs or saprobes ( Decomposers )2- Parasites3- Predators4- Mutualists1. SAPROBIC OR SAPROTROPHIC FUNGI ( DECOMPOSERS)Saprobic fungi along with bacteria, are the major decomposers of biosphere, contributing to the recycling of the elements (C,N,P,O,H & etc) used by living things.DEFINITION“Those fungi which obtain their food (energy, carbon & nitrogen), directly by digesting the dead organic matter are called “SAPROBIC FUNGI” OR “DECOMPOSERS”MECHANISM OF ABSORBING FOOD (DEVELOPMENT OF RHIZOIDS)These fungi anchor to the substrate by modified hyphae, the RHIZOID, which provide enormous surface area for absorptive mode of nutrition.SECRETION OF DIGESTIVE JUICES

Saprobic fungi secrete digestive juices, which digest organic matter & the organic molecules thus produced are absorbed, back into the fungus.2. PARASITIC FUNGIDEFINITIONThose fungi which absorb nutrients directly from living host cytoplasm are called PARASITIC FUNGI.MECHANISMFor obtaining, their food requirements, these fungi develop specialized hyphal tips called as HAUSTORIA which penetrate the host tissues for absorbing nutrients.TYPES OR PARASITIC FUNGIParasitic fungi may be of two typesA. OBLIGATE PARASITESB. FACULTATIVE PARASITES.(A) OBLIGATE PARASITESDEFINITIONThose parasitic fungi which can grow only in their living host & cannot be grown on available defined growth culture medium, are called “ Obligate Parasites”.EXAMPLESMany mildewsMost of Rust species.(B) FACULTATIVE PARASITESDEFINITION“Those parasitic fungi which can grow parasitically on their host as well as by themselves on artificial growth media, are called “ Facultative Parasites”.3. PREDATORY FUNGIDEFINITION“Those fungi which obtain their food by killing other living organisms are called PREDATORY FUNGUSEXAMPLES1. Oyster Mushrooms ( Pleurotus astreatus ).2. Some species of Arthrobotrys.MECHANISM OF OBTAINING FOOD1. IN OYSTER MUSHROOMSOyster mushroom is a carnivorous fungus. It Paralyses the nematodes (that feed on this fungus), penetrate them & absorb their nutritional contents, primarily to fulfill nitrogen requirements. It fulfill it glucose requirements by breaking the woods.2. IN ARTHROBOTRYSConstrictor ring developmentSome species of Arthrobotrys trap soil nemotodes by forming CONSTRICTING RING, their hyphae invading & digesting the unlucky victim.4. MUTUALISTIC FUNGIDEFINITION“Those fungi which form such symbiotic associations with other living organisms in which both partners of association get benefit from each other are called MUTUALISTIC FUNGI & Such association are called as “MUTUALISTIC

SYMBIOTIC ASSOCIATIONS”TWO MUTUALISTIC SYMBIOTIC ASSOCIATIONS FORMED BY FUNGIFungi form two key mutualistic symbiotic associations. These are:1. LICHENS2.MYCORRHIZAE1. LICHENSSYMBIOTIC PARTNERS IN LICHENSLichens are mutualistc & have symbiotic associations b/w certain fungi (mostly Ascomycetes) & imperfect fungi & few Basidiomycetes (about 20 out of 15000 species of lichens) & certain photoautotroph either green algae or cynobacterium or sometimes both.MUTUAL BENEFITIn lichens, fungi protect the algal partner from strong light & desiccation & itself gets food through the courtesy of alga.AREAS WHERE LICHENS GROWLichens can grow at such places such as bare rocks & etc, where neither of the components alone can grow.ECOLOGICAL IMPORTANCE OF LICHENSFrom ecological point of view, lichens are very important because they serve as BIO INDICATORS of AIR POLLUTION.2. MYCORRHIZAESYMBIOTIC PARTNERSMycorrhizae are mutualistic association b/w certain fungi & roots of vascular plants (about 95% of all kinds of vascular plants).MUTUAL BENEFITThe fungal hyphae dramatically increase the amount of soil contact & total surface area for absorption & help in direct absorption of nutrients from soil. The plant on the other hand, supplies organic carbon to fungal hyphae.TYPES OF MYCORRHIZAEThere are two main types of mycorrhizae.1. Endomycorrhizae2. Ectomycorrhizae1. ENDOMYCORRHIZAEIn Endomycorrhizae, the fungal hyphae penetrate the outer cells of plant root, forming coils, swellings & minute branches, & also extend out into surrounding soil.2.ECTOMYCORRHIZAEIn Ectomycorshizae the hyphae surround & extend between the cell but don’t penetrate the cell walls of roots.EXAMPLEMutualistic association between fungi & pines & firsREPRODUCTION IN FUNGITwo kinds of reproduction are usually found in Fungi1. ASEXUAL REPRODUCTION2. SEXUAL REPRODUCTIONExcept In perfect Fungi in which sexual reproduction has not been observed.1. ASEXUAL REPRODUCTIONDEFINITIION

The most common means of reproduction in fungi which does not involve sexes, reduction division & fertilization is called A SEXUAL REPRODUCTIONDIFFERENT MODES OF ASEXUAL REPRODUCTIONIn fungi , asexual reproduction take place by following ways:1- SPORE FORMATION2- CONIDIA FORMATION3- FRAGMENTATION4- BUDDING.1- SPORE FORMATIONINTRODUCTIONIt is the most common type of asexual reproduction in fungi in which large no of spores are developed with in the sporangia. Each spore on generation produces another mycelium.EXPLANATION OF THE PROCESSSPORESSpores may be produced by sexual or asexual process, are haploid, thick walled, non-motile & not needing water for their dispersal, They are very small & produced in very large no. with in the SPORANGIUM.SPORANGIUMSpores are produced inside the reproductive structures called SPORANGIA, which develop as swellings at the tips of SPORANGIOPHORES.SEPARATION OF SPORANGIUM FROM HYPHAEAfter the formation of spores, sporangium becomes separated from hypae by a complete septa.BREAKAGE OF SPORANGIAL WALLOn maturity of the spores, the outer wall of sporangium breaks down & spores are dispersed.DISPERSION OF SPORESSpores are usually dispersed by air currents to great distances & cause wide distribution of many kinds of fungi. They may also be dispersed by small animals & insects & by rain splashes.GERMINATION OF SPORESIn a favorable condition, on a proper substrate, the spore germinates giving rise to new fungal hyphae.2.CONIDIA FORMATIONINTRODUCTIONThe type of asexual reproduction in fungi in which large number of asexual spores called “CONIDIA are formed, each on germination giving rise to new mycelium is known as CONIDIAL REPRODUCTION.EXPLANATIONCONIDIAConidia are non-motile, asexual spores which may be produced in very large number & can survive for weeks, causing rapid colonization on new food.CONIDIOPHORESConidia are not developed inside the sporangium but they are usually cut off at the end of modified hyphae called CONIDIOPHORES, commonly in chains or clusters.EXAMPLE

Asexual reproduction by conidia formation is very common in ASCOMYCETES.3.FRAGMENTATIONIt is the type of asexual reproduction in which mycelium of some fungal hyphae breaks into pieces or fragments. Each fragment develops into a new mycelium.4. BUDDINGINTRODUCTIONBudding is an asymmetric asexual division in which tiny outgrowth or bud is produced which may separate & grow by simple relatively equal cell division into new mycelium.EXAMPLEUnicellular yeasts reproduce by buddingSEXUAL REPRODUCTIONINTRODUCTIONDetails of sexual reproduction very in different groups of fungi on the basis of which fungi can be divided into four major phyla, However the fusion of haploid nuclei & meiosis are common to all.EXPLANATIONSexual reproduction in fungi takes place through several stages, which are as follows.PLASMOGAMYWhen fungi reproduce sexually, hyphae of two genetically different but compatible mating types come together & their cytoplasm fuse. This process is called PLASMOGAMY, This step is common in all types of fungi.IN ZYGOMYCOTAIn Zygomycota after Plasmogamy following steps occur.KARYOGAMYIn zygomycetes, Plasmogamy is followed by fusion of nuclei, called as KARYOGAMYZYGOT FOMATION & MEIOSISIn ZYGOMYCETES, fusion of nuclei, leads directly to the formation of zygot, which divides by meiosis when it germinates.IN ASCOMYCOTA AND BASIDIOMYCOTAIn these groups of fungi, following steps after plasmogamy.FORMATION OF DIKARYOTIC NYPHAEIn these groups, the two genetic types of haploid nuclei from two individuals my coexist & divide in the same hyphae for most of the life of fungus. Such as fungal hyphae is called DIKARYOTIC OR HETEROKARYOTIC HYPHA/CELL.FORMATION OF FRUITING BODIESExtensive growth of dikaryotic hyphae may lead to the formation of massive structures of interwoven hyphae called as Fruiting Bodies, such as Basidia/ Basidiocarps Asci/ AscocarpsSYNGAMY & MEIOSISFusion of two haploid nuclei occurs with in the fruiting bodies forming a zygote, This is called as SYNGAMY, followed immediately by meiosis.FORMATION OF HAPLOID SEXUAL SPORESEach zygote divides immediately by meiosis to form four haploid spores, which

when release are dispersed, some of them giving rise to new hyphae.CLASSIFICATION OF FUNGIThere are four major divisions of fungi, which are divided on the basis of their sexual reproduction.1- ZYGOMYCOTA2- ASCOMYCOTA3- BASIDIOMYCOTA4- DEUTEROMYCOTA1- ZYGOMYCOTAINTRODUCTIONZygomycota are by far the smallest of four groups of fungi, with only about 600 named species. This group includes more frequently bread molds as well as a variety of other microscopic fungi found on decaying organic material.CHARACTERISTIC FEATUREThe group is named after a characteristic feature of the life cycle of its member, the production of temporalily dormant structures called ZYGOSPORES.The zygomycetes lack septa in their hyphae i.e coenocytic hyphae, except when they form sporangia or gametangia.LIFE CYCLE OF ZYGOMYCOTAIn the life cycle of zygomycota, two types of reproduction occurs:A- SEXUAL REPRODUCTION IN ZYGOMYCOTAB- ASEXUAL REPRODUCTION IN ZYGOMYCOTA(A) SEXUAL REPRODUCTION IN ZYGOMYCOTASexual reproduction takes place by fusion of GAMETANGIA in following steps:FORMATION OF PROGAMETANGIUMWhen two hyphae came in contact with each other, each of them gives a lateral progametangium, facing each other.DIFFERENTIATION OF PROGAMETANGIA INTO GAMETANGIA & SUSPENSORSLater on, each of the progametangium differentiates into two parts Apical swollen part called GAMETANGIUM, containing numerous nuclei Basal hollow part called SUSPENSOR.GAMETANGIAL COPULATIONThe gametangia may be formed on hyphae of different mating types or on a single hyphae. If different mating types are involved, fusion between pairs of haploid nuclei occurs immediately.ZYGOT FORMATIONFusion of haploid nuclei results in formation of diploid zygote nuclei, Except for the zygote nuclei, all nuclei of zygomycota are haploid.ZYGOSPORE FORMATIONAfter the formation of diploid zygote nuclei, the fused portion of hyphae develops into ZYGOSPORES.GERMINATION OF ZYGOSPOREUnder favorable condition zygospore germinates & giving rise to new mycelium. Meiosis occurs during germination.(B) ASEXUAL REPRODUCTION IN ZYGOMYCOTA (BY SPORE

FORMATION )Asexual reproduction occurs much more frequently than sexual reproduction in the zygomycetes.EXPLANATIONAs previously discussed in spore formationEXAMPLES OF ZYGOMYCETES1- MUCOR2- RHIZOPUS STOLONIPER2-ASCOMYCOTAINTRODUCTIONThe second division of fungi, the ASCOMYCOTA is a very large group of about 30,000 named species with many more being discovered each year.CHARACTERISTIC FEATUREThe ascomycota are named for their characteristic reproductive structure, the microscopic, club shaped ASCUS.TYPE OF HYPHAEThe hyphae of ascomycetes are divided by septa i.e septate hyphae, but the septa are perforated & the cytoplasm flows along the length of each hyphae. The septa that cut off the asci & conidia are initially perforated like all other septa, but later they often become blocked.LIFE CYCLE OF ASCOMYCOTAIn life cycle of ascomycota, Both sexual & asexual reproduction occurs.

(A) SEXUAL REPRODUCTION IN ASCOMYCOTASexual reproduction occurs through following steps.1-FORMATION OF MALE GAMETANGIUM OR ANTHERIDIUMThe hyphae of ascomycetes may be either homokaryotic & heterokaryotic. The cells of these hyphae usually contain from several to many nuclei. These cells form Antheridium or male gametangium.2-FEMALE GAMETANGIUM OR ASCOGONIUMThe gametangium which develop beak like out growth called as TRICHOGYNE, is called female gametangium or Ascogonium.3-FUSION OF MALE & FEMALE GAMETANGIUMWhen antheridium is formed , it fuses with trichogyne of an adjacent ascogonium. Fusion of cytoplasm or plasmogamy occurs.4-PAIRING OF NUCLEIAfter plasmogamy, nuclei from antheridium then migrate through the trichogyne into the ascogonium, & pair with nuclei of opposite mating types.5-FORMATION OF DIKARYOTIC HYPHAE & DIKARYOTICYDikarytic hyphae then arise from the area of fusion. Throughout such hyphae, nuclei that represent the two different original mating types occur ( DIKARYOTICY ) Such hyphae are also called as HETEROKARYOTIC HYPHAE.6-FORMATION OF ASCOCARPS OR FRUITING BODIESExcessive growth of monokaryotic or dikaryotic hyphae results in formation of massive structures of tightly interwoven hyphae, called as FRUITING BODIES OF ASCOCARPS, which corresponds to the visible portions of a morel or cup fungus.7- ASCI FORMATION

Asci are special reproductive structures which are formed on special fertile layers of dikaryotic hyphae with in the Ascocarps.8- SEPARATION OF ASCI-+The asci are cut off by the formation of septa at the tips of heterokaryotic hyphae.9- SYNGAMYThere are two haploid nuclei with in each ascus one of each of which belongs to different mating type. Fusion of these two nuclei occurs within each ascus called as SYNGAMY.10-ZYGOT FORMATIONSyngamy results in zygote formation, which divides immediately by meiosis, forming four haploid daughter cells.11- FORMATION OF ASCOSPORESFour haploid daughter nuclei, usually divide again by mitosis , producing 8 haploid nuclei that become walled & called ASCOSPORES.12-BURSTING OF ASCUSIn most Ascomycetes, the ascus becomes highly turgid at maturity and ultimately bursts, often at a perforated area, which may be pore or slit or lid13- DESPERSION & GERMINATION OF ASCOSPORESAfter bursting, the ascospores may be thrown as far as 30 cm. Under favorable circumstances they germinate giving new hyphae.TYPES OF ASCOCARPS IN ASCOMYCETESAccording to their shape, Ascocarps are of following three types:1- OPOTHECIUMThe ascocarps of cup fungi & the morels are open, with the asci lining the open cups called OPOTHECIUM.2- CLEISTOTHECIUMSome ascocarps are closed & called as ‘CLESTOTHECIUM’3- PERITHECIUMSome ascocarps have small opening at the apex called as PERITHECIUM. Ascocarps of NEUROSPORA are of this type.(B) ASEXUAL REPRODUCTION IN ASCOMYCOTA (BY CONDIA FORMATION)INTRODUCTIONThe type of asexual reproduction in fungi in which large number of asexual spores called “CONIDIA are formed, each on germination giving rise to new mycelium is known as CONIDIAL REPRODUCTION.EXPLANATIONCONIDIAConidia are non-motile, asexual spores which may be produced in very large number & can survive for weeks, causing rapid colonization on new food.CONIDIOPHORESConidia are not developed inside the sporangium but they are usually cut off at the end of modified hyphae called CONIDIOPHORES, commonly in chains or clusters.EXAMPLEAsexual reproduction by conidia formation is very common in ASCOMYCETES.3.BASIDIOMYCOTAINTRODUCTION

The basidiomycetes, third division of fungi have about 16,000 named species. More is known about some members of this group than about any other fungi.CHARACTERISTIC FEATUREBasidiomycetes are named for their characteristic sexual reproductive structures, the BASIDIUM, which is club shaped like as ascus.LIFE CYCLE OF BASIDIOMYCOTAIn life cycle of Basidiomycota, reproduction is usually sexual. Asexual reproduction is not very important.(A) SEXUAL REPRODUCTION IN BASIDIOMYCOTAThe life cycle of basidiomycetes begin with the production of hyphae which may be of two types.1- Homokaryotic hyphae giving rise to primary mycelium.2- Heterokaryotic hyphae giving rise to secondary mycelium.PRIMARY OR MONOKARYOTIC MYCELIUMHomokaryotic or monokaryotic hyphae lack septa at first. Eventually, However, septa are formed between nuclei of these hyphae. A basidiomycete mycelium made up of monokaryotic hyphae is called PRIMARY MYCELIUM.SECONDARY OR DIKARYOTIC MYCELIUMMycelium of basidiomycetes, with two nuclei, representing the two different mating types b/w each pair of septa, is called SECONDARY OR DIKARYOTIC MYCELIUM. Most of the mycelium of basidiomycetes that occur in nature is dikaryotic & often only dikaryotic mycelium is able to form basidiocarps.FORMATION OF BASIDIOCARP OR FRUITING BODYDikaryotic mycelium is responsible for the formation of FRUITING BODY in Basidiomycetes called as BASIDIOCARP, made up of tightly interwoven dikaryotic hyphae.FORMATION OF BASIDIUMBasidium is characteristic reproductive structure of Basidiomycetes, which is club shaped & formed with in the Basidiocarp. This produces slender projection at the end called as STERIGMATA, in this way.SYNGAMY & ZYGOT FORMATIONNuclear fusion or syangamy occurs in Basidium, giving rise to diploid zygote, the only diploid cell of the life cycle.MEIOSIS & BASIDIOSPORE FORMATIONMeiosis occurs immediately after the formation of zygot, resulting in the formation of four haploid nuclei, which are incorporated in Basidiospores. In most member of this division basidiospores are borne at the sterignataDISPERSION AND GERMINATIONSame as in Ascomycetes(B) ASEXUAL REPRODUCTION IN IN BASIDIOMYCOTAIn contrast to their effective sexual reproduction, asexual reproduction is rare in most basidiomycetes.EXAMPLES OF BASIDIOMYCETES MUSHROOMS TOAD STOOLS PUFF BALLS JELLY FUNGI

SHELF FUNGI PLANT PATHOGENS CALLED RUSTS & SMUTS,4.DEUTEROMYCOTA (FUGI IMPERFECTI)INTRODUCTION“The fungi that are classified is this group, are simply those in which the sexual reproductive stages have not been observed. In other words, most of the Fungi Imperfecti are as ascomycota that have lost the ability to reproduce sexually. There are some 17000 described species of this group.”CHARACTERISTIC FEATURESexual reproduction is absent among Fungi ImperfectiLIFE CYCLE OF DEUTEROMYCOTAAlthough in life cycle of deuteromycetes or Fungi Imperfecti, true sexual reproduction is absent, but there is certain type of GENETIC RECOMBINATION which seems to be responsible for some of the production of new pathogenic strains of wheat rust.GENETIC RECOMBINATION IN FUNGI IMPERFECTI PARASEXUALITYIn parasexuality, exchange of portions of chromosomes between the genetically distinct nuclei with in a common hyphae takes place. This is the special type of genetic recombination occurs in fungi Imperfecti.EXAMPLES OF FUNGI IMPERFECTIAmong the economically important genera of Fungi Imperfecti are1-PENICILLIUM2- ASPERGILLUS3- Most of the fungi that cause skin diseases in humans, including athlete’s foot & ring worm are also fungi imperfecti.ECONOMIC IMPORTANCE OF FUNGIFungi play a vast role in economic field they show both harmful & useful activities to human beings.USEFUL FUNGIFollowing are some of the beneficial effects of fungi.FOODMany kinds of edible fungi are in the form of mushrooms, are a source of nourishing & delicious food dishes. But not all the mushrooms are edible. Some of them are poisonous & called as toad stools or death stool. Yeast, another kind of fungi, are utilized in baking industry.MEDICINESNearly two dozens antibiotics have been isolated from different types of fungi & bacteria, like Penicilliun from penecillium notatum Neomycin Chloromycetin Tetramycin & etc.FOOD PRODUCTIONMany kinds of Yeast are used in the production of bakery & brewery products. Some species of genus PENICILLIUM give characteristic flavors & aromas to the cheese.

FERMENTATIONSpecies of Aspergillus, are used for fermenting soya sauce & soya paste. Citric Acid is produced commercially with members of this genus under highly acidic condition.SOIL FERTILITYFungi maintain the soil fertility by decomposing the dead organic matter e.g Mycorhizal fungi.PRODUCTION OF ORGANIC COMPOUNDSMay species of fungi are used in the production of organic compound such as vitamins, proteins & fats. Saccharomyces, synthesizes a range of vitamin B group.HARMFUL FUNGIFollowing are some of the harmful effects of fungi,FOOD SPOILAGESaprophytic fungi cause tremendous amounts of spoilage of food stuff. 15-20% of worlds fruit is lost each year due to fungal attack.SPOILAGE OF WOOD & LEATHER ARTICLESMany fungi spoil leather goods, woods, wool, books, timber, cotton & etc. WOOD-ROTTING FUNGI destroy not only living trees but also structural timber. BRACKET/SHELF FUNGI cause lot of damage to store cut lumber as well as stands of timber of living trees.TOXINSMany fungi are poisonous . AMANITA VERNA is a mushroom, which produces deadly poisonous substance known as AMANITIN, which causes serious problems in respiratory system & blood circulatory system.FOOD POISONINGSome fungi during decomposing food release certain poisonous substances collectively known as MYCOTOXINS. Mycotoxins are the major source of food poisoning.DISEASESFungi cause a number of diseases in plants as well as in human beings.PLANT DISEASES CAUSED BY FUNGIFungi destroy many agricultural crops, fruits, ornamentals & other kinds of plants because they produce several enzymes that can breakdown cellulose, Lignin and even cutin. Following are some of the serious plant disease caused by Fungi.RUST & SMUT DISEASESRust & smut diseases are serious diseases of WHEAT, RICE, CORN &other cerial crops. They cause extensive damage.POTATO BLIGHTA serious disease of potato caused by a fungus known as PHYTOPTHORA INFESTANS. Other plant disease are. Powdery mildews ( on grapes, rose, wheat & etc). Ergot of rye Red rot of sugar cane Potato will Cotton root rot

Apple scab Brown rot of peaches, plums, apricots & cherries.ANIMAL DISEASES CAUSED BY FUNGIFollowing are some of the fungal diseases in man.SKIN DISEASESRING WORM & ATHELETE’S FOOT are superficial fungal infection caused by certain Fungi InperfectiORAL THRUSHCANIDIA ALBICANS, a yeast causes oral & Vaginal thrush.ASPERGILLOSISAspergillosis is the disease of ear & lungs caused by ASPERGILLUS. It occurs only in person with defective immune system such as AIDS & cause death.CANCERSome strains of ASPERGILLUS FLAVUS produce one of the most carcinogenic ( cancer causing ) mycotoxins called AFLATOXINS.ERGOTISMErgotism is caused by eating bread made from PUROLE ERGOT- Contaminated flour. The poisonous material in the ergot causes nervous spasm, convulsions, psychotic delusion & even gangrene.HISTOPLASMOSISHistoplasmosis is a serious disease of lungs caused by inhaling spores of a fungus, which is common in soil contaminated with bird’s feces

Kingdom PlantaeINTRODUCTION Includes all eukaryotic multicellular and chlorophyllous living organisms, which have cell wall made up of true cellulose. Majority of members are autotrophic but few are parasite e.g.: “Cuscuta” They have localized growth, regions of growth lying primarily at the extremities that is root and stem apices.CLASSIFICATION OF KINGDOM PLANTAEKingdom planatae is divided into tow sub-kingdom on the basis of presence or absence of vascular tissue (xylem and phloem).A – SUB-DIVISION – BRYOPHYTES (NON-VASCULAR) Class Hepatica (Liverworts)

Class Musci (Mosses) Class Anthroccrota (Hornworts)B- SUB-DIVISION – TRACHEOPHYTES Class Psilopsida (Psilopsids) Class Lycopsida (Club Mosses) Class Sphenopsida (Horse Tails) Class Pteropsida (Ferns) ClassSpermopsida (Seed Plants)SUB –DIVISION BRYOPHYTA (AMPHIBIAN PLANTS) OR (NON-VASCULAR PLANTS) Absence of lignin-fortified tissue to support tall plants on land. Members of this sub-division usually sprawl horizontally as mats over a large surface. Always have a low profile (1-2cm-20cm tall).Regular heteromorphic alternation of generation is present w/t gametophytes dominancy (Gametophytes large and long lived). Sporophyte stage of bryophytes is generally smaller and shorter lived, and it depends on gametophyte for water and nutrients. The diploid sporophyte produces haploid spores via meiosis in a structure called “sporangium” The tiny, spores, protected by sporopollenim, disperse and give rise to new gametophytes. All members of bryophytes need water to reproduce. Gametes produce within reproductive structures “Gametangia” (Male-Antheridia and Female-Archer-gonium) Antheridium produces flagellated sperm while female archegonium contains one egg (ovum). Fertilization occurs w/t in the archegonium Zygote develops into an embryo within the protective jacket of Archegonium. Windblown spores disperse the speies. All bryophytes belong to Silurian/Devonian period (345-395Million yrs. Ago.)ADAPTATION OF BRYOPHYTES TO LAND HABITATAll Bryophytes show amphibious form of land plants. Following are main adaptations exhibited by them.a. Rhizoid for water absorptionb. Conservation of waterc. Absorption of CO 2d. Heterogamye. Protection of reproductive cellsf. Formation of embryos

CLASSES OF BRYOPHYTES1-MUSCI (MOSSES) Plants grow in a tight pack, in the form of mat, in order to hold one another up. Mat of moss possess spongy quality and enables it to absorb and retain water. Rhizoids are elongated cells or cellular filaments of mats which grip the substratum. Photosynthesis occurs in upper part of the plant w/c has many small stem like and leaf like appendages. E.g Funaria.2-HEPATICAE (LIVERWORTS) Usually present in tropical areas Plant body is divided into lobes somewhat of the lobed liver, of an animal. These plants are less fimiliar than Mosses.E.g Marchantia3- ANTHROCERATAE:- (HORNWORTS) These plants resemble w/t liverworts, but are differentiated by their sporophytes plants. Sporophyte are elongated capsules that grow like horn from mat like gametophyte. Sporophyte has stomata and chloroplast, performs photosynthesis Sporophyte plant can survive even often the death of gametophyte due to presence of Meristem. Meristem is a specialized tissue, which keeps on adding new cells in sporophyte plant. Hornworts are the most advanced members of bryophytes.E.g ArthrocerosSUB-DIVISION TRACHEOPHYTA (VASCULAR PLANTS)Main characters are as follow, Conducting vessels Xylem and Phloem are present in plant body. A protective layer of sterile “Jacket” cells around reproductive organs are present. Multicellular embryos retained within the archegonia. On aerial parts protective covering “Cuticles” is present w/c prevents excessive loss of water during hot climate. In life cycle Sporophyte stage is dominant.CLASSES OF TRACHEOPHYTES1-PSILOPSIDA These are the fossil representatives of the vascular plants, belonging to “Silurain period” and “Devonian Period” Sporophytes are simple dichotomously branching plants. True leaves and true roots absent. Underground stems that contain unicellular rhizoid similar to root hairs.

The aerial stems are green and carry out photosynthesis. Lacking secondary growth due to absence of “Cambium” Reproductive structure “Sporangia” develop at the tips of some of the aerial branches. Meiosis produces haploid spores, within the sporangia.E.g. Rhynia, Psilotum TemesipterisA) RHYNIA (FIRST VASCULAR PLANT) One of the most primitive vascular plant It is an extinct genus, was named often the village “Rhynia of Scotland where the first fossils of Rhynia were discovered. It belongs to Devonian period, which started about 400 million years ago. The fossils of this plant are so well preserved that the stomata are still intact.STRUCTURE The plant body (Sporophyte) was simple. It consisted of slender, dichotomously branched creeping rhizome, bearing erect, dichotomously branched aerial stem. Instead of roots, rhizoids were given out from rhizome. The aerial branches were leaf-less having terminal fusiform naked sporangia.MICROSCOPIC STRUCTURE The internal structure of branches show a solid central core of vascular tissues surrounded by Cortex. The outer most layer is Epidermis having stomata. The vascular tissue is differentiated into centrally placed xylem and surrounded phloem(FIGURE 9.06(a) Reconstruction of Rhunia) TEXT BOOK BIO-XI Pg# 170B) PSILOTUM AND TEMESIPTERIS (LIVING SPECIES OF PSILOPSIDA) Sporophyte plant produce spores, which give rise to minute subterranean gametophytes. Each gametophyte bears both female reproductive organ Archegonia and male reproductive organ Antheridia w/c produce both egg and sperm respectively. As a result of fertilization a diploid zygote is formed which develops into sporophyte plant. Sporophyte stage of life cycle is dominant, but haploid gametoplyte stage is still relatively large.EVOLUTION OF LEAFThe leaf is the most important organ of a green plant because of its photosynthetic activity. Leaves are of tow types1. Single veined leaves- Contain only one vein2. Poly veined leaves- Contain two or more veins1- EVOLUTION OF SINGLE-VEINED LEAF

It is assuming that a thorn like out growth emerged on the surface of the naked stem. With an increase in size of the leaf, the vascular tissues were also formed for the supply of water and support to the leaf. Another possibility is that a single veined leaf originated by a reduction in size of a part of the leafless branching system of the primitive vascular plants.2-EVOLUTION OF POLY-VEINED LEAF These are the evolutionary modifications of the forked branching in the primitive plants. The first step in the evolution of this leaf was the restriction of forked branches to a single plane. The branching system become flat. The next step in the evolution was filling the space b/w the branching and the vascular tissues. The leaf so formed looked like the webfoot of a duck.(Fig#9.7-9.8From Text. Book)2-LYCOPSIDA(THE CLUB MOSSES) These plants belong to middle Devonian and carboniferous periods. They were very large trees that formed the earth’s first forests. Only five living genera of this group are present. Two members, selaginella and lycopodium are common in many areas of Pakistan These plants have true branched underground roots. True leaves also present w/c have arisen as simple scale like outgrowth (emergence) from the outer tissues of the stem. Specialized reproductive leaves bearing sporangia on their surfaces, are present, such type of leaves are known as “Sporophylls”. In some members, the sporophylls are collected on a short length of stem and form cone like structure “Strobilus”. The cone is rather club-shaped; hence name “Club-Mosses” for the lycopsids. Gametophytes plant may be homosporous or heterosporous .A) HOMOSPOROUS GAMETOPHYTES Spores produced by sporophyte plant are all alike, and each give rise to a gametophytes that bear both archegonia (female reproductive structure) and antheridia (male reproductive structure)Example Lycopodium (Running pine or ground pine)B) HETEROSPOROUS GAMETOPHYTES Sporophyte (2n) plant produces two types of sporangia, which produced different kinds of spores. One type of sporangium produces very large spores called “Megaspores,” which develop in female gametophytes bearing archegonia.

Other type of sporangium produces small spores called “Microspores, which develop into male gametophytes bearing antheridia. That’s mean sexes are separate in the gametophytes generation (Heterosporous).Example: Selaginella.EVOLUTION OF SEEDSeeds are evolved from primitive spores.STEPS OF EVOLUTION1. PRIMITIVE SPORESAll spores of specie are nearly identical in size, structure and function.2. HETEROSPORES There are many vascular plants that form two kinds of spores, these plants are said to be “Heterosporous” and spores are called “Heterospores.” These spores on germination give rise to two different types of plants.A) MALE SPORE: It produces sperm forming gametophyte plant.B) FEMALE SPORE: It grows into egg forming gametophyte.3. PROTECTION OF HETEROSPORES The two different kinds of spores are formed in two different kinds of sporangia. Various enveloping structures develop in order to protect these spores. Certain fern like plants first developed seed like structures, each of their sporangia, containing one or more female spores, was surrounded by little branch like out growth structure forming “Integument.”4. PERSISTANCE OF FEMALE SPORES Instead of being shed from the sporangium, the female spores are retained and protected inside the integument. The female spore develops into a tiny female gametophyte protected by the integuments.5. FORMATION AND STRUCTURE OF SEED Seed is formed as the result of fertilization of male spore with this protected female spore. Immature seed is called “Ovule.” Ovule is protected by integuments and it contains great quantities of food. Ovule not only protects the female gametophyte from the environment but also provides food for the new off springs that is produced when the seed matures and germinate. The development of seed has given the vascular plants better adaptations to their environment.3. SPHENOPSIDA (THE HORSE TAILS) These plants belong to late Devonian and Carboniferous period. Only one living member “Equisetum” commonly called “Horse-tail” exists today. Ancient sphenopsids were large trees but now most of these are small (Less than one meter).

Coal deposits of today was formed from the dead bodies of those plants. These plants possess true roots, stems and leaves. Stems are hollow and are jointed, whorls of leaves occur at each joint. Secondary growth absent, because modern species do not possess cambium. Spore are born in terminal cones (Strobili) and all are alike (i.e. plants are homosporous) and give rise to small gametophytes that bear both archegonia and antheridia (i.e. the sexes are not separate).4. PTEROPSIDA (THE FERNS) These plants belong to Devonian and Carboneferous Period and then decline in Paleozoid Period. They are very well developed plants having vascular system with true roots, stem and leaves. Leaves are probably arisen from flattened web branched stems. They are large and provide much greater surface area for photosynthesis. Leaves of Ferns are sometimes simple, but more often they are compound, being divided into numerous leaflets. In most modern ferns of temperate regions, the stems are prostrate on or in the soil, and the large leaves are only part normally seen.SPOROPHYTIC STAGE The large leafy plant (fern) is diploid sporophytic phase. Spores are produced in sporangia (Reproductive structure) located in clusters on the underside of some modified leaves “Sporophyll.” Most modern ferns are homosporous i.e. all these spores are alike. Vascular sporophytes can live in drier places and grow bigger.GAMETOPHYTE STAGE After germination, the spores develop into gametophytes that bear both archegonia and antheridia. These gametophytes are tiny (less than one centimeter wide), thin and often more or less heart-shaped. Free-living, non-vascularized gametophytes can survive only in moist places, their sperms are flagellated and water is required for fertilization.Young sporophyte develops directly from the zygote without passing through any protected seed like stage.(LIFE CYCLE OF FERN-TEXT BOOK PAGE # 166 NEW ADDITION)

ALTERNATION OF GENERATION In Kingdom Plantae, life cycle of many plants is completed in two stages or generations known as Gametophyte and Sporophyte. The two generations normally differ from each other in morphology, reproduction and number of chromosomes. The gametophyte is haploid and reproduces sexually by forming the gametes, while the sporophyte is diploid and reproduces a-sexually by forming the spores.

The two generations regularly alternate with each other and therefore, the phenomenon is called “Alternation of generation” (Heteromorphic). In Bryophytes, the main plant itself is the Gametophyte while the sporophyte is reduced. In Tracheophytes, the main plant is “Sporophyte” and the “Gametophyte” is reduced.5. SPERMOSIDA (THE SEED PLANTS) First appeared in late Devonian and became dominant in Carboniferous Period. Gametophyte stage is even more reduced than in the ferns, and non-photosynthetic or free-living. The sperms of most modern species are not independent free-swimming flagellated cells. Young embryo, is enclosed within a seed coat and can remain dormant for long periods. Spermosida can be divided into two main sub-groups, which are as follows:i) Gymnospermsii) AngiospermsI) GYMNOSPERMThese plants have naked seed because ovules are not covered by ovary i.e. fruit is absent.Sub-divisions of Gymnosperms area) Cycadsb) Gnetaec) Ginkgod) ConifersA) CYCADS’ They have arisen from the seed ferns. These plants appeared in “Permian Period” and Mesozoic Period and declined in Cretaceous Period. They possessed large palm like leaves with short height stems. Living species commonly found in tropical regions and also known as “Sago Palms.” Nine living genera with over a hundred species exist today. Cycads and its relatives.B) GINKGOAE Mostly contains extinct species, only one living specie, “the Ginkgo” which is also known as “Maiden Hair Tree.” Ginkgo often planted as lawn tree.E.g: Ginkgo Biloba.C) CONIFERS Most familiar and best-known group of gymnosperms.

Leaves are small evergreen needles or scales with an internal arrangement of tissues. Reproductive organs are cone like modified leaves.E.g: Pinus.PINUSThis plant belongs to Gymnosperms. It includes about 90 species.HABIT AND HABITAT It is distributed world-wide mostly in northern hemisphere. 30 species are found in the Himalayas. Some are reported in the planes of Punjab.MORPHOLOGY The pinus plant belongs to the “Sporophytic Phase.” It is a tall tree, pyramidal in form and gives a conical appearance and therefore commonly grouped under “Conifers.” It is well differentiated into stem, root and leaves.STEMIt is erect, cylindrical, solid and covered with thick, rough and brownish bark. The branches are dimorphic, Branches of unlimited growth or long shoot. Branches of limited growth or dwarf shoot.ROOTSUnderground root system is formed by “Tap Roots” which disappear early and only lateral roots persist later on.LEAVESIt bears two types of leaves (dimorphic condition)a) Scale leavesb) Foliage leavesA) SCALE LEAVES Thin, membranous small scale like structures. Provide protection and do not help in photosynthesis.B) FOLIAGE LEAVES Only develop on dwarf shoots. Number of foliage leaves is fixed for particular specie. Each leave is needle shaped, simple green therefore also known as “Needles.” They have smooth surface and are evergreen and persistent.LIFE CYCLE OF PINUSThe adult plant of Pinus represents the “Sporophytic Phase” of life cycle.The sporophytic plant body of pinus reproduces asexually by means of spores and after passing through “Gametophytic Phase” of the life cycle again produce Sporophytic plant, showing distinct Alternation of Generation.1. SPOROPHYTIC PHASE The sporophytic plants of Pinus are mostly monoecious i.e. male and female cones are found on same plant. Special reproductive organs called “Cones,” developed on it.

A) MALE CONE OR O-STROBILUS The male cones occur in clusters near the end of long branches at the place of dwarf shoot. (Dwarf shoots are replaced by male cone). Each male cone is simple ovoid structure 3-4 cm in length. It has got single centrally located cone axis around which are arranged spirally, many scaly microsporophylls (60-135). Each microsporophyll has an expanded triangular central part and a stalk like base. Each microsporangium, which is born on the lower side bears numerous “Pollen grain mother cells.” When the microsporangium matures, on its lower side a horizontal slit is formed through which numerous Pollen grains are liberated and dispersed by wind. Each pollen grain is winged structure and yellow in colour.B) FEMALE CONE OR O-STROBILUS The female cones are developed laterally in the axis of scale leaves. The female cones are much bigger, woody, dry and hard structure. The young female cone is reddish green structure. Each female cone consists of a central axis to which are attached the “Megasporophyll.” Each megasporophyll on its surface has two ovules. Each ovule is orthosporous and consists of a central mass of tissue, surrounded by a single integument, made up of 3 layers. The integument bears a wide gap, the microphyle. Within the megasporangium, megaspore mother cells are present, which undergoes reduction division to produce a “Megaspore.” Only one megaspore is functional, however the other three degenerate.2. GAMETOPHYTE PHASE The spores are the units of gametophytic phase of life cycle. In case of Pinus the spores are of two types, microspores and megaspores.A) MALE GAMETOPHYTES Microspore is a unit of male gametophyte. Each microspore or pollen grain is a unicellular body, covered with an outer layer, “Exine,” thick and heavily culticularized, while the inner layer, the “Intine” is very thin. The Exine forms the balloon shaped wings on either side, which help in pollination. The microspore is at this, four celled stage (consisting of one generative cell and two prothalial cells and a tube cell).B) FEMALE GAMETOPHYTE The Megaspore is the first cell of female gametophyte. The functional megaspore increases in size and forms a complete cellular female gametophyte, also known as “Endosperm.”

The “Archegonia” are formed towards micropylar side. The cells of the endosperm or Archegonia initial cell divides and forms the central cell. The central cell forms the venter canal cell and a large egg cell.POLLINATIONIn case of Pinus, Pollination is effected by wind (Anemophyllous).FERTILIZATION1. The pollen grains reach the apex of the Archegonium.2. The pollen tube carrying the two male gametes and the tube nuclei comes in contact with the archegonium.3. The tip ruptures, discharging its contents into the egg.4. One of the male gamete fuses with the egg nucleus and unites forming the oospore or zygote.5. The second male gamete along with the tube and tube nuclei disintegrate.PINUS SEED Fertilized ovules get transformed into seeds. Seeds are small elongated and winged.GERMINATION OF SEEDThe seed undergoes into a condition of dormancy when the conditions are favourable, the seed absorbs moisture and the embryo resume growth.STRUCTURE OF OVULE Ovules are female part of flower, form seed after fertilization. Microscopic study of an ovule reveals following structural features of an ovule.1. FUNICLEIt is slender stalk of ovule through which it attaches to the placenta.2. HILUMIt is the point of attachment of the body of the ovule to its funicle.3. RAPHEIn the inverted ovule, the funicle continues beyond the hilum along side of the body of the ovule forming a sort of ridge, which is called the “Raphe.”4. CHALAZAThe distal end of the raphe, which is the junction of integuments and the nucellus is called the “Chalaza.”5. NUCELLUSIt is the main body of ovule.6. INTEGUMENTSNucellus is surrounded by two coats called the “Integuments.”7. MICROPYLEIt is the small opening at the apex of integuments.8. EMBRYO-SACIt is a large, oval cell lying embedded in the nucellus towards the micropyle end. It is the most important part of the ovule as it bears the embryo. It is further developed, and in the mature embryo sac following cells can be seen:A) EGG APPARATUS It is the group of three cells lying towads the micropyle.

One cell of the group is the female gamete, the ovum/egg, and the other two are called “Synergids.” The ovum or egg-cell on fertilization gives the embryo, synergids get disorganized soon after fertilization.B) ANTIPODAL CELLSThis is the group of three cells lying at the opposite end of egg apparatus. These have no definite function.C) DEFINITIVE NUCLEUSIn the middle of the embryo-sac there is a distinct nucleus known as a definitive nucleus, which is the fused product of the two polar nuclei.STRUCTURE OF POLLEN GRAIN Pollen grains are male part of flowers, and are contained in the “Pollen-Sac.” They are very small in size, usually varying from 10 to 200 μm. Microscopic study of a pollen grain shows following features:1. EXINE It is the outer coat of the pollen grain. It is tough, cutinized layer, which is often provided with spinous out growths or markings of different patterns, sometimes smooth. It has one or more weak slits or pores called “Germopores.”2. INTINE It is the inner coat of the pollen grain. It is thin, delicate, cellulose layer lying internal to the exine. During fertilization in time grows to form pollen-tube.3. INTERNAL STRUCTURE Each pollen grain contains a bit of cytoplasm on a nucleus. During germination of pollen grain nucleus further divides to form a “Tube Nucleus,” and a smaller one the “Generative Nucleus.” The generative nucleus soon divides into two male gametes.

Plant Families1- CAESAL PINIOIDEAE/CASIA FAMILY CLASSIFICATION DIVISION : ANGIOSPERMS CLASS : DICOTYLEDON SUBCLASS : POLYPETALAE

SERIES : CALCIFLORAE ORDER : ROSALES FAMILY : LEGUMINOSAE SUB-FAMILY : CAESALPINIOIDEAE OR CAESALPINIACEAE.GENERAL CHARACTERSMajority of these plants are trees or shrubs, about 135 genera and 5800 species are known .VEGETATIVE CHARACTERSROOTUsually, Taproot with nodules and primary, secondary and tertiary divisions.STEMUsually, Climbing stem or erect herbaceous or woody, Some plants show xerophytic character.LEAVESUsually, Compound leaves bipinnate, stipulate.INFLORESCENCEUsually, Racemose.FLORAL CHARACTERUsually, Complete, bisexual, perigynous, zygomorphic, pentamerous.CALYX5 sepals, polysepalous, imbricate or valvate, Green in colour.COROLLA5 petals, poly petalous, imbricate aestivation.ANDROECIUMUsually, 10 stamens, polyanderous, exerted, extrose.GYNOECIUMUsually Monocarpillary, perigynous, placentational marginal, unilocular with many ovules.FLORAL FORMULA+ , Q , K(5) , C(5) , A10 , G1/POLLINATIONUsually, Cross pollination by insects (entomophilly)SEEDSUsually, Both endospermic and non-endospermic.FRUITLegume pod.ECONOMICAL IMPORTANCEMEDICINAL PLANS Amaltas Kachnar Tamarindus Indica Panwar. e.t.c.ORNAMENTALS Parkinsonia Gul-e-mohar Cacia sophera

DYES AND STAININGHaemotoxylin is obtained from haemotoxylon campechianom.EDIBLE FRUITLomentum (Imli)FIBERSuitable fiber for paper making is obtained from parkinsonia Aculeata.FAMILIAR PLANTSBotanical name…………Common Name……………Local Names1-Tamarindus indica………Tamarind……………..Imli2-Cassia fistula…………Amaltus.3-Bauninia verigata………Camel’s foot………….Kachnar4-Poinciana regia………..Flame of Forest ………Gul-e-Mohar5-Parkinosia roxburgai……VilayatiKikarFLORAL DIAGRAM(From Book)2 MIMOSACEAEALTERNATE NAMEIt is also known as “Acacia family”.CLASSIFICATION DIVISION : ANGIOSPERMS CLASS : DICOTYLEDON SUBCLASS: POLYPETALAE SERIES : CALCIFLORAE ORDER : ROSALES FAMILY : LEGUMINOSAE SUBFAMILY : MIMOSACEAE / ACACIAGENERAL CHARACTERSIt is the smallest group among the 3 groups of family legume. It contains about 40 genera and 1450 species.HABITATMostly plants are distributed in tropical and subtropical regions. Great variation inhabit, usually these trees are perinial or binnial shrubs, some are herbs and climbing.VEGETATIVE CHARACTERS1. ROOTUsually, Tap root with side branches, nodules are present.2. STEMUsually, Erect and woody stem, rarely herbacious, tannin and gums may also present.3. LEAVESUsually, Compound, bipinnate, stipule are modified into spines. In many plants leaves show sleeping movement or after having a shock.INFLORESCENCEMostly, racemose.FLORAL CHARACTERSUsually, Complete, bisexual actinomorphic, perigynous, pentamerous.

1. CALYXUsually, 5 sepals, gamosepalous, valvate.2. COROLLAUsually, 5 petals, polypetalous, valvate aestivation, small size.3. ANDROCEIUMUsually, numerous stamens, exerted, extrose, basifixed anther.4. GYNOECIUMUsually, Monocarpillary, perigynous, unilocular, placentation marginal, many ovules in locule.POLLINATIONUsually, cross pollination by insects (entomophilly).SEEDSUsually, Non-endospermic or with very little endosperm.FRUITUsually, It is called legume.FLORAL FORMULA+ ,Q , K(5) , C(5) , Aα , G1/ECONOMICAL IMPORTANCE1.WOOD YIELDING PLANTSe.g-prosopis Acacia species Albizzia Xyliaet2. ORNAMENTALSe.g-Mimosa pudica (chuimoi) Austratian Acacia Neptunia3. FOODERFrom leaves of prosopis, Acacia Dicrostachys e.t.c.4. SOAP POPSAcacia concinna pods have (soponim), a substance can be used as Soap.5. CATECHU (KATHA)Piece of hard wood6. MEDICINAL USE Katha Siah Kanta Entada Acacia senegal7. GUMS & DYES Katha Safed Babul Sada Babul

IMPORTANT FAMILY MEMBERSBOTANICAL NAME…………..COMMON NAME…………….LOCAL NAME1-Acacia nilotica…………….Gum tree……………..Bauble, Kikar2-Albizzia lebbek…………….Siris3-Mimosa pudica……………..Touch-me-not…………..Chhui mui4-Prosopis glandulosa…………Prosopis……………..Devi5-Acacia catechu……………..Katha plantFLORAL DIAGRAM(FROM BOOK)3- ROSACEAECLASSIFICATION Division Class Subclass Series Order Family: Rosaceae / Rose family.GENERAL CHARACTERSIt has about 100 genera and 2000 species.HABITATThese plants are found growing all over the world 213 species of about 29 genera are reported from Pakistan.VEGETATIVE CHARACTERS1. ROOTUsually, Tap root with its usual branching.2. STEMUsually, Green herbaceous, cylindrical, small spines are also present.3. LEAVESUsually, Simple leaves with or without petiole, Opposite or alternate.INFLORSCENCEUsually RacemoseFLORAL CHARACTERSUsually, Complete, bisexual, actinomorphic, perigynous, pentamerous.1. CALYXUsually, Sometime epicalyx may also be present, of variable number, 5 sepals are present, Gamosepalous, green, pubescent.2. COROLLAUsually, 5 petals or multiple of 5 petals, polypetalous, aestivation, imbricate, shape-rosaceous, full of colour.3. ANDROCEIUMUsually, Nomerous stamen,ditheous, anther, enerted, extrose, dorsi fixed.4. GYNOECIUMUsually, Monocarpillary or multiple capillary with formation of a single compound pistil. Ovary perigynous, unilocular two or more ovules are present, placentation axile when the carpels are many and syncarpousFLORAL FORMULA

+ , Q , K(5) , C(α) , Ax , G1/ (2-5) or xECONOMICAL IMPORTANCEFRUITEconomical importance of this family is great in providing the pleasure and welfare of mankind. Plants of many famous fruits belong to this family for e.g. Apple, pear, peach, e.t.c. Perhaps they rank 3rd in commercial importance in the temperate, zone among the families of flowering plants.ORNAMENTALSA large no. of ornamental plants of this family are grown in parks and gardens the most widely cultivated plant for this purpose is Rosa. Many others genera are also grown for their beautiful flowers in homes and gardens.OTHERSBranches of crataegus and cotoneaster provide excellent walking stick and wood. The wood of pyruspastia is used for making tobacco pipes. In Asian countries rose petals are used in making Gul Khand and are also used in extraction of an essential oil, Rose oil, used as perfume or may be used as eye cleaner in certain diseases.FAMILIAR PLANTSBOTANICAL NAME……………….COMMON NAME…………..LOCAL NAMEMalva silvestis……………………….Apple………………..SebPyrus pyrifolia……………………….Pear…………………NashpatiPrunus amygdalus………………………Almond………………..BadamRosa indica…………………………..Rose………………….GulabPrunus persica………………………..Peach…………………AruFLORAL DIAGRAM(FROM BOOK)4-SOLANACEAEALTERNATE NAMENight shade or Potato familyHABIT AND HABITAT It is widely distributed in temperate region and very abundant in tropical countries. The plants are usually herbs or climbing vines but may be shrub.VEGETATIVE CHARACTERS1-ROOTTap root and branched2-STEMHerbacious, erect or underground(Potato)3-LEAFAlternate in vegetative and opposite in floral regionFLORAL CHARACTERSINFLORESCENCECyme sometimes helicoids1-FLOWERPentamerous, Bisexual, Regular, Actinomorphic, Hypogynous.2-CALYXFive, united sepals

3-COROLLAFive petals, united, valvate aestivation4-ANDROCIEUMFive stamens, Inserted on Corolla5-GYNOECIUMBicarpellary, Syncarpous (Carpels fused), Placentaion axile.6-FRUITCapsule Berry or Xanthium.7-SEEDMinute with abundant endosperm.FLORAL FORMULA+ , O , K(5) , A5, C(5) ,ECONOMIC IMPORTANCEMembers of this family provide drugs and food. Some plants are poisonous and other are ornamental. This family is of great economic importance as it provides food, fodder, drugs and ornamentals.1-FOODER Solanum tuberosum (Potato) Lycopersicum esculentum (Tomato) Solanum melongena (Brinjal)2-CONDIMENTS Fruit of capsicum Capsicum frutenscens3-EDIBLE FRUIT Physalis (Cherry or Rasbhari)4-DRUG YIELDING Atropa belladonna (atropine) Dotura (Daturine) Used in severe cold and in eye diseases. Sap of hanbane is used in dilating the pupils, white cherry is used an nerve tonic.5-ORNAMENTAL Cultivated in gardens Petunaia Nicotiana Cestrum Schizanthus Brunfelsia solanum6-CIGARETTE MAKING Nicotiania tobacum (Tobacco)IMPORTANT FAMILY MEMBERSBOT-NAME……………………COMMON NAME…………………….LOC-NAME1-Solanum Tuberosum………………Potato…………………………Aaloo2-Solanum Melongena………………Bringal………………………..Bengan3-Lycoperscum Escalentum………….Tomato…………………………Temater

4-Capsicum Annum…………………Red-Pepper……………………..Lal-mirch5-Petunia Alba…………………..Petunia6-Solanum Nigrum…………………Black Night shade7-Datura Alba……………………Thorn apple8-Nicotiana Tobaccum……………..Tobacco………………………..Tambako9-Atropa Belladonna………………Deadly night shade10-Cestrum nocturnum……………..Lady of night…………………..Raat ki RaniFLORAL DIAGRAMFROM TEXT BOOK (BIO-XI FAMILY SOLANACEAE )5-FABACEAEALTERNATE NAMEPapilionaceae or Pea familyHABIT AND HABITATPlants are herbs, shrubs or trees. Climbers, aquatic plants or xerophytes. World wide distributed.VEGETATIVE CHARACTERS1-ROOTSTap root, branched bearing tubercle containing nitrogen fixing bacteria.2- STEMHerbecious or woodi, erect or climber.3-LEAFSimple or commonly compound alternate, stipulateFLORAL CHARACTERS1- INFLORESCENCERacemose, rarely solitary.2- FLOWERBisexual, irregular, zygomorphic, hypogynous.3- CALYXFive sepals, united4- COROLLA Five petals, usually free. Corolla is papilionaceous (Butterfly shaped). In this form the petals are 5, one of them is usually large and clawed. This petal is called standard or “Vexillum” The two lateral ones, which are free are called as “Wings” and two anterior inner most fuse to form a boat shaped structure called the “Keel” or “Carina”.5- ANDROCIEUMStamens (9) +1 i.e 9 fuse to form a round sheath around the pistil while tenth is free.6-GYNOECIUMMonocarpellary, ovary unilocular, ovule numerous on marginal placenta.7-FRUITLegume or pod.8-SEEDEX-albuminous.FLORAL FORMULA+ , Q , K(5) , C 1+2+(2) , A(9)+1 , G1

ECONOMIC IMPORTANCEThe family is of considerable importance, as a source of high protein food, oil and forage as well as for ornamental purposes. Chief importance lies in the pulses, belonging to this family. All types of pulses (Dalls) are actually the seeds of this family which are rich in protein.1- FOOD & FORAGE Cicer arietinum (Gram) Pisum sativum (Pea) Lens esculanta (Masure) Phaseolus aureus (Mung) Phaseolus mung (Urad/Mash) Phaseolus vulgaris (kidney bean/Lobia) Medicago sativa alfalfa (Lusan) Vicia Melilotus & Trifolium2- FURNITURE & BUILDING PURPOSE Butea Dilburgia3- OIL EXTRACTIONArachis hypogea (Peanut/Moongphali)4- DYES Indigofera tinctoria (Neel) Butea monosperma (Yellow dye)5-MEDICINAL PURPOSE Glycyrrhiza glabra (Cough & cold treatment) Clitoria termatea (Snake bite treatment)6- ORNAMENTAL PLANTS Lathyrus Lupinus Clitoria Butea Abrus precatorious, used by jewellars as weights called “Ratti”.IMPORTANT FAMILY MEMBERSBOT-NAME……………….COMMON NAME………………..LOCAL-NAME1- Lathyrus Odoratus………..Sweet pea………………….Matter2- Arachis Hypogea………….Peanut…………………….Moongphali3- Cicer Arietinum………….Gram………………………Channa4- Dalbergia Sisso………….Red-wood…………………..Shesham5- Pisum Sativum……………Edible pea6- Sesbania aegyptica……….SesbaniaFLORAL DIAGRAMFROM TEXT BOOK BIOLOGY-XI Pg # 1916-POACEAE

ALTERNATE NAMEGRAMINAE/ GRASS FAMILYHABIT AND HABITAT The species are most numerous in the tropics but they are also abundant in temperate region. This family is monocot (one cotyledon in seed) Mostly annual or perennial herbs or shrubs.VEGETATIVE CHARACTERS1- ROOTSAdventitious, fibrous or fascicled.2- STEMCylindrical, Conspicuous nodes and hollow, although solid stems are also found as sugar cane.3- LEAFLegulate, alternate leaf sheath mostly open sessile, lamina narrow and ribbon shaped.FLORAL CHARACTERS1- INFLORESCENCECompound spikes.2- FLOWERSessile, bracteate, incomplete, bisexual or unisexual and zygomorphic.3- PERIANTHIt is combined structure instead of calyx and corolla. Number 2 or 3 membranous scales called “ Lodicules”4- ANDROECIUMUsually 3 stamens, filaments long, free anther versatile.5- GYNOECIUMTricarpellary, syncarpous though only one is functional, unilocular, single ovule, style short 2-3, stigma feather like.6- FRUITGrain or coryposis.7- SEEDEndospermic, monocotyledonous.FLORAL FORMULA+ or O , O or O or O , P2 (lodicules) , A3 or 0 , G1 or 0ECONOMIC IMPORTANCEThe family poaceae has great importance than any other family of flowering plants.1- FODDER AND FOOD STUFF Triticum indicum Avena sativa Zea mays Oryza sativa Hordeum vulgare Pennisetum typhoideum2- SUGAR MAKING

Saccharum officinarum (sugar cane)3-PAPER MANUFACTURING Certain species of Grasses4- VEGETABLES & SOUP DISH Sugar cane Bamboo-shootsIMPORTANT FAMILY MEMBERSBOT-NAME…………………………COM-NAME…………………….LOC-NAMETriticum Indicum……………………..Wheat……………………….GandumAvena Sativa…………………………OatsZea Mays…………………………….Indian corn………………….MakaiOryza Sativa…………………………Rice………………………..ChawalSaccharum Officinarum…………………Sugar cane…………………..GannaHordeum Vulgare………………………Barly……………………….JooPennisetum Typhoideum…………………BajraBambusa Arundinacea…………………..Bamboo………………………BannsCymbopogon Jawarancuza……………………………………………..Lemon GrassCynodon dactylon…………………………………………………..Lawn GrassFLORAL DIAGRAMFROM TEXT BOOK BIOLOGY-XI Pg#196)DOUBLE FERTILIZATION After pollination, the tube nucleus of the pollen grain forms pollen tube, while generative nucleus divides into two male (sperm) gametes. When pollen tube reaches the embryo sac through micropyle, one of the male gametes fuses w/t egg cell and forms “oospore (zygote)”,it develops into seed. Another male gamete fuses with definitive nucleus and forms “Endospermic nucleus”, w/c develop into endosperm of seed or food storage tissue of seed. Because two times fertilization occurs so it is called “Double fertilization”.THE FLOWERSThe flower is a modified shoot and meant for sexual reproduction. It is collection of four different kinds of floral members, arranged in four separate whorls. The upper two whorls are essential or reproductive whorls whereas lower two are helping or accessory whorls. The flower is born on an axis which consists of two parts the pedicel or stalk of flower and the thalamus is swollen end of the axis on which the floral leaves are inserted. The floral whorls are arranged on the thalamus in a particular order one just above the other. These four whorls are as follows.CALYXIt is the first or lower most whorl of the flower, the calyx is generally green is colour. Each member of calyx is known as sepal. Sometimes sepals become coloured called petaloid. Such as in gold mohur. The calyx is non essential or accessory part of flower.FUNCTIONS1- Protection of floral bud

2- Assimilation when green in colour3- Attraction when coloured and showy4- Modified into papus which helps in dispersalCOROLLAIt is the second non essential floral whorl of flower. It is brightly colored. Each member of its known as petal. However there is no differentiation of calyx and corolla in some flowers. It is called perianth.FUNCTIONS1- The corolla attracts insects and hence help in pollination.2- It encloses stamens and carpels.3- It protect the stamens and carpels from external heat rain and insects attack.ANDROCIEUMIt is the third essential floral whorl and each member of it is known as stamen. The stamen is a male reproductive body and consists of filament, anther and connective. The anther bears four chambers of pollen sacs, each chamber is filled with granular mass of small cells called pollen grains. Each pollen grain consists of two walls, the outer exine and inner intine.FUNCTIONSIt is the male reproductive body and hence possess male gametes which take part in reproduction.GYNOECIUMIt is the fourth essential floral whorl and its component parts are called carpals. The carpel is a female reproductive body, it may be one or more than one, and may be united or free. Each carpel consists of stigma, style and ovary. The stigma is terminal end which receives the pollen grain. It may be smooth or hairy and becomes sticky on maturity, The style is slender projection of ovary, It helps in pollination and later on dries up. The ovary is swollen basal portion, which encloses minute egg like bodies called ovules. The ovule possess egg cells.FUNCTIONSThe gynoecium is a female reproductive body. It possess the egg cells which take parts in reproduction.AESTIVATIONIt is the arrangement of floral whorls i.e. the sepals or petals in a floral bud, it is of following types:(A) VALVATEThe members of a whorl lie close to each other and do not overlap e .g Calatropis.(B) TWISTEDOne margin of a floral whorl overlaps that of the next one. It may be clockwise or anti clockwise e.g. China rose.(C)VEXILLARYWhen petals are five, two internal are overlaped on both margins by two petals, these two are overlaped by a single largest posterior petal e.g. Pea bean etc.(D)IMBRICATEWhen one of the sepal or petal is internal and other external and each or remaining one is overlaped on one margin and it overlaps the next one on other

margin e.g Gold mohur .A. Velvate.B TwistedC. VexillaryD. Imtricate.INSERTION OF FLORAL LEAVES ON THE THALAMUSThe floral leaves are inserted on the thalamus in a particular order, it is of following types:(A) HYPOGYNOUSIn some flowers the thalamus is convex or conical and ovary occupies the highest position on it. However other floral whorls are inserted below the ovary, such flower is known as hypogynous and ovary as superior. E.g. Mustard.(B ) PERIGYNOUSIn certain flowers thalamus forms a flattened circular disc due to the fact that sises of thalamus grows up to the same level. The apex of thalamus is in the middle of the disc at which gynoecium develops, whereas at the rim or margin sepals, petals and androecium are inserted. They are round about it and hence are called perigynous, such as in pea. Sometimes the apex of thalamus grows up in conical shape as in raspberry. Whereas in some cases the calyx forms a cup shaped structure called calyx tube such as in wild rose.(C) EPIGYNOUSIn some flowers the concave receptacle surrounds the ovary and is fused with it. The sepals, petals and stamens apparently arise from the tip of the ovary such ovary is said to be inferior. E.g. Sunflower, apple, guava, pear etc.IMPORTANT TERMS TO DESCRIBE A FLOWERCOMPLETE: When all the four floral whorls are present.INCOMPLETE: When any of the whorl is absents.BISEXUAL: The stamen and carpel both are present.UNISEXUAL: The flower possess either stamen or carpel.STAMINATE: Only stamens are present (male).PISTILATE: When flower possess only carpels (female).NEUTER: The stamens and carpels both are absent.SYMMETRY+ACTINOMORPHICWhen a flower can be divided into two equal halves by any vertical section passing through centre.+ ZYGOMORPHICWhen it can be divided into two similar halves by only one vertical section.+ IRREGULARThe flower can not be divided into two similar halves by any vertical plane.COHESION OF STAMEN+ MONOADELPHOUSWhen filaments are united in a bundle and anthers are free e.g. China rose.+ DIADELPHOUSThe filaments are united into two bundles and anthers are free e.g. Pea.+ POLYADELPHOUSThe filaments are united into more than two bundles and anthers are free.

+ SYNGENECIOUSThe anthers are united together and filaments are free e.g. Sunflower.ADHESION OF STAMENS+ EPIPETALOUSThe stamens adhere to corolla, wholly or partially by their filaments.+ GYNANDROUSWhen stamens adhere to carpels e.g. Calatropis.LENGTH OF STAMENS+DIDYNAMOUSThe stamens are four, two of them short and two long e.g. Nerium.+TETRADYNAMOUSThe stamens are six but two short and four long e.g. mustard.GYNOECIUM+ MONOCARPELLARYThe pistil consists of only one carpel, it is also known as simple pistil e.g. Pea, Bean+ POLYCARPELLARYThe pistil consists of two or more carpels, it is also known as compound pistil e.g. Rose.+ SYNCARPOUSThe carpels are united into one ovary e.g. Mustard.STIGMA

+ CAPITATEWhen stigma is rounded and knob like. Bi, tri or Multified: when stigma is branched into two , three or many.+ FEATHERYWhen stigma is feather like.+ FLATTENEDWhen sitgma is flat.+ POINTEDWhen stigma is pointed.+ LINEARWhen it is long and narrow.STYLE+ TERMINALWhen style arise from top of ovary; such as in Mustard.+ GYNOBASICWhen it arise between the lobes of the ovary from its base;such as in Salvia.+ PEDICILLATEWhen flower is born on a stalk or pedicel. (STALKED)+ SESSILEWhen stalk is absent+ BRACTEATEWhen flower is developed in the axil of a bract+ EBRACTEATEWhen bract is absent.+ DIMEROUS

When each floral whorl has two floral leaves (Dicot)+ TRIMEROUSWhen floral whorl has three floral leaves (Monocot)+ TETRAMEROUSWhen each floral whorl has four floral leaves; and so the pentamerous Dicots)CALYX+ PETALOIDThe calyx having other then green colour.+ CAMPANULATESepals fused to form bell shaped structure.+ POLYSEPALOUSWhen sepals are free from one another.+ GAMOSEPALOUSWhen sepals are fused or united with one another.PETALS+SEPALOIDThe petals are green in colour.+CRUCIFORMPetals are arranged in form of a cross.+POLYPETALOUSWhen petals are free from one another.+GAMOPETALOUSWhen petals are united with one another.+PERIANTHWhen calyx and corolla can not be distinguished with one other due to similar shape and colour.PERIANTH+SEPALOIDWhen perianth leaves are green.+POLYPHYLLOUSWhen perianth leaves are free from one another.+GAMOPHYLLOUSWhen perianth leaves are fused.FLORAL FORMULAThe floral formula is represented by various symlols. The symbols used in floral formula are as follows.SYMMETRY OF THE FLOWERZygomorphic = +Actinomorphic = OSEXUALITY Bisexual = Q+ Unisexual (male) Unisexual (female) Neuter =PERIANTH Perianth = P Polyphyllous = Pn n=number of perianth leaves.

Gamophyllous = (n) “ “ “CALYX Epicalyx = Epi K Petals = C Calyx = K Polypetalous = Cn, Polysepalous = Kn, n= number Gamopetalous = C(n) Gamosepalous = K (n) of sepalsANDROECIUM Androecium = A Androecium free = An n= number of stamens Androecium United = A (n) Epipetalous = C-AGYNOECIUM Gynoecium = G Apocarpous = Gn Syncarpous = G (n) Ovary inferior = G n= number of carpels Ovary Superior = GFLORAL DIAGRAMThe features of flower in flora formula are represented by symbols, while in floral diagram by the diagram of its various floral leaves alongwith actual number and position.MOTHER AXIS: It is represented by a Dot above the floral diagram. It actually shows the position how a flower is born. The position of it can be seen from upperside. It may be between two adjacent sepals or a single sepal.PLACENTATIONIt is the arrangement of placenta which are cushion like ridges in the ovary, The placenta bear ovules. In simple ovary placentaion is marginal, whereas in compound ovary it may be parietal, axile, free central, basal and superficial.(A) MARGINALIn a simple ovary or monocarpellary pistil, the ovules are arranged along the fused margins, these margins forms a cushion like tissue called placenta along the ventral suture on the inner surface of ovary wall e.g. Pea, Gram, Bean, etc.(B) PARIETALIn a compound syncarpous and unilocular ovary, the fused margins of the carpals swells up to form placentas, to which ovules are attached. The placentas lie along the wall of ovary and their number indicates the number of carpels forming ovary e.g. cucumber, Melon; etc.(C) AXILEIn a polycarpellary syncarpous pistil and multilocular ovary, each carpel is folded along its mid-rib and meets in the centre of the ovary. The ovules are

attached to this central axis e.g. Tomato, China rose, etc.(D) FREE CENTRALIn a compound and unilocular ovary the ovules are situated all around the central axis, which arise from the thalamus and not fused with the margins of the carpels. However in some plants the axile placentation becomes free central due to breaking down of septa e.g. Pink (Diantus)(E) BASALIn a unilocular ovary the placentas develops directly on the thalamus and bears single ovule at the base of ovary e.g. Sunflower, Cosmos etc.(F) SUPERFICIALIn a multilocular ovary, the ovules are not on the margins of the carpels; but over the whole inner surface of the partition walls e.g. Waterlily.TYPES OF PLACENTATION1.FOR SIMPLE OVARYOnly one type, MARGINAL.2.FOR COMPOUND OVARYI- ExileII- CentralIII- ParietalIV- BasalV- Superficial.1. MARGINAL PLACENTATIONIn marginal placentation, the ovary is one chambered and the placenta develops along the junction of the two margins of the carpel, called the ventral suture.EXAMPLESPea, wild pea, gram, gold mohr, and cassia are common examples.2. AXILE PLACENTATIONIn the axile placentation the ovary is two to many chambered and the placenta bearing the ovules develop from the central axis e.g. Potato, Tomato, Petunia, China rose etc.3. CENTRAL PLACENTATIONIn this case the septa in the young ovary soon break down so that the ovary becomes one-chambered and the placenta develops all round the central axis e.g. Dianthus, Saponaria etc.4. PARIETAL PLACENTATIONThe ovary is one chambered and placenta develops on the inner wall of the ovary e.g. papaw, orchids etc.5. BASAL PLACENTATIONThe ovary is unilocular and placenta develops directly on the thalamus e.g. sunflower, cosmos etc.6. SUPERFICIAL PLACENTATIONThe ovary is multilocular, carpels are numerous and placenta develops all round the inner surface of the partition walls as in waterlily.INFLORESCENCEThe branch system of the floral region bearing a group of flowers is called INFLORESCENCE. The term inflorescence refers to the arrangement of flowers on plant.

TYPES OF INFLORESCENCEThe flowers may be solitary or grouped into clusters, Such clusters vary in shape and arrangement. On the basis of arrangement of flowers, inflorescence is classified into1-RECEMOSE1- In this case, the main axis of inflorescence does not end in a flower.2- Main axis continues to grow and gives off flowers laterally.3- The lower or outer flowers are always older and open earlier than the upper or inner ones.4- Order of opening of flowers is called centripetal.EXAMPLESMustard, Gold mohr, Mulberry, birch etc.KINDS OF RECEMOSE INFLORESCENCERecemose inflorescence has following main types on the basis of nature and shape of the peduncle:I- PEDUNCLE ELONGATEDIt is further subdivided into following types;1. RECEMEThe main axis in this case is elongated and it bears laterally a number of flowers which are all stalk e.g. radish, mustard, dwarf gold mohur etc.2. SPIKEIn this case the flowers are sessile e.g. Adhatoda, Achyrnthes etc.3. CATKINThis is a spike with a long and pendulous axis which bears unisexual flowers e.g. Musberry, Acalypha, Birch and Oak etc.4. SPADIXThis is also a spike with a fleshy axis which is enclosed by one or more large bracts called spathes e.g. Banana, Palms etc.II- PEDUNCLE SHORTENEDIt is further divided into following types;1. CORYMBHere the main axis is comparatively short, and the lower flowers have much longer stalk than the upper ones. Hence all the flowers are brought more or less to the same level e.g. candytuft, wall flowers etc.2. UMBELHere the primary axis is short and it bears at its tips a group of flowers which have pedicles of more or less equal length so that the flowers are seen to spread out from a common point. In the umbel there is always a whorl of bracts forming an involucre, and each flower develops from the axil of a bract, e.g. Carrycumin, Coriander etc.III- PEDUNCLE FLATTENEDThe best example is seen in sunflower family, here the inflorescence is called the head as the capitulum.HEAD OR CAPITULUM1. A dense cluster of sessile or sub-sessile flowers, on a compound receptacle is called capitulum.2. Main axis is almost flat, bearing sessile flowers.3. Outer flowers are older and open earlier.

4. The florets are commonly of two typesI- RAY FLORETSII- DESC FLORETSEXAMPLESCapitulum is characteristic feature of sunflower family e.g. sunflower, marigold; zinnia, cosmos etc.IV- SPIKELET INFLORESCENCEIt is a kind of racemose inflorescence. There are three bracts at its base called glumes. The lower two without flowers are called empty glumes. The third glume has flower in its axil and called Lemma. Just opposite to lemma, there is small bractcole called Palea. Flowers are covered by their respective lemma and palea. This type of inflorescence is characteristic feature of family Poaceae (Grass Family).2-CYMOSE1- Here the main axis ends in a flower and similarly the lateral axis also ends in a flower.2- The growth of each axis is checked due to presence of flower on its tip.3- The terminal flowers are always older and open earlier than the lateral ones.4- The order of opening of flowers is centrifugal.EXAMPLESJasmine, Teak, Night Jasmine, Ixora.KIND OF CYMOSE INFLORESCENCEI- UNIPAROUS (MONOCHASIAL) CYMEMain axis soon ends into a flower and produces only one lateral branch at a time ending in a flower. The succeeding lateral branches again follow the same mode of producing flowers. If the succeeding branches are produced on alternate side, it is called Scorpiold cyme (cotton, forget-me-not). Whereas, if the succeeding branches are produced on same side, it is called Helicoid (sundew).II- BIPAROUS (DICHASIAL) CYMEMain axis soon terminate into a flower and produces two flowers. This mode is followed by each succeeding flowers (Pink, Night- Jasmine).POLLINATIONIt is the process of transference of pollen grains to the stigma of the flower.TYPES OF POLLINATIONPollination is of two types.1- Self pollination or Autogamy.2- Cross Pollination or Allogamy.(A)SELF POLLINATIONIt is the transfer of pollen grains from the anther of a flower to the stigma of the same flower.METHODS OF SELF POLLINATIONIn self pollination, only one flower is concerned to produce the offspring. Irrespective whether the flower is unisexual or bisexual self pollination can take place by two methodsI-HOMOGAMYIn homogamy the anther and the stigma of a unisexual flower mature at the same time. In rare cases it may takes place by insects or wind.

II- CLEISTOGAMYIn cleistogamy the flower never open. They remain closed and the pollination takes place in the closed flower such as in pansy (viola), balsam (impatiens), oxalis, etc.B)CROSS POLLINATIONIt is transfer of pollen grain from the flower of one plant to the stigma of flower of another plant of the same species.METHODS OF CROSS POLLINATIONIt takes place by external agencies. These agents are insects, animals, birds, wind and water.I- ENTOMYPHILYThe pollination takes place by insects. It is of general occurrence in plants.II ANEMOPHILYThe pollination is brought about by wind.III HYDROPHILYThe pollination takes place in aquatic plants particularly the submerged ones, through the medium of water e.g. Hydrilla and vallisneriaIV ZOOPHILYThe pollination is carried out by birds, squirrels, snails etc. Examples are Bombax and Erythrina.

Phylum Porifera (Sponges)MAIN CHARACTERISTICS Animals of this phylum show following important characters.NATUREMost simple multicellular organisms. From evolutionary point of view they occupy a position between protozoa and true metazoaHABIT AND HABITAT Mostly marine but few in fresh water habitat. They are sessile, living attached to rocks, coral and other hard surfacesSHAPE AND STRUCTURE Their shape may be cylindrical, branching, globular, flat, bell shaped or cup shaped. Some are dull in colour and most are brightly coloured. The body is perforated by pores and canals.

MICROSCOPIC STRUCTUREMost of sponges contain following types of cell:(A) PINACOCYTESForming the epidermis.(B) POROCYTESForm pores of the body wall(C) CHOANOCYTESThese are flagellated cells, form the internal lining of the body. These cells are strikingly similar to the choano flagellates. Much of the body is composed of jelly like matrix containing a skeleton made of Protein, CaCO3 or silica. Sponges are organized on cellular level, instead of a single cell carring on all the life activities. Sponges show cellular differentiation but little or no coordination of cells to form tissues. They usually have an endoskeleton of separate spicules. They do not posses a head, an interior end, a mouth or gut cavity. They are sedentary organisms ranging in size from 1 to 200cm.DIGESTIONDigestion takes place with in the cell. (Intracellular)PROCESS OF FEEDING, EXCRETION AND RESPIRATION Sponges feed by filtering out bacteria and fine particles of organic matter from water. The flagella of “Choanocytes” beat and create a current of water. The water current also helps in respiration, removal of waste products and dispersal of gametes.REPRODUCTION Reproduction is of both type asexual and sexual Asexual reproduction is by means of “Buds” and “Gemmules formation”. Sexual reproduction is by means of sperm and ova. All sponges appear to be diploid and have the usual metazoan process of “Oogenesis” and “Spermatogenesis”. The eggs retained just beneath the choanocytes where they are fertilized by sperm from another sponge brought in with the current of water. Fertilization is internal.LARVA After cleavage, the larva escape from the parent to the open sea as a free swimming “Amphiblastula larva”. It finally becomes attached to the bottom by its anterior end. Reproduction is also by fragmentation.BODY CAVITYBody cavity is known as “Spongocoel”.EXAMPLESCommon examples are

1. Sycon2. Euplectella3. Euspongia

Phylum Cnidaria (Coelenterata)MAIN CHARACTERS HABIT AND HABITATThey are aquatic animals, mostly marine and few fresh water forms. They are sedentary or free swimming and solitary or colonialSTRUCTURE The cnidaria are metazoa having the simplest type of body wall consisting of two layers. The outer epidermis and the inner gastrodermis which lines the body cavity. In between the two layers lies the mesogloa, non-cellular jelly secreted by them. Cnidarians, due to their two layers body wall are termed as diploblastic animals. All other metazons possesses a third layer called mesoderm in their body wall, laying in between the epidermis and gastrodermis (Endoderm) and are therefore called Triploblastic animals. They have radially symmetrical body plan organized as a hollow sac. The mouth is surrounded by a circle of tentacles bearing cnidoblasts stinging cells containing nematocysts. They have central digestive cavity connected to the outside by mouth.STRUCTURAL TYPESThe Cnidarians are radially symmetrical and occur in two types of forms.(a) The polyp(b) The Medusa(A) POLYPThe polyp like Cnidarian for example sea anemone has a cylindrical body with a mouth directed upwards and surrounded by tentacles. The basal surface of the body is attached to the substratum.(B) MEDUSAThe medusa like Cnidarians jelly fish are umbrella like in appearance. Their oral surface, bearing the mouth is directed downwards. Whereas the aboral

surface is directed upward. The medusoid Cnidarians are usually free swimming.PROCESS OF FEEDING AND DEFENCE The Cnidarians feed mostly on animal diet. The food is digested in the gut and the waste products are expelled through the mouth. The Cnidarians so named, because they possess cnidoblasts bearing nematocysts which help in feeding and defence.REPRODUCTIONThe Cnidarians reproduce by asexual as well as sexual methods. Polypoid Cnidarians possess a remarkable ability to regenerate.(A) REGENERATIONIf the oral part of the body is lost. The remaining part regenerates the new mouth and the whole of tentacles.(B) ASEXUAL REPRODUCTIONA sexual reproduction takes place by Budding.(C) SEXUAL REPRODUCTION The sexual reproduction takes place through male or female gametes which are usually produced by different parents. The gametes develop in the interstitial cells and aggregate in gonads which are located either in the epidermis or in the gastodermis. The fertilized egg gives rise to “Planula Larva”CLASSIFICATION OF CNIDARIA (COELENTERATA)The Phylum Cnidaria is divided into three classes:1. Hydrozoa2. Scyphozoa3. Anthozoa1. HYDROZOAAs the most primitive class of the Cnidarians, Hydrozoa is thought by some evolutionists to have given rise to both other classes. They show following characteristic features: They are mainly marine, but some are fresh water species Many species have both polyp and medusaFor e.g:Hydra, Obelia and Physalia2. SCYPHOZOA Most of animals of this class are commonly called “Jelly Fish”. They are semitransparent and are of various colours. Most are of marine habitat.For e.g:Aurelia and Cyanea (largest Jelly Fish)3. ANTHOZOA These animals are mostly marine. Solitary or colonial Polyp forms are present. Medusa stage is absent.

Gastrovascular cavity is divided into chambers, increase area for digestion.For e.g:Sea-anemones and Corals etc

Phylum Platyhelminthes (Flat worms)MAIN CHARACTERS HABIT AND HABITATAnimals are mostly Parasitic in habitat and found in other higher animals. But some animals are also free living.NATUREThey are triploblastic in nature i.e. body is composed of three germinal layers, viz, ectoderm, mesoderm and endodermEXTERNAL FEATURES Their bodies are compressed dorsoventrally and shows bilateral symmetry. Body shape generally worm like but vary from moderately elongated flattened to long flat ribbons and leaf like. The flat worms are small to moderate in size varying from microscopic to as long as up to 10-15 m. Majority of animals are white or colourless, some derive colour from ingested food. Anterior end of body is differentiated into head. Ventral surface bearing mouth and genital pores. Presence of great variety of adhesive parts e.g. suckers. Body is covered by cuticle or by ciliated epidermis. Hard part consist of cuticle, spines, thorns or hooks etc.INTERNAL FEATURES Endo and Exo skeleton are completely absent, hence the body is generally soft. Acoelomate i.e. true coelom is absent. Body space between various organs is filled with MESENCHYME. Digestive system is poorly developed or absent. Respiratory and Circulatory systems are absent.

Excretory system consists of Protonephridia or flame cells. Nervous system is primitive. The main nervous system consists of a pair of cerebral ganglia or brain and 1-3 pairs of longitudinal nerve cords, connected to each other by transverse commissures.REPRODUCTION Platyhelmenthes are hermaphrodite i.e. male and female sex organs are present in same individual. In majority of forms eggs are devoid of Yolk but provided with special yolk cells. Cross fertilization as well as self fertilization is present. Life cycle may be simple or complicated involved one or more hosts.EXAMPLESPlanaria, Liver flukes, Schistosoma and Taenia Solium etc.

Phylum Aschelminthes (Nematoda/Round worm)MAIN CHARACTERS HABIT AND HABITAT Nematoda have a very wide distribution and they seem to have mastered almost every habitat. Free living nematodes are found in the sea, fresh water or in the soil in all kinds of environment. There are also many Parasitic nematodes found in all groups of Plants and animals. The Saprophagous species live in decomposing plant and animal bodies and in rotting fruits.NATUREThey have a bilaterally symmetrical, cylindrical body, glistening smooth surface. They are triploblastic.EXTERNAL FEATURES They show no trace of segmentation. Most of the free living nematodes are less then a millimeter length.

Some of the parasitic species attain a length of several meters e.g. Guinea worm (Dracunculus medinensis). They are usually long, round, tapered at both ends showing very little morphological diversity from species to species. The mouth of nematodes is modified for various modes of feeding such as cutting, tearing, piercing and sucking fluids from the host. Body is covered by cuticle, which moults only during the period of growth.INTERNAL FEATURES The organs are packed in parenchyma when young, but later on it disappears in adult. So that organs lie in a fluid filled cavity. This cavity is termed as PSEUDOCOEL and it has not peritoneum. Muscles are only longitudinal. Excretory system has no flame cells. Alimentary canal is straight with ectodermal fore and hind gut and an endodermal mid gut.REPRODUCTION Sexes are generally separate. Gonades are tubular and continues with their ducts. Female organs are usually paired and open by vulva. Male organs are single and open into a cloaca. The life cycle of Parasitic species involves one, two or more hostsEXAMPLESAscaris (Round worms), Hookworms and Thread worms etc

Phylum Annelida (Segmented worms)MAIN CHARACTERS NATUREAnnelida are triploblastic, symmetrical, coelomata and segmented metozoa.HABIT AND HABITATAnnelida are mostly aquatic, marine or fresh water, burrowing or living in

tubes, some free living forms.EXTERNAL FEATURES The most important feature of annelida is their metameric segmentation. (External segmentation) Segmentation is indicated externally by circular constrictions or grooves on the body wall. Outer covering of the body is cuticle secreted by the underlying epidermis. Appendages, when present are unjointed. Locomotory organs are segmentally arranged, paired setae or chaetae.INTERNAL FEATURES Body wall is contractile, consists of an outer epidermis, circular and longitudinal muscles. The gut, longitudinal blood vessels and the nerve cord extend throughout the body length, whereas other structures are repeated in each segment. Important character of annelida is the development of series of coelomic compartments in their body between the gut and the body wall. The Coelom is a cavity, which develop within the mesoderm and is lined by mesodermal cells. Segmented musculature plays an important part in locomotion of Annelids.SYSTEMS OF BODY Alimentary canal is tube like extending straight from mouth to anus. Respiration through general body surface, by gills in some forms. Blood vascular system is closed type. Blood is red due to haemoglobin. Excretory organs are Nephridia usually one pair in each segment. Nervous system consists of dorsal brain and longitudinal ventral nerve cord. Sexes may be united or separate. Development is direct when sexes are united and indirect when sexes are separate.EXAMPLESNereis, Earthworm and Leeches etc.CLASSIFICATION OF PHYLUM ANNELIDAPhylum Annelida is divided into four classes:1. Polychaeta2. Oligochaeta3. Hirudinea4. Archiannelida1.POLYCHAETALOCOMOTORY ORGANSThe Polychaetes possess paired parapodia functioning as locomotry appendages, are present only in the class Polychaeta.

PROSTOMIUMUsually there is a distinct head or Prostomium bearing sensory and feeding appendages.MODE OF LIFEThe Polychaetes may be carnivorous, scavengers, or filter feeders.REPRODUCTIONThe sexes are separate and fertilization of eggs takes place outside body. Their free swimming larva is called Trochophore.RESPIRATIONThe respiration takes place through the body surface in many but in some gills may be present as respiratory organs.EXAMPLESSome well-known examples of marine polychaetes are Nereis, Arenicola and Sabella. Nereis lives beneath stones and in crakes of rocks.2.CLASS OLIGOCHAETALOCOMOTORY ORGANSThe Oligochaetes possess fewer numbers of Setae as compared to the Polychaetes. The setae help the earth worms in crawling.SENSE ORGANSThere anterior end lacks eyes, or sensory appendages.CLITELLUMAt sexual maturity, all of the oligochaetes develop in several segment, glandular epithelium, called clitellum.MODE OF LIFE Oligochaetes live either in fresh water or on land. There is no free swimming larval stage in their development Majority of oligochaetes are scavengers, feeding on decomposing organic matter. Some fresh water species feed on algae. Burrowers like earth worm ingest a large quantity of soil, digest the organic matter and the living fauna.RESPIRATIONRespiration takes place through their general body surface. Some aquatic species possess anal gills.ECONOMIC IMPORTANCEEarthworms increase the fertility of soil by physically over turning it. They ingest the soil, break it down and deposit it in the form of casts. The over turned soil is relatively in proportions of total nitrogen, organic carbon, calcium, magnesium and phosphorus.3.CLASS HIRUDINEABODY SEGMENTSUnlike polychaetes and oligochaetes, the number of body segment in leeches is fixed at 34.SUCKERSThe anterior and posterior body segments are fused to form suckers.LOCOMOTIONLeeches either swim or crawl.

RESPIRATIONRespiration generally takes place through the body surface. Leaf like gills may be present.PARASITIC NATUREMost leeches feed by sucking blood of aquatic invertebrates and vertebrates.4.ARCHIANNELIDA It is a small group of marine worms. They are not segmented externally and don’t have bristles. They live in the sea and show annelid characteristics to a minor extent. Their development is also characterized by Trochophore Larva.EXAMPLESNerillaDinophilus

Phylum Arthropoda (Jointed Appendages Animals)MAIN CHARACTERS Arthropoda is the largest Phylum of the animal kingdom including 10, 00000 species of different types of animals. The word Arthropods is derived from Greek Arthos – Jointed and Podos – Foot.HABIT AND HABITATArthropodes have undergone an adaptive radiation for aerial, aquatic, terrestrial and parasitic environment. They are widely distributed in each and every place of the world.NATUREArthropoda are “bilaterally symmetrical,” metamerically segmented metazoa.EXTERNAL FEATURES Their body is covered by an exo-skeleton of “chitin” and protein. They possess paired jointed appendages.

Their metamers are not alike but are specialized and their number is generally fixed. The head is well developed.INTERNAL FEATURES Musculature is not continues but comprises separates striped muscles. The coelomic space in Arthropods is occupied by the blood vascular system and is thus called “Haemocoel.” Digestive tract is complete; mouth and anus lie at the opposite end of the body. Circulatory system is open with dorsal heart and arteries but without capillaries. Respiration through general body surface, by gills in aquatic forms, trachea or book lungs in terrestrial forms. Excretion by “Malpighian tubules” or Coelomoducts. Sexes are generally separate and sexual dimorphism is often exhibited by several forms. Fertilization is internal. Development is usually indirect through the larval stage. Nervous system of arthropods is quite similar to that of annelids and consists of dorsal anterior brain and a double ventral nerve cord.CLASSIFICATION OF ARTHROPODAPhylum Arthropoda is divided into following five classes:1. CLASS MEROSTOMATA Almost all members of the class Merostomata are extinct. The only living merostomes, the king Crabs have survived. The animals are horse-shoe shaped. The long spike like tail that extends, posteriorly is used in locomotion. It is called “Telson.” They feed on mollusks, worms and other invertebrates that they find on the ocean floor. King Crabs a hors-shoe crabs have a tough “Carapace” jointed to a smaller abdomen. E.g:Limulus Polyphemus (King Crab).2. CLASS ARACHNIDA This class includes spiders, scorpions, mites, ticks and many other terrestrial arthropods. The Arachnid body consists of a cephalothorax and abdomen. Cephalothorax is comprised of fused head and thorax. Arachnids have six pairs of jointed appendages. Most Archnids are carnivorous and prey upon insects and other small arthropods. Respiration in archnids takes place either by trachea or book lungs or by both.

They are mainly terrestrial arthropods. They have no antenna. Cephalothorax is non-segmented.E.g: Scorpions, Ticks & Mites, Spiders3. CLASS CRUSTACEA They live both in marine and fresh waters. A few are terrestrial. Crustaceans are unique among arthropods in possessing two pairs of antenna. They always have one pair of mandibles and two pairs of maxillae around the mouth. Mandibles are usually adapted for biting and chewing. Maxillae are used for holding the food. Their body is divided into three distinct parts, i.e. the head, thorax and abdomen. Respiration usually takes place through gills associated with appendages. The sexes are usually separate and the reproduction is sexual. The thoracic and abdominal appendages may be variously modified for walking, swimming, feeding, respiration or as accessory reproductive structures.E.g: Sacculina (Parasitic Crustacean), Astacus (Cray-fish), Prawns, Shrimps, Lobsters and Crabs etc.4. CLASS MYRIAPODA All the animals are terrestrial. Their body is divided into a head and an elongated trunk with many segments. Each segment bears one or two pairs of legs. They are carnivorous /herbivorous. Eyes may present or absent.E.g: Millipedes and Centipedes etc.5. CLASS INSECTA (HEXAPODA) Insecta is the largest class of the animal kingdom.HABIT AND HABITAT In their adaptive radiation, approximately a 8,50,000 species of insecta have occupied all types of terrestrial habitat. Some live in fresh water, however one small group is marine.NATURE AND ADAPTATIONS The great success of insects can be attributed partly to the development of flight in them. Flight has provided them the great capacity of dispersal, access to food sources, and favourable habitat and escape from enemies. Corresponding to their number of species, there exists a huge variation in their structural and biological adaptations.

EXTERNAL FEATURES All insects have their body divided into three well-defined regions i.e. the head, thorax and abdomen. There is always a pair of antenna on the head. The thorax always consists of three segments:(a) Prothorax(b) Mesothorax(c) Metathorax Each thoracic segment bears a pair of legs. Head consists of six fused segments and a pair of compound eyes and mouth parts. Abdomen comprises 7-11 segments and devoid of appendages.MOUTH PARTSThe feeding appendages consists of three pairs:(a) Mandibles(b) First Pair of Maxilla(c) Second Pair of Maxilla The second pair of maxillae have fused together to form the “LABIUM,” or lower lip The upper lip is formed by the projections head and is called the “LABRUM.’Types:- The mouth appendages have been greatly modified to form five basic types of pattern:(i) Biting(ii) Chewing(iii) Piercing(iv) Sucking(v) Siphoning or SpongingINTERNAL FEATURES Heart is elongated, tubular and divided into chambers situated in the abdomen. Excretion takes place through “Malpighian tubules.” Liver is absent but salivary glands are usually present. Respiration is by “TRACHEA”. External gills may be present as accessory respiratory organs in some aquatic insects.REPRODUCTIONReproduction is sexual in most insects. However it takes place parthenogenetically i.e. eggs developing without being fertilized by sperms in a number of insects e.g: Aphids and Termites etc.METAMORPHOSIS The development of insects after hatching from egg into adult stage involves considerable growth and in some cases drastic morphological changes. The entire post-hatching development is termed as “Metamorphosis.”(A) INCOMPLETE METAMORPHOSIS

In some insects the immature form that hatch from the egg are essentially similar in shape to their adults, but are smaller in size, lack wings and reproductive organs They attain adult characters after some growth period. This type of metamorphosis is called “Incomplete Metamorphosis.” Three stages are Egg → Nymph → Adult.For example Cockroach, Grasshopper, Bugs etc.(B) COMPLETE METAMORPHOSIS In this type the animal shows following stages during its complete development: Egg → Larva → Pupa → Adult.For example Mosquito, Butter fly, House fly etc.ECONOMIC IMPORTANCE OF INSECTSInsects are of very great importance to man.BENEFICIAL INSECTS1. Apis, the honey bees produce honey and also give wax.2. Insects bring about the cross-pollination.3. Bombyx and Eupterote are silk-moths and produce silk.4. The larvae of Lucilla and Pharmia are used in wound healing of bones.5. Some insects feed upon and destroy harmful insects.6. Some insects are ScavengersHARMFUL INSECTS1. Many types of mosquitoes, flies, fleas, lice and bugs transmit diseases to man and animals.2. Human food is spoiled by cockroaches, ants and flies.3. Tinea and Teniola are cloth-moths and destroy cloths.4. Tenebrio is mealworm. They eat meal, flour and grains.5. Lepisma destroy the books.6. Termites destroy books and wood.7. Many insects injurious to crops e.g. Tree hoppers, Leaf hoppers, Aphids, White flies and bugs.

Phylum EchinodermataGENERAL CHARACTERS HABIT AND HABITATThe Echinodermates are exclusively marine including the largest invertebrate “Giant Squids.”EXTERNAL FEATURES

Symmetry usually radial, nearly always pentamerous. Body shape is rounded to cylindrical or star like. Surface of the body is rough. Body wall consists of an outer epidermis, a middle dermis and inner lining of peritoneum.INTERNAL FEATURES Endoskeleton consists of closely fitted plates forming shell usually called “THECA,” may be composed of separate small “OSSICLES.” Coelom is spacious, lined by peritoneum and occupied mainly by digestive and reproductive systems. Presence of “Water Vascular System” is most characteristic feature. Alimentary tract is usually coiled. Circulatory or Haemal or blood lacunar system is typically present. Excretory system is wanting. Nervous system is primitive, consists of ganglionated nerve cord. Sense organs are poorly developed. Sexes are usually separate. Reproduction is usually sexual, fertilization is external.WATER CANAL SYSTEMWater canal system is unique in possessing an internal closed system of canals containing a watery fluid.REGENERATIONRegeneration of lost part is commonIMPORTANCE OF WATER CANAL SYSTEMThese canals are provided with tubular protrusions called “Tube Feet,” which serve a number of functions like locomotion, anchoring to hard surfaces, grabbing the prey, diverting food particles towards mouth and in some cases also respiration. The watery fluid is drawn from the surrounding water through a perforated disc called the “Madreporite.”EXAMPLEStar Fish, Brittle stars, Sea urchins, Sea-cucumbers, Sea-Dollar, Sea-lilies and Feather stars.LARVABipinnaria larva

Phylum HemichordataGENERAL CHARACTERS It is a small group of animals, which include about 90 species. They are soft-bodied animals, which usually live in shallow “U” shaped burrows in the sandy or muddy sea bottom.EXTERNAL FEATURES They are cylindrical or vase shaped animals, bilaterally symmetrical and lack any segmentation. They may be solitary or colonial and usually range between a few millimeter and 250 cm in length. Sexes are separate in hemichordates.INTERNAL FEATURES Circulatory system is open and coelom is divided into three chambers. A dorsal and a ventral nerve cord are present.LARVATornaria larvaEXAMPLEBalanoglossus, Acron worm etc.

Phylum ChordataGENERAL CHARACTERS The chordate animals at some time in their life history exhibit the following diagnostic characters:1. NOTOCHORD It is an elastic, solid, skeletal rod lying below the nerve cord and above the alimentary canal. It serves as a primitive internal skeleton and acts as a rigid axis. It may persist throughout life or it may be replaced partially or completely by a backbone or vertebral column.

2. DORSAL HOLLOW NERVOUS SYSTEM There is a dorsal, hollow, fluid filled nerve cord. It is formed by enfolding of a mid-dorsal strip of ectoderm and it generally sinks below the surface. It lies above the notochord and outside the coelom. It persists throughout life in most chordates, but in a few it degenerates before maturity.3. GILL CLEFTS These are paired openings leading from the Pharynx to the exterior. Such gill clefts appear during the development of every chordate, but in many aquatic forms they are lined with vascular lemallae, which forms gills for respiration. In terrestrial chordates, which never breath by gills, gill clefts are present during early development but later on, they disappear.4. PHA-RYNGEAL POUCHES All the chordates have paired pharyngeal pouches at some stage of their life cycle. These extend from laterally from the anterior part of the digestive tract towards the body wall.OTHER FEATURES Chordates are triploblastic. They are bilaterally symmetrical. True coelom is found. They are found in almost all the habitats of the World.CLASSIFICATION OF PHYLUM CHORDATAThe Phylum Chordata is divided into two groups which are:1. Acraniata (Protochordata)2. Craniata (Vertebrata)1. GROUP ACRANIATA (PROTOCHORDATA) They are first or simple Chordates. Brain box (Cranium) is absent and hence brain is not prominent. Notochord does not transform into vertebral column.This group is further divided into two sub-phyla, which are as follows:a) Sub-Phylum Urochordata (Notochord in tail)b) Sub-Phylum Cephalochordata (Notochord head to tail)A) SUB-PHYLUM UROCHORDATA (NOTOCHORD IN TAIL) They are also known as “Tunicates” because their body is enclosed in a sac called “Tunic.” All members are marine and sessile. Body possesses two openings, an incurrent or buccal siphon and an excurrent or Atrial siphon, through these openings exchange of gases and food or waste material take place. As a result of “Retrogressive metamorphosis” the larva loses its tail and most of chordate characters and converts into an adult.

E.g: Ascidia, Herdmania etc.B) SUB-PHYLUM CEPHALOCHORDATA (NOTOCHORD FROM HEAD TO TAIL) This is a small group of marine animals, body with pointed ends. Usually live buried in sand, in shallow water with anterior end protruded out. They show all typical chordate characters (hollow dorsal nerve chord, pharyngeal gill slits and notochord). Only two genera are present around the world.E.g: Branchiostoma (Amphioxus) etc2. GROUP CRANIATA (VERTEBRATA) In these chordates brain is protected inside a skeletal brain box called “CRANIUM.” Also known as “Vertebrates” because notochord is replaced by a vertebral column. This group is sub-divided into two sub-phyla, which are as follows:a) Sub-Phylum Agnatha (Mouth without Jaws)b) Sub-Phylum Gnathostomata (Mouth with Jaws)A) SUB-PHYLUM AGNATHA (MOUTH WITHOUT JAWS) This is a small group of marine vertebrates also known as “Cyclostomes.” Superficially they resemble the fish but lack the jaw so they are often known as “Jawless Fishes.” They have rounded suctorial mouth with many rings of teeth. Paired fins and scales on body. Usually parasitic in nature.E.g: Hag Fish, Lamprey etc.B) SUB-PHYLUM GNATHOSTOMATA (MOUTH WITH JAWS) It is a large group of vertebrates with both upper and lower jaw. Teeth may be present or absent.Gnathostomata are divided into two super classes, which are as follows:i) Pisces (Fishes)ii) TetrapodaI) SUPER CLASS PISCES (FISHES) This is the largest group of chordates, which includes half of the chordate (25,000 species). Study of fishes is called “Ichthyology.” Body is streamlined with paired fins and covered over by dermal scales.Super class Pisces is divided into two classes, which are:i-a) Chondrichthyes (Cartilage Fishes)i-b) Osteiochthyes (Bony Fishes)I-A) CLASS CHONDRICHTHYES (CARTILAGE FISHES) Alternate name is “Class Elasmobranchi.” Usually includes marine fishes with endoskeleton of cartilage (soft bone). Skin contains sharp tiny enamel coated denticles called “Placoid Scales,” which form exoskeleton.

Mouth is ventral in position and tail fin is “Heterocercal.” Five exposed gill slits, which are not covered over by a gill cover. Common examples are Skates, Sharks, Rays and Scoliodon (Dog Fish)- a small Shark etc.I-B) CLASS OSTEIOCHTHYES (BONY FISHES) Alternate name is “Teleostom,” actually the largest class of chordates. Includes marine and fresh water fishes. Mouth is present at anterior tip. Endoskeleton in these fishes is made up of hard bone while exoskeleton is made up of thin bony plates, which are known as “Cycloid” or “Ctenoid scales.” Gills are covered over on each side by a gill cover called “Operculum.” An air bladder is present which acts as a hydrostatic organ. Tail fin is usually “Homocercal or Diphycercal.” Common e.g are Eel, Sea-Horse, Flying Fish, Globe Fish etcLUNG FISHES Zoogeographically important fishes, belonging to group “Dipnoi, included in Class Osteiochthyes. Only three living genera. They respire by gills and by lungs during drought period (Lungs-Modified air bladder). Limited distribution in South America, Africa and Australia.E.g: Protopterus (African Lung Fish)II) SUPER CLASS TETRAPODAIt includes following classes:a) Class Amphibiab) Class Reptiliac) Class Avesd) Class MammaliaA) CLASS AMPHIBIA This class includes the animals that came out of the water and established a successful life on land. They took advantages of the improved possibilities by remaining close to water, by keeping a soft and moist skin, by developing lungs and by evolving a bony skeleton with a strong vertebral column and four legs. They cope with seasonal changes by burrowing during extreme cold and save water by sealing themselves in a mucous envelop on dry land. The bony endoskeleton is the main body support. The notochord is absorbed during development Breathing is mostly by means of skin and also lung, and also by lining of buccal cavity. In larva the breathing is mostly by means of external or internal gills.

The circulatory system shows a three chambered heart, with two atria and one ventricle. The amphibians are “Cold Blooded” (Poikilothermic) that is having internal temperature that very with the environment. Eggs and sperms are laid in water and fertilization is external.E.g: Frog and Toads, Salamanders, Newts, Mud puppies etc.B) CLASS REPTILIAGENERAL CHARCTERSThe earliest reptiles evolved from the amphibians.HABIT AND HABITATReptiles are generally well adapted to life on land, in semi-dry, completely dry and even desert habitat.NATURE All reptiles lay their eggs on land. They are cold-blooded animals and are less active during low temperature.STRUCTURAL FEATURES They possess dry skin covered with epidermal scales. In some lizards and crocodiles, small bony plates develop below the epidermal scales. The skeleton is built on the same plane as that of amphibians, but is much stronger to support their body weight. Respiration takes place exclusively through lungs. Heart is three chambered, two auricles and one incompletely divided ventricle. (In Crocodiles, the ventricle is completely divided into two chambers.) The excretion takes place through kidneys. The reptiles secrete much of their waste products in form of non-toxic “Uric-Acid.”REPRODUCTION In most reptiles fertilization is internal. Eggs are provided with a shell and are laid on land. The early development of embryo takes place on the large quantities of yolk and albumin present in the egg. Due to the presence of a protective membrane called “AMNION” in the egg, reptiles are included in the “Amniota Group” of Vertebrates.EXAMPLEAlligators, Crocodile, Snake, Turtle and Gecko etc.C) CLASS AVES (BIRDS)EVOLUTION Aves have evolved from reptiles. As they acquired the capability of true flight they were able to exploit the aerial environment and became the largest class of terrestrial vertebrates.CHARACTERS OF CLASS AVESHABIT AND HABITAT

The birds live from pole to pole in all type of ecological zones. They all breed on land.FLIGHT AND ADAPTATION Feathers differentiate birds from all other vertebrates. Feathers originated as extraordinary development of Reptilian scales. Instead of growing all over the body and spreading evenly, the feathers grow in definite tracts. The feathers play an important role in the thermoregulation of birds. They trap air, which is a bad conductor of heat and so prevent loss of body heat. To fly efficiently the birds have reduced their body weight in a variety of ways. Many bones become hollow, thin and light. Synsacrum and pygostyle are formed by the fusion of vertebrae and give strength to skeleton. Birds possess strong muscles to control the use of wing in flight.ADAPTATION FOR COMMUNICATION They possess large eyes with well-developed sight. The birds communicate with members of their species with sound signals for which the sense of hearing is well developed.STRUCTURAL FEATURES The great mobility of neck is helpful in feeding, nest building, preening and defence. There are developed a number of types of bills according to their feeding habits. The digestive system of birds is compact and can accommodate large quantity of food. The food is stored for a short period in the crop. “Gizzard” possess thick muscular wall with horny lining, small stones swallowed by birds are passed on the gizzard for grinding the food. The “Syrinx” or sound-producing organ is found in no other vertebrate except the birds. It is located at the junction between the trachea and the paired bronchi. The lungs of birds are small, solid, spongy and slightly distensible. They are in contact with a number of air sacs.MIGRATION IN BIRDSA large number of species of birds exhibit a deep-rooted phenomenon of migration, during which they travel long distances from their summer breeding homes towards areas of warm climate.SUB-CLASSES OF AVESThere are two main sub-classes of aves, which are:i) Sub-Class Ratitae (Flightless Birds)ii) Sub-Class Carinatae (Free-Flying Birds)I) SUB CLASS RATITAE (FLIGHTLESS BIRDS)

This sub-class includes modern big sized flight less birds. They comparatively have heavy weight and their wings are either vestigial or rudimentary. They have a flat sternum without keel. Their flight muscles are poorly developed. The distribution of these birds is restricted to few areas of the World.E.g: Ostrich, Rhea, Emu, Cassowary, Kiwi and Penguin.II) SUB-CLASS CARINATAE (FREE FLYING BIRDS) In this sub-class modern flying birds are included. They are usually small, light weight birds with highly developed wings and feathers with interlocking system. They possess sternum with a crest like keel to accommodate the hightly developed pectoral flight muscles. The flying birds are distributed all around the World.E.g: Sparrow, Pigeons, Myna, Bulbul, Hoopoes, Crow, Doves, Parrots, Fowls, Cuckoo and Ducks etc.D) CLASS MAMMALIAGENERAL CHARACTERSEarly mammals are originated from reptiles. The distinctive characteristic of mammals are at the highest grade of development in animal kingdom.HABIT AND HABITATMostly terrestrial, a few aquatic.NATURE They are warm-blooded animals. They can maintain a fairly high body temperature and so can successfully survive in colder areas of the world.TEMPERATURE REGULATION Heat is generated by high metabolic rate of their body and is lost by increasing blood circulation in the skin and evaporation of sweat. The mammalian body temperature is maintained at 35˚C-40˚C.APPARENT FEATURE All mammals possess hair on skin. Sweat glands and sebaccous glands are present on skin. Mammary glands secrete milk in females. External ears (Pinna) are present. Teeth are heterodont i.e. not uniform. The different types of teeth are: Incisors, Canine, Premolars, Molars.SKELETAL SYSTEM Skull with two occipital condyles is present. Lower jaw is composed of single bone on each side. Vertebrae are “Gastrocentrous,” composed of three pieces i.e. the centrum and two epiphyses. Digits of fore and hind limbs are usually five.

Cervical (Neck) vertebrae are seven.INTERNAL FEATURES A thick muscular septum “Diaphram” is present between abdomen and thoracic cavity. Heart is four-chambered. R.B.Cs are non-nucleated. Brain with four optic lobes. Kidney is metanephrous. The stomach is simple sac but rarely complicated.REPRODUCTION Mammals give birth to young ones (Viviparous), which are nourished by parents. Except Prototherians that lay eggs. Fertilization is internal. Development of eggs occurs in the uterus of female, where the developing embryo develops relationship with mother (Placenta). After the birth of the child, the mother nourished her young ones.CLASSIFICATION OF CLASS MAMMALIAMammals are divided into three sub-class:1. SUB-CLASS PROTOTHERIAIncludes the egg laying mammals. For example Duck billed, Echidna (Spiny anteater).2. SUB-CLASS METATHERIAIncludes the pouched mammals, also known as “Marsupial mammals.” For example Kangaroo, Koala Bear and Opossums etc.3. SUB-CLASS EUTHERIAIncludes the placental mammals. For example Monkey, Cow, Elephant, Cat, Dog, Bat, Whale and Human being etc.

Summary of Kingdom Anamalia

1) PHYLUM PORIFERA Porous body CaCO3 Silica Skeleton Asymmetrical Amphiblastula larva Diffuse cellular organization Spongocoel body cavity(2) PHYLUM CNIDARIA Radially symmetrical Body cavity “Coelentron” Pnedoblast – Defensive cells Diploblast (Ecto + Endoderm) Middle non-cellular layer “Mesoglea” Larva – Planula Larva Morphologicallya- Medusa = Umbrella likeb- Polyp = Rod shaped(3) PHYLUM PLATYHELMINTHES Flatworms Totally Parasite Flat or Ribbon shaped Excretory organs – Proto nephridia (Flame cells) Aeoelomate (Absence of body cavity) It is the first phylum containing triplo blastic animals Usually Hermaphrodites Planaria is the only free living member High fertility rate Bilaterally Symmetrical(4) PHYLUM ASCHELMINTHES (NEMATODA – ROUND WORMS) Totally parasitic including 50 human parasite Bilaterally symmetrical with cylindrical body Two openings (Mouth & Anus) Psudocoelomates Common diseases – Ascariasis, filiariasis (elephantiasis), hook worm infection.(5) PHYLUM ANNELIDA (SEGMENTED WORMS) Metamers (External segmentation) Septae (Internal segmentation) Setae (Locomotary organs) or cheata Digestive, excretory, nervous, reproductive system well developed. Respiration through diffusion

Blood is red with a closed type of circulatory system (with many pulsatile hearts)CLASS POLYCHEATA Setae with Parapodia Separate sexes Sabella (Peacock worm), Nereis (Clam worm)CLASS OLIGOCHEATA Setae without Parapodia Pheretima (Earth worm)CLASS HIRUNDINIA (LEACHES) Free living, Ecto or Endo parasite Contains a Enzyme hirudin which prevents blood clotting(6) PHYLUM MOLLUSCA (SOFT BODIED ANIMAL) Second largest phylum Largest invertebrate – Gram squlds External hard covering calcium carbonate shell A grinding structure radula is present in the buccal cavity Thin membraneous covering of the body – mantle Respiration through gills Locomotary organ a mascular foot Larva – Trocophore larvaCLASS GASTROPODA A phenomenon torsion is present in which the animal body rotates at the angle of 180˚Example: PilaCLASS BIVALVIA Second largest class of mollusca Shell consist of two parts and attached with eachother by hinge joint Common examples: Unio, mytilus and pearl oystersCLASS CEPHALOPODA All members are marine Locomotary organ foot transformed into suckers which bears tentacles and arms Example: Sepia (cuttle fish), loligo (squids), octopus (devil fish) Shell is absent in octopus(7) PHYLUM ARTHROPODA ( JOINTED LEGS) Largest phylum One million species Metamerically segmented animals Blood filled cavity hoemocoel is present Blood without haemoglobin (white)

Respiration: Gills, Trachea or Book lungs Excretory organs malphigian tubules Nervous system well developed Compound erges with sharp vision Metamorphosis = developmental changes which transforms a larva into its developed adult form Incomplete metamorphosis = egg → nymph → adult e.g. cockroach Complete metamorphosis = ® egg ® larva ® pupa ® adult e.g. Butterfly, common, housefly and mosquito Moulting (ecdysis) Changing over of old exoskeleton and formation of a new one Apiculture => Farming of honey bees Sericulture => Farming of silk wormsCLASS MEROSTOMATA Limulus (king crab)CLASS ARCHINIDA (SPIDER LIKE) Group of Spiders & Scorpions Respiration through book lungs Four pair of walking legsCLASS CRUSTACEA Class of prawns, shrimps, lobsters, crabs Two pairs of antenae, one pair of mandible and two pair of maxilla Exoskeleton a large plate of carapase Sacculina is the only parasitic memberCLASS MYRIAPODA Class of millipedes and centipedes Body is divided into similar multiple segmentsCLASS INSECTA OR HEXAPODA Largest class (eight lakhs & 50,000 members) Study of insects is called entomology Three pairs of walking legs Pterygota (insects with wings) Apterygota (insects without wings) Social insects: Ants, termites, honey bees(8) PHYLUM ECHINODERMATA (ANIMAL WITH SPINY SKIN) Marine animals Radially symmetrical Pentamerous body Water vascular system is present Locomotary organs are tube feets = External openings of the water vascular system

Exoskeleton is made up of calcarious plates in the form of spines Power of regemeration is very great Phylum echinodermata, hemichordata & chordate posses common ancestor Bipinnaria larva is present Common e.g. Sea Star (Star fish, Brittle star, Sea dollar, Sea urchins, Sea cucumbers.(9) PHYLUM HEMICHORDATA (ANIMAL WITH HALF NOTOCHORD) Notochord in future = Vertebral column + Skull Dorsal nerve cord = Brain and Spinal cord Pharengeal gill slits <–>Aquatic animals = gills -> Terrestrial = Internal neck structures Only 90 species are present Larva is tornaria larva Open circulatory system(10) PHYLUM CHORDATAGROUP ACRANIATABrain without any covering or skullSUB-PHYLUM UROCHORDATA Also known as tunicates Body is enclosed in a sac tunic Only embryonical stages show chordate charactersSUB-PHYLUM CEPHALO CHORDATAEmbryonic as well as adult both forms show typical chordate charactersGROUP CRANIATA OR VERTEBRATABrain and spinal cord is enclosed in a hard covering skull & vertebral column respectivelySUB-PHYLUM AGNATHA (ANIMALS WITHOUT JAWS) Also known as cyclostomes or jawless fishes Totally parasitic Teeth are present in the form of rings Common e.g. Hag fishes, lampreySUB–PHYLUM GNATHOSTOMATA (ANIMAL WITH JAWS) Teeth may be present or absent Amphibians and bird lack teeth Fishes, reptiles, mammals do have teeth1. SUPER – CLASS PICSES (FISHES)Study of fish is known as echthylogySUB – CLASS CHONDRICHTHYES (CARTILAGENOUS FISHES) Endo skeleton is cartilaginous (soft boned) Exoskeleton – Placoid scales Fins are heterocircle (different size and shaped)

Gills without any covering Common example (Sharks, Squids, torpedo, electric ray) Scolidoen (dog fish) – Small SharkSUB – CLASS OSTEOCHYTHES (BONY FISHES) Exoskeleton cycloid or ctenoid scales Operculum is present (covering of gills) Fins are homocircle (Same size and shape) Lung fishes are included in order dipnoi.2. SUPER CLASS TETRAPODA1. CLASS AMPHIBIA Exoskeleton is absent Respiration by lungs, gills or skin Fertilization is external Cold blooded Having the characteristics of hibernation & aestivation Common e.g. Toads, frogs, salamanders etc.2. CLASS REPTILIA Included in group amniota due to the presence of amnion in eggs Fertilization is internal Exoskeleton is made up of thick horny scales Important members are snakes, turtles, lizards, crocodiles and alligators Venom → Snake poison Fangs → sharped and curved teeth of snake3. CLASS AVES (BIRDS) Study of birds is called ornithology They posses hollow bones (Pneumatic bones) Sound producing organ “Syrinx” is present instead of larynx. Teeth totally absent.SUB CLASS RETITA (FLIGHT LESS BIRDS)E.g. Penguin, Kiwi, Ostrich.Ostrich → Largest Bird.SUB CLASS CARNIATAE (FLYING BIRDS) Wings with interlocking system. Common e.g. Peacock, Seagulls, Kites, Falcon etc. Archeopetryx → Intermediate specie between reptiles and birds.4. CLASS MAMMALIA Presence of mammary glands and hairs. A muscular organ diaphragm, which separates thoracic cavity from abdominal cavity. Teeth are present with different size and shape (heterodont).

a- Incissors → for biting and cutting purposeb- Canives → Tearing purposec- Pre-Molars -> For grinding and holding purposed- Molars -> For grinding and holding purposeSUB CLASS PROTOTHERA (EGG LAYING MAMMALS) Also called monotremous. Two genera with 3 species Oviparous. Common urogenital opening Cloaca is present. External ear is absent. It is a connecting link between reptiles and true mammals. e.g. spiny anteater, duck billed platypus.SUB CLASS METATHERIA (POUCHED MAMMALS) Marsupials Give birth to live young ones. Special pouch like bag is present in the ventral side of female. This pouch is known as marsupial. Common e.g. Kangaroo, Kuala bear, Opossums.SUB CLASS EUTHERIA (PLACENTAL ANIMALS) 95% of mammals are included in this group. Viviparous. Placenta → connecting link between mother and fetus. Common e.g. Camel, donkey, elephant, bat, whale, dolphin. Markhor is the national animal of Pakistan also known as Wild goat.

Bio-EnergeticsDEFINITION The capturing and conversion of energy from one form to another in the living system and its utilization in metabolic activities is called Bioenergetics.

Bio-energetics is the quantitative study of energy relationships and conversion into biological system. Biological energy transformation always obey the laws of thernodynamic.ROLE OF ATP AS ENERGY CURRENCYATP is adenosine triphosphate. Adenosine is made of adenosine and ribose sugar. Among the three phosphate groups two are energy rich PO4 bonds. So ATP is a high energy compound it gives its PO4 groups easily. When 1 ATP is converted into ADP, 7.3 K cal/mole or 31.81 KJ/mole energy is released. ATP -> ADP + Pi + EnergyLiving organisms use organic food for generation of energy. These food usually contain carbohydrates which degrade to produce CO2, H2O and energy. Which is usually in the form of ATPs. ATP plays role in several endergonic and exergonic reactions.ENDERGONIC REACTIONSThose chemical reactions which accompanied by the absorption of the energy are known as endergonic reactions. The products have a higher free energy than reactants. Examples of endergonic reaction in human are1. Synthesis of proteins2. Synthesis of lipids3. Synthesis of cholestrol4. Synthesis of glycogenEXERGONIC REACTIONSThose reactions which complete along with the liberation of free energy are known as Exergonic reaction. The products have a lower free energy than the reactants.EXAMPLEAn aerobic glycolysis, Kreb’s cycle, oxidative phosphoylation.PIGMENTSSubstances in plants that absorb the visible light are called Pigments. Different pigments absorb light of different wavelength. They are involved in the conversion of light energy to chemical energy. Important plant pigments are chlorophyls, carotenoids, phycobilin, xanthophylls, phaelophytin.PHOTOSYSTEMEach photosystem is a highly organized unit consisting of chlorophyll accessory pigment molecules and electron carrier molecules present on the thylakoids of chloroplast. Each thylakoid contains many units of two photosystems the photosystem I and photosystem II. So chloroplast contains thousands of photosystem.The photosystem consists of chlorophyll “a” and “b” and carotenoids. Chlorophyll having empirical formula of C55H72O5N4Mg is almost identical to “Chlorophyll b” of empirical formula C55H70O6N4Mg. But the slight structural difference between them is enough to give 2 pigments slightly different absorption spectra and hence different colours “Chlorophyll a” is blue green while “b” is yellow green.

Hundreds of chlorophyll a, chlorophyll b and carotenoids cluster together in a photosystem. But only a single molecule of chlorophyll a acts like a reaction centre the rest of others absorbs a photon, the energy is transmitted from pigment, molecules to pigment molecules until it reaches a particular chlorophyll a located in the region of reaction centre, where it gives electrons to primary electron acceptorFIGURE 11.3 PAGE 260Hundreds of carotenoids are admixed with 2 types of chlorophyll molecules in photosystem, giving yellow and orange shades. Carotenoids can absorb wavelength of light that chlorophyll cannot transfer to chlorophyll a. Some times excess energy can damage chlorophyll a, so carotenoids accept energy from them, thus providing a function known as Photoreceptor.ROLE OF LIGHTLight has a dual nature, can behave like a wave or like a particle. It is composed of packets of energy called photons (hu). Light energy captured in the light harvesting complexes is efficiently and rapidly transferred to the chlorophyll molecules present in the photosynthetic reaction centre. When a photon of light hits these chlorophyll a molecules. The energy of these photons is absorbed and results in the elevation of an e- from the ground state to an excited state, level depends upon the energy and incident photon.A photon of red light has enough energy to raise an electron to excited state I and this energy is sufficient to carryout all the chemical reactions of photosynthesis.The energy transferred by blue light raise the electron to excited state –2. However the energy transmitted by red or blue photons to photosynthetic electron transport chain is exactly the same. This is because that extra energy is lost (from absorption of blue photon) by radiationless de-excitation.The excitation energy can be used in1. Photochemistry (i.e. it enter the photosynthetic electron transport chain)2. Lost as heat.3. Give fluorescence etc.PHOTOSYNTHESISPhotosynthesis is an anabolic process in which chloroplast of the plants take up CO2 and H2O and using light energy to synthesize carbohydrates. In photosynthesis, the light energy is converted to chemical energy. It is an oxidation reduction process in which water is oxidized and CO2 is reduced6CO2 + 12H2O -> C6H12O6 + 6H2O + 6O2 ↑In simple6CO2 + 6H2O -> C6H12O6 + 6O2 ↑This process divides into1. Light reaction2. Dark reaction1. LIGHT REACTIONIn the light dependent reactions, light energy is absorbed by chlorophyll and

other photosynthetic pigment molecules. It is then converted into chemical energy. Due to this energy conversion, NADPH+ and ATP are produced.Components of light reaction1. Light capturing chlorophyll molecules.2. Membrane bound protein complexes3. Mobile electron carriersCHLOROPHYLL MOLECULES AND PHOTOSYSTEMEach photosystem consists of a light gathering “antenna complex” and a “reaction centre”. The antenna complex has many molecules of chlorophyll a, chlorophyll b and carotenoids most of them channeling the energy to reaction centre. Reaction centre of photosystem I and II has one or two “chlorophyll a” molecules, primary electron acceptor, associated electron carriers of electron transport system and certain specific proteins known as chlorophyll-bound proteins which differs them from other “chlorophyll a” molecules of the same system. The “chlorophyll a” molecules at the reaction centre of photosystem I (PSI) has a maximum absorbance at 700 nm, while those of PS II absorb at 680 nm. Therefore these reaction centre are called P700 and P680 where P simply stands for pigment.COMPLEXESThere are 4 major groups of complexes.1. PS I2. PS II3. Cytochrome b/f complex4. ATPase complexThe PS I and ATPase or ATP synthase complex are present on non-appressed region of thylakoid. While PS II and light harvesting complexes (LHC II) are present on appressed side. The cyt b/f complex is randomly distributed throughout the mambrane.MOBILE ELECTRON CARRIERSTransport the excited electrons between the complexes. These are plastoquinone (PQ) plastocyanin (PC), ferredoxin (FD)ELECTRON TRANSPORTThis process occurs in several steps.(1) EXCITATION OF PS IIWhen chlorophyll a of reaction centre of PS II is striked by a photon, the energy of photon absorbs in it. This results in the elevation of an electron from the ground state to an excited state. The excited electrons produced within P680 is rapidly transferred to the primary electrons acceptors phaelophytin. So 2 electrons which are transformed has to be replaced which is done by water.(2) PHOTOLYSIS OF WATERIn the presence of light a water splitting enzyme complex extracts 4 electrons from two water molecules. Removal of electrons splits the water into two hydrogen ions 2H+ and oxygen atoms. The extracted electrons from water are supplied to PS II (P680) while the oxygen atom immediately combines with

another oxygen atom to form O2. Which is released during photosynthesis. The hydrogen ions or proton (H+) are stored in thylakoid space. The overall reaction will be2H2O -> 4 H+ + 4e- + O2(3) FLOW OF ELECTRONS FROM PS II TO PS IPhotoexcited electrons accepted by phaelophytin from PS II are transferred to plastoquinone molecules QA and QB which accept two electrons and takes up two protein from the stroma. PQ carries electrons from PS II to cytochrome b/f complex containing FeS protein. This is thought to be the rate limiting step of electron transport. Electrons from PQ are taken up by Cyt b/f complex through FeS and releasing protons (2H+) to the lumen. The second mobile electron carrier plastocyanin (PC) takes the electrons and delivered to the photosystem I.(4) FLOW OF ELECTRONS FROM PS I TO NADP+ REDUCTASEA second excitation event within PS I leads to the transfer of electrons to the primary electron acceptor. The primary e- acceptor of PS I passes the photoexcited electrons to a second electron transport chain, which transmit then to ferredoxin, an iron containing protein. An enzyme called NADP reductase then transfer the electrons from Fd to NADP+ (oxidized form)(5) REDUCTION OF NADP+ TO NADPH+ H+This is the redox reaction that stores the high energy electrons in NADP+ to reduced it to NADPH + H+.NADP+ + 2H+ -> NADPH + H+Hydrogen ions are taken from stroma which is being pumped from thylakoid space to stroma by ATPase.PHOTOPHOSPHORYLATIONHydrogen ions are pumped into thylakoid space by cyt b/f and also 2H+ ions are collected there from photolysis of one water molecule. This large no. of H+ ions in thylakoid space compared to stroma, creates an electrochemical gradient, when these hydrogen ions flow out of the thylakoid space by way of a channel protein present in membrane called the ATP synthase complex, energy is prvided to it. The transport of 3 protons (H+ ions) through the ATPase complex are normally required to produce 1 ATP from ADP and inorganic phosphate Pi.ADP + Pi -> ATPThis is called chemiosmotic ATP synthesis because chemical and osmatic events join to permit ATP synthesis. The linear flow of electrons from H2O to NADP+, coupled to ATP syntheses is non-cyclic photophosphorylation because the electrons pass on to a terminal acceptor.In cyclic photophosphorylation the electrons are cycled from PS I back to PQ. So only ATP is produced but not NADPH + H+. This occurs under following conditions to meet increased ATP demand for e.g. CO2 fixation1. Protein synthesis2. Synthesis of starch

EVENTS OF LIGHT REACTION1. Photolysis of water.2. Reduction of NADP+ to NADPH + H+3. Synthesis of ATP by photophosphorylation.So during light reaction ATP and NADPH + H+ are produced which are used in Dark reaction, O2 is evolved as a by product.2. DARK REACTIONThe dark reaction consist of a series of light independent reactions which can proceed even in the absence of light. During dark reaction, energy is produced by ATP and NADPH+ H+ and CO2 is fixed in carbohydrates. This cyclic series of enzymatic catalyzed reaction in the stroma of the chloroplasts is called Calvin-Benson Cycle. During this cycle CO2 is reduced to triose-PO4 sugars, therefore this pathway is also known as C3 pathray (reductive pentose phosphate cycle) and the plants undergo this cycle are known as C3 plants. The calvin or C3 cycle is divided into 3 phases.CARBOXYLATION (CARBON FIXATION)The calvin cycle begins when a molecule of CO2 reacts with a highly reactive phosphorylated five carbon sugar named ribulase 1.5 bisphosphate (RuBP). This reaction is catalyzed by the enzyme ribulase biphosphate carboxylase or Rubisco (it is the most abundant protein in chloroplast). The product of this reaction is a highly unstable, six carbon intermediate that immediately breakdown into two molecules of three carbon compound called 3-phosphoglycerate (G3P).3CO2 + 3RuBP -> G3PREDUCTIONEach molecule of the PGA or G3P receives an additional phosphate from ATP of light reaction, forming 1,3-bisphosphoglycerate (G1,3P) which is then reduced to glyceraldehydes 3-phosphate (GA3P) and Dihydroxyacetone phosphate (DHAP) by NADPH+ H+GA3P and DHAP are intercovertible and the reaction don’t require any energy. These products are also formed during glycolysis and links dark reaction with sugar synthesis pathway.6G3P + 6ATP + 6NADPH + H+ -> 6GA3P + 6ADP + 6NADP+ + 6PiREGENERATIONThree carbon compounds are rearranged to form five carbon units ribulose 1,5-bisphosphate (RuBP), which is the primary carbon acceptors in the cycle.5 GA3P + 3ATP -> 3 RuBP + 3 ADP + 3PiAgain more molecules of ATP are used for phosphorylation of RuBP, which then starts the cycle again.CONCLUSIONFor every 3 molecules of CO2 entering the cycle and combining with 3 mole of RuBP (5C), six molecules of three carbon G3P is produced. Out of six G3P only one G3P molecule leaves the cycle and can be used for synthesis of glucose, starch, cellulose, sucrose or other compounds. The other 5 molecules are recycled to regenerate 5C RuBP’s three molecules, the CO2 acceptor.

CONSUMPTIONFor the net synthesis of one G3P molecule, the calvin cycle consumes a total of nine ATP’s and six NADPH + H+PHOTORESPIRATIONIn presence of light (photon), oxygen is taken up by RuBP and CO2 is evolved.RuBP + O2 -> PGA + Phosphoglycolate ® CO2It occurs when CO2 is deficient, Rubisco works like an oxygenase rather than carboxylase in presence of O2, produce phosphoglycerate (phosphoglyceric acid-PGA) and Phosphoglycolate, where phosphoglycolate rapidly breaks down to release CO2. Alternative mechanisms of carbon fixation in hot, arid climate.In hot temperature the concentration of CO2 begins to fall in leaves due to closing of stomata, increase yield of photosynthesis etc. These conditions in leaves may cause a wasteful process called photorespiration in which precious products are lost and less energy is generated. In certain plant species alternate mode of CO2 fixation have evolved even in very hot and arid environment.These two photosynthetic adaptations are1. C4 PHOTOSYNTHESIS (C4 PATHWAY)This process occurs in C4 plants. Those which prefer calvin cycle with an alternate mode of carbon fixation are known as C4 plants. CO2 reacts with PEP in presence of PEP carboxylase to produce oxaloacetate, a four carbon compound which converts into malate. Malate transfers from mesophyll cell to bundle sheath cell where it breaks down to pyruvate and releases CO2. This CO2 is fixed in calvin cycle by Rubsico and so the cycle continues.E.g. Family poaceae especially sugar cane, corn.2. CAMPlants of hot, arid environment, open their stomata during the night and close them during the day. Closing stomata during the day helps deserts plants to conserve water but it also prevents CO2 from entering the leaves. During the night, when their stomata are open, these plants take up CO2 and incorporate it into a variety of organic acids because of lack of energy (ATPs and NADPH+ H+). This mode of carbon fixation is called crassulacean acid metabolism (CAM). They store these organic acids in vacuoles. During day time organic acids release CO2 for dark reaction because light reaction can supply ATP and NADPH+ H+ on which the calvin cycle depends.E.g. Cactus, Pinapple, Succulent plants.CELLULAR RESPIRATIONAerobic breakdown of glucose molecules into CO2 and water with synthesis of ATP is called Cellular Respiration.C6H12O6 +6O2 -> 6CO2 + 6H2O + 673 Kcal/moleRespiration is an oxidation reduction process because the carbon of substrate, mostly glucose is oxidized to form CO2, while the atmospheric O2 is reduced to form the water.There are two types of cellular respiration.

(A) AEROBIC RESPIRATIONThe breakdown of sugar, in presence of oxygen [molecular O2] and release of carbondioxide and water with sufficient amount of energy. This type of respiration is known as Aerobic respiration, and the organisms performed this are known as Aerobes.(B) ANAEROBIC RESPIRATIONThe break down of sugar in absence of oxygen is known as Anaerobic respiration, and this type of respiration is performed by Anaerobs.E.g. Yeast, some bacteria, gut parasites (e.g. tapeworm). Some species of annelids, roots of plants growing in water logged area. Anaerobes are of two types. Those which never need of O2 at all are Obligate anaerobes. Those which respire aerobically but can also respire in absence of O2 are known as Facultative aerobes.CATEGORIES OF AEROBIC RESPIRATIONThe process of aerobic respiration is divided into three main categories.1. Glycolysis2. Kreb’s cycle3. ETC(1) GLYCOLYSISGlycolysis is the first and common step in both aerobic and anaerobic respiration. It consists of a complex series of enzymatically catalyzed reactions in which a 6 carbon molecule “Glucose” breaks down into 3 carbon “Pyruvic acid”. These reactions occur in Cytoplasm and doesn’t require oxygen. Following are the different steps of Glycolysis.(I) PHOSPHORYLATIONPhosphorylation is the addition of phosphate groups to the sugar molecules. Glucose is phosphorylated by a molecule of ATP to form an activated molecule, the glucose 6 phosphate. ATP is converted to ADP.(II) ISOMERIZATIONGlucose -6-phosphate is converted to fructose -6-phosphate, an isomer of it by an enzyme.(III) SECOND PHOSPHORYLATIONAnother molecules of ATP is invested which transfers its phosphate group to carbon no.1 of fructose –6-phosphate, forming fructose 1,6-bisphosphate and ADP.(IV) CLEAVAGEThe 6-carbon, fructose 1,6 bisphosphate molecule is break down into 2; three carbon molecules, 3-phosphoglyceraldehyde PGAL and dihydroxyacetone phosphate (DHAP). These two sugar molecules are isomers and are interconvertible. This is the reaction from which glycolysis derives its name. DHAP is converted to its isomer PGAL and then 2 PGAL will be converted to 2 pyruvic acid molecules. Since at this stage 2 ATPs are used, therefore this phase is known as Energy investment phase.In the subsequent reactions, energy is produced therefore this half is also

known as Energy yielding phase(V) DEHYDROGENATION (OXIDATION)In the next step, PGAL is acted upon by an enzyme dehydrogenase along with a co-enzyme nicotine amide adenine dinucleotide (NAD+), which convert PGAL into phosphoglyceric acid PGA or phosphoglycerate by the loss of two hydrogen atoms (2e- + 2H+). These H atoms are captured by NAD+. This is a redox reaction in which PGAL oxidized by removal of electrons and NAD is reduced by the gaining of electrons. Now phosphoglyceric acid PGA picks up phosphate group (Pi) present in cytoplasm and becomes 1,3-bisphosphoglyceric acid (DPGA)(VI) PHOSPHORYL TRANSFER1,3-bisphosphoglyceric acid loses its phosphate group to ADP forming ATP and 3-phosphoglyceric acid.(VII) ISOMERIZATIONThe PO4 group of PGA, attaches with carbon no,3 changes its position to carbon no.2 forming an isomer 1-phosphoglyceric acid.(VIII) DEHYDRATIONA water molecule is removed from the substrate and forming phosphoenal pyruvate (PEP)(IX) PHOSPHORYL TRANSFERADP removes the high energy PO4 from PEP producing ATP and Pyruvic acid. OVERALL REACTION of glycolysis can be summarized as Glucose + 2ADP + 2NAD+ -> 2 Pyruvic acid + 2ATP + 2NADH+ H+ + 2H2OENERGY YIELDSince when PGAL is produced, the cycle is counted twice because DHAP also converts into PGAL and enter the same cycle. 4ATP molecules are produced at Substrate level phosphorylation because PO4 groups are transferred directly to ADP from another molecule. 2 ATP are used in the first phase. Thus there is a net gain of 2 ATPs. 2 NADH+ H+ are produced and each gives 2 ATPs (a total of 6 ATPs). Therefore net production of ATP during glycolysis is 8 ATPsFATE OF PYRUVIC ACIDThere are 3 major pathways by which it is further processed under anaerobic conditions, pyruvic acid either forms, ethyl alcohol or lactic acid or produces CO2 and H2O from kreb’s cycle under aerobic conditions.FERMENTATIONFermentation the alternative term for Anaerobic respiration was used by W.Pasteur and defined as respiration in absence of oxygen (air). The production of ethyl alcohol from glucose is alcoholic fermentation and that of lactic acid is lactic acid fermentation.ALCOHOL FERMENTATIONEach pyruvic acid molecule is converted to ethyl alcohol also known as Ethanol in two steps. In the first pyruvic acid is decarboxylated to acetaldehyde under the action of enzyme.Pyruvic acid CH3.CO.COOH -> CH3CHO + CO2

In the next step NADH+ H+ reduces acetaldehyde to ethyl alcoholCH3.CHO + NADH+ H+ -> CH3.CH2OH + NAD+Ethyl alcohol is toxic, plants can never use it because it cannot be converted to carbohydrates or breaks up in presence of O2. When accumulation is more than tolerable limits, plants will be poisoned and subsequently they died.LACTIC ACID FERMENTATIONWhen NADH+ H+ transfer its hydrogen directly to pyruvic acid, it results in formation of lactic acid.Pyruvic acid + NADH + H+ -> CH3.CH.OH. COOHDuring extensive exercise such as fast running muscle cells of animals and man respire anaerobically. Due to inadequate supply of O2, pyruvic acid is converted to lactic acid. Blood circulation removes lactic acid from muscle cells. When lactic acid accumulates inside cells, it causes Muscle futigue. This forces person to stop work, until normal O2 levels are restored.ECONOMIC IMPORTANCE OF FERMENTATION1. It is the source of ethyl alcohol in wines and beers Wines are produced by fermenting fruits like grapes, dates etc. Beers are produced by fermenting malted cereals such as Barley.2. Yeast is used to prepare bread from wheat.3. Milk is converted to curd (yoghurt) by bacteria.4. Preparation of cheese and other dairy products.5. Production of lactic acid, propionic acid, and butanol.6. Flavour of pickles is due to lactic and acetic acid.7. Addition of lactic and acetic acids prevent foods from spoilage and also give sour flavours to yoghurt and cheese.8. Acetone is also formed as a by-product.(2) KREB’S CYCLEFORMATION OF ACETYL-COABefore entering the Kreb’s cycle, each molecule of pyruvic acid undergoes oxidative decarboxylation. During this process one of the three carbons of pyruvic acid molecule is removed to form CO2 by enzymatic reactions. Simultaneously pyruvic acid is oxidized and a pair of energy rich Hydrogen atoms are passed on to a H acceptor NAD+ to form NADH+H+. The remaining 2-carbon component is called acetyle which combines with coenzyme A to form an activated two carbon compound called acetyle CoA. “Acetyle CoA connects Kreb’s cycle with glycolysis.” For each molecule of glucose that enters glycoilysis, two molecules of acetyle CoA produced, which enter in a cyclic series of enzymatically catalyzed reactions known as Kreb’s Cycle, which occurs in Mitochondria.Pyruvic acid (3C) + CoA + NAD+ -> Acetyle CoA + CO2 + NADH+H+SERIES OF REACTIONS IN KREB’S CYCLESir Hans Kreb was working over these cyclical series of reactions therefore the cycle was given the name as Kreb’s cycle. The first molecule formed during the cycle is citric acid, so it is also called as “Citric Acid cycle.” This cycle is a multi

step process and the steps are given below:1. FORMATION OF CITRIC ACIDIn this first step of the Kreb’s cycle, bond between acetyl and CoA is broken by the addition of water molecule. The acetyl (2C) reacts with 4 carbon compound (oxalo acetic) acid to form 6-carbon compound, citric acid, and the CoA is set free. This citric acid possess 3 carboxyl groups, therefore the cycle is also recommended as Tricarboxylic Acid Cycle (TCA cycle).2. ISOMERIZATIONA molecule of water is removed and another added back so that cirtic acid is isomerized to isocitric acid through an intermediate, Cis-aconitic acid.3.FIRST OXIDATIVE DECARBOXYLATIONFirst time the sugar molecules are oxidized, therefore it is also called first oxidation of the cycle. Isocitric acid is oxidized yielding a pair of electrons (2H+) that reduces a molecule of NAD+ to NADH+H+. The reduced sugar molecule is decarboxylated with the removal of CO2. It now converts into a 5 carbon compound α-Ketoglutaric acid (αKG).4. SECOND OXIDATIVE DECARBOXYLATIONαKG is oxidatively decarboxylated. A CO2 molecule is lost. The remaining 4-C compound is oxidized by transfer of a pair of electrons (2H+) reducing NAD+ to NADH+H+. This 4-C compound accepts CoA forming succinyl CoA.5. SUBSTRATE LEVEL PHOSPHORYLATIONBond between succinyl and CoA is broken. CoA is replaced by PO4 group, which is then transferred to Guanosine diphosphate (GDP) to form Guanosine Triphosphate (GTP). GTP then transfers its phosphate group to ADP, forming ATP and with addition of 1 water molecule, succinic acid is formed.6. THIRD OXIDATIONWith loss of two electrons (2H+)succinic acid is oxidized to fumaric acid and FAD+ is reduced to FADH2.7. HYDRATIONOne water molecule is added to fumaric acid to convert it to Malic acid.8. FOURTH OXIDATION AND REGENERATION OF OXALO-ACETIC ACIDOxidation of malic acid leads to the production of 1 more NADH+H+ and oxaloacetic acid is regenerated.ENERGY YIELDGlucose molecule breaks down into 2 pyruvic acid molecules and each will enter the Kreb’s cycle.For each pyruvic acid molecule, 3CO2 molecules are produced, four NADH+H+ are produced and 1 FADH2.Pyruvic Acid + 3H2O + 4NAD+ + FAD+ -> 3CO2 + 4NADH+H+ + 1FADH2Four calculation of energy (ATPs) we will multiply the products with 2 as 2 acetyle CoA enters the Kreb’s cycle.Pyruvic Acid to Acetyl CoA…………..1NADH2 -> 3ATP x 2 = 6 ATPKreb’s Cycle………………………………..3NADH+H+ -> 9ATP x 2 = 18 ATP………………………………………………1FADH2 -> 2ATP x 2 = 4 ATP

………………………………………….Substrate Level Phosphorylation -> 1ATP x 2 = 2ATPTotal………………………………. = 30 ATPOVERALL ENERGY YIELD OF AEROBIC RESPIRATIONGlycolysis…………………………8ATPPyruvic Acid to Acetyl CoA…………..6ATPKreb’s Cycle……………………….24 ATPTotal……………………………..38 ATPBut actually 2 ATPs are utilizing in transporting cytoplasmic NADH+H+ to Mitochondria, which are produced during Glycolysis, so overall energy yield is only 36 ATPs.3. ELECTRON TRANSPORT CHAIN/ ETC OR ET SYSTEMThe last of all steps is ETC. It consists of a series of electron acceptors which are located in the cristae of mitochondria. In respiration there are 6 steps at which hydrogen atoms are released (one in glycolysis, 5 in Kreb’s cycle). A pair of hydrogen atoms are dissociated into a pair of electrons and a pair of protons.2H -> 2H+ + 2eThese electrons are accepted by Nicotinamide adenine dinucleotide (NAD) and Flavin Adenine Dinucleotide (FAD) from where they are passed along a chain of electron carriers such as cytochrome b, cytochrome c; cytochrome a, cytochrome a3.While passing from one carrier to another, these cytochromes are alternatively reduced and oxidized. During this, the energy released is used in the formation of ATP (adenosine triphosphate) from ADP and Pi. The final electron acceptor is atmospheric oxygen, which also picks up protons, and form the water molecule. The formation of ATP in mitochondria is called Oxidative Phosphorylation.From every NAD, 3ATPs and from 1 FADH2, 2 ATPs are produced.

Nutrition in PlantsCLASSIFICATION ON THE BASIS OF MODE OF NUTRITION Plants can be divided into two groups on the basis of their mode of nutrition.1. AUTOTROPHIC2. HETEROTROPHIC1. AUTOTROPHIC NUTRITION

DEFINITION“Autotrophic nutrition is the type of nutrition in which organic compounds are manufactured from available inorganic raw material taking from surroundings”.In autotrophic nutrition, the nutrients do not require to be pretreated or digested before taking them into their cells.TWO METHODS OF AUTOTROPHIC NUTRITIONOn the basis of source of energy, autotrophic nutrition can be sub-divided into following sub-types.(I) Phototrophic nutrition(II) Chemotrophic nutritionI. PHOTOTROPHIC NUTRITIONDEFINITION“The type of autotrophic nutrition is which organic molecules are manufactured from simple inorganic molecules by using light energy as a source is called Phototrophic Nutrition”.EXAMPLEa. Green Plantsb. Photosynthetic Bacteria(I-A) PHOTOTROPHIC NUTRITION IN GREEN PLANTSGreen plants are very prominent example of phototrophic nutrition. They prepare the food by the process of photosynthesis.RAW MATERIALThe raw material needed by these organisms are(1) CO2 AND H20They provide carbon, hydrogen and oxygen for the synthesis of organic molecules.(2) MINERALSThe minerals like Nitrogen, Phosphorus and Sulphur and Magnesium are also required.(3) GREEN PIGMENTSThe green pigments i.e. Chlorophyll a, b, or others are also required to absorb the energy from universal source of light.(4) LIGHTIn the presence of sun light nutrients are used to synthesis the energy rich compounded (CHO) This process is called “PHOTOSYNTHESIS”.This process can be represented by equation as follows.6CO2 + 12H2O -> C6H12O6 + 6O2 + 6H2O(I-B) PHOTOTROPHIC NUTRITION IN PHOTOSYNTHETIC BACTERIAPhotosynthetic bacteria are unique because they are the only organisms which are capable of synthesizing the carbohydrate food without chlorophyll “a”.DIFFERENCES BETWEEN PHOTOSYNTHETIC BACTERIA AND GREEN PLANTSPhotosynthesis in bacteria is different from green plants. Some differences are Photosynthetic bacteria usually grow in sulphide spring where H2S is normally present. Hydrogen is provided by H2S instead of H2O.

Free oxygen is not released as a by product in bacterial photosynthesis. The process takes place at low expenditure of energy.TWO TYPES OF PHOTOSYNTHETIC BACTERIAThere are two types of photosynthetic bacteria.(1) THOSE IN WHICH “S” IS RELEASED AS BY PRODUCTThese bacteria use H2S as donor of hydrogen. Light splits hydrogen sulphide. Hydrogen combines with CO2 to form H2O.2H2S + CO2 -> (CH2O)n + H2O + 2SEXAMPLESPurple Sulphur Bacteria ® which use BACTERIO CHLOROPHIL & CARETENOID as photosynthetic pigments.(2) THOSE IN WHICH “S” IS NOT RELEASED AS BY PRODUCTThese bacteria use H2S as Hydrogen donor where as sulphur is not the by product in their case.EXAMPLESPURPLE NON-SULPHUR BACTERIABROWN NON-SULPHUR BACTERIABoth of these contain “BACTERIO CHLORPHYLL” as photosynthetic pigments.(II) CHEMOTROPHIC NUTRITIONDEFINITION“The mode of autotrophic nutrition in which organic molecules are manufactured from simple inorganic molecules by using energy produced by the oxidation of certain inorganic substances such as ammonia, nitrates, nitrites, ferrous ions, H2S and etc. This type of nutrition is called CHEMOTROPHIC NUTRITION and process of manufacturing food is called CHEMOSYNTHESIS.”Mainly Bacteria areAMMONIA USING BACTERIAThey derive their energy by oxidation of Ammonia.NH4+ + O2 -> 2NO2 + 2H2O + 4H+ + energyBACTERIA CONVERTING NITRITES TO NITRATES2NO2 + O2 -> 2NO3- + energyIMPORTANCE OF CHEMOSYNTHETIC BACTERIAThe chemosynthetic bacteria that act on nitrogen compounds do play an important role in the maintenance of nitrogen balance in the life system.2. HETEROTROPHIC NUTRITION IN PLANTSDEFINITION“Plants which are not capable of manufacturing their own organic molecules entirely or partially depend for these organic molecular are called “HETEROTROPHIC PLANTS”CLASSIFICATION OF HETEROTROPHIC PLANTSOn the basis of type of organisms on which heterotrophic plants depend, they can be classified into following two classes.1. PARASITC PLANTS OR PARASITES2. SAPROPHYTIC PLANTS OR SAPROPHYTES1. PARASITESDEFINITION

“Those heterotrophic plants which depend on living plants and animals for their nutritional requirements are known as PARASITES.”TYPES OF PARASITESParasitic plants can be divided into following types.A. Obligate or total parasites.B. Facultative or partial parasites.1.A TOTAL PARASITESDEFINITIONThose parasites which depend for their nutrition entirely on other living organismsCLASSIFICATION OF TOTAL PARASITIC ANGIOSPERMSTotal or obligate parasitic angiosperms are broadly classified into1. Total stem parasite2. Total root parasite1. TOTAL STEM PARASITESDEFINITION“Those parasitic plants which depend entirely on the stems of other plants are called “Total stem Parasites”EXPLANATIONThese plants send HAUSTORIA (specialized structures for absorbing nutrients in parasitic plants) inside the tissue of host. The xylem of parasite comes in contact with xylem of host and phloem of parasite to phloem of host. Through xylem it sucks the water and nutrients, through phloem prepared organic material. The host plant eventually dies off due to exhaustion.EXAMPLECUSCUTA (AMER-BAIL)2. TOTAL ROOT PARASITESDEFINITION“Those parasitic plants which suck their nutritional requirements from the roots of host are called “Total root parasites”.EXAMPLESOROBANCHE -> attacks the roots of the plants belonging to families Cruciferae and SolanaceaeCISTANCHE -> Parasitizes on the roots of Calatropis.STRIGA -> Found as parasite on the roots of sugar cane(1.B)PARTIAL PARASITESDEFINITION“Those parasite plants which depend for their nutritional requirements partially on other living organisms are called Falcultave or partial parasites.”

CLASSIFICATION OF PARTIAL PARASITIC ANGIOSPERMSPartial parasitic angiosperms can be broadly classified into1. PARTIAL STEM PARASITE2. PARTIAL ROOT PARASITE1. PARTIAL STEM PARASITESDEFINITIONThose partial parasites whose haustoria penetrate in the stem of the host and suck their nutrition from vascular tissues of stem are called PARTIAL STEM

PARASITE

EXPLANATIONLORANTHUS, is a partial stem parasite. It has thick green leaves, a woody stem and elaborated haustorial system. It can manufacture some of its food with the help of nutrients and water absorbed from host plants. The seeds get stuck upto the stem of host plant and germinates sending its haustoria in the tissues of the host.EXAMPLESLORANTHUS -> found on shrubs, roseaceous tree, Bauhinia and mangoVISCUM -> produce haustorial branches for an internal suckling system.CASSYTHA FILLIFORMIS -> found in tropics2. PARTIAL ROOT PARASITESEXAMPLEThe examples of this category are rare.One important example isSANDLE WOOD TREESAPROPHYTESDEFINITION“Those plants which depend for their nutrition on dead or rotten organic remains of plants or animals are called as SAPROPHYTES”

or

“Plants which break up complex dead food material into simple compounds and use them for their growth and development are called as SAPROPHYTES.”TYPES OF SAPROPHYTESSaprophytes can be divided into two types:1. Total Saprophytes2. Partial Saprophytes1. TOTAL SAPROPHYTESDEFINITION“Those plants which depend entirely for their nutrition on dead organic matter are called Total Saprophytes.2. PARTIAL SAPROPHYTESDEFINITION“Those plants which depend partially on dead organic matter are called Partial Saprophytes.”EXAMPLES OF SAPROPHYTESThere are some examples of Saprophytes among flowering plants.1. Neothia (bird’s net or orchid)2. Monotrapa (Indian Pipe)In both of these cases, the roots of plant form a Mycorhizzal Association with fungal mycelium to help in absorption process.SPECIAL MODE OF NUTRITIONCARNIVOROUS OR INSECTIVOROUS PLANTSDEFINITION“The plants which have as their prey, insects and small birds are called

Carnivorous plants. It is a special mode of nutrition in partially autotrophic and partially heterotrophic plants.”EXPLANATIONPartially autotrophic and partially heterotrophic plants are carnivorous, which possess the green pigments and can manufacture CHO but are not capable of synthesizing nitrogenous compounds and proteins. For their nitrogen requirement, carnivorous plants have to depend on insects, which they catch and digest by specific devices developed in them. J.D. Hooker suggested that the digestion of carnivorous plants is like that of animals.COMMON AREAS WHERE THESE PLANTS GROWThese plants commonly grow in areas where nitrogen is deficient due to unfavourable atmosphere for nitrifying bacteria but favourable atmosphere for denitrifying bacteria.SOME COMMON EXAMPLES1. PITCHER PLANTIn Pitcher plant leaf is modified into pitcher like structure which is insect trapping organ.EXAMPLESCommon examples are :NepenthesSarraceniaCephalotusNeliamphoraDarling tonia2. DORSERA INTERMEDIA OR SUNDEWThis plant has half a dozen prostrate radiating leaves, which bear hair like tentacles each with gland at its tip. The insects attracted by plant odour are digested.3. DIONAEA MUSCIPULA OR VENOUS FLY TRAPMost well known of all carnivorous plants. It has a resette of prostrate radiating leaves with inflorescence in the centre. The petiole of leaf is winged and lamina has two halves, with mid-rib in the centre. Each half has 12-20 teeth. In the centre of dorsal surface of lamina are numerous secretory glands, three hairs projecting out, which are sensitive to touch.4.ALDROVANDA (WATER FLY TRAP)It is a root less aquatic plant with floating stem. It has ressettes of modified leaves, which have two lobed mobile lamina having teeth at the margin and sensitive jointed hairs and glands on the surface.5. UTRICULARIA OR BLADDER WORTIt is a root less plant having branched slender stem. Leaves are also much divided and some leaflets are modified into bladder like traps of about 1/16 to 1/8 inches in diameter.

Human Digestive SystemDIGESTION “It is the process by which large complex insoluble organic food substances are broken down into smaller simpler soluble molecules by the help of enzymes”.Digestion in man is mechanical (break down) as well as chemical (enzymatic hydrolysis)NUTRITIONHETEROTROPHIC, i.e. man is dependent upon ready made food.TYPE OF DIGESTIONEXTRACELLULAR, i.e. digestion takes place outside the cells but within GIT.TYPE OF DIGESTIVE SYSTEMTUBE LIKE DIGESTIVE SYSTEM, i.e,Digestive cavity is separated from body cavity.It has both openings, mouth and anus.“Complete” digestive sytemThis one way tube is known as GASTRO-INTESTINAL TRACT (GIT)ORGANS OF GASTRO-INTESTINAL SYSTEMThe adult digestive system is a tube approximately 4.5m (15ft) long and comprises of(A) G I T1. MOUTH2. ORAL CAVITY -> TEETH, TONGUE3. PHARYNX4. OESOPHAGUS5. STOMACH6. SMALL INTESTINE -> DUODENUM, JEJUNUM, ILEUM7. LARGE INTESTINE -> CAECUM, RECTUM, COLON8. ANUS -> PAROTID(B) ASSOCIATED GLANDS1. SALIVARY GLANDS -> SUBLINGUAL, SUBMANDIBULAR2. LIVER3. PANCREAS(1) MOUTHThe anterior or proximal opening of gut, which is bounded anteriorly by lips. It opens into oral cavity.FUNCTION1. Lips close the mouth.2. Lips also help in ingestion.(2) ORAL CAVITY

It is a wide cavity supported by bones of skullBOUNDARIES Cheeks form side walls. Tongue forms floor Palate forms roof Jaws form roof boundary of mouth.+ JAWSUpper jaw is fixed while lower jaw is moveable. Both jaws bear teeth.CONTENT OF CAVITYTeeth and Tongue+ TEETH“The hard calcified structures, meant for mastication (chewing)”NUMBER OF SETSHumans have 2 sets of teeth ® DIPHYODONT(1) DECIDUOUSThe 20 teeth of first dentition, which are shed and replaced by permanent teeth.(2) PERMEMANTThe 32 teeth of second dentition, which begin to appear in human at about 6 year of age. It consisting of 8 incisors, 4 canines, 8 premolars and 12 molars.+ Molars are absent in deciduous set.HETERDONT They are embedded in gums -> THECODONTSTRUCTURE OF A TOOTHEach tooth consist of 3 parts1. CROWN2. NECK3. ROOTFUNCTIONS1. Incisors are cutting and biting teeth. Their flat sharp edges cut food into smaller pieces.2. Canines are pointed teeth and poorly developed in humans. They are used in tearing, killing and piercing the prey.3. Premolars and Molars are grinders and used for crushing the food.4. Mastication increases surface are of food for action of enzymes.5. If one attempt to swallow a food particle too large to enter ocsophagus, it may block the trachea and may stop ventilation.“DENTAL DISEASES”PLAQUE“A mixture of bacteria and salivary materials”OR“A soft thin film of food debris, mucin and dead epithelial cells deposited on teeth, providing medium for growth of bacterias”Plague plays an important role in development of dental caries, periodontal and gingival disease. Calcified plaque forms dental calculus.PERIODONTAL DISEASESAccumulation of plaque causes inflammation of gums. Continuous inflammation may spread to the root of tooth and destroy peridental layer. Eventually tooth

becomes loose and falls off or may have to be extracted.DENTAL CALCULUSPlaque combine with certain chemicals in saliva which become harden and calcified forming deposits of calculus which cannot be removed by brushing.DENTAL CARIESWhen bacteria of plaque converts sugar of food into acid, the enamel (hardest substance of body, covers dentin of crown of teeth) is dissolved slowly. When dentine and pulp are attached, produce toothache and loss of teeth.FACTOR CAUSING DENTAL CARIES Prolonged exposure to sugary food stuff. Disturbance of saliva composition Lack of oral hygiene Low levels of fluoride in drinking H2OPREVENTION Add ‘flouride’ in drinking H2O or milk Take ‘flouride’ tablet Use ‘flouride’ tooth paste.TONGUETongue is a muscular fleshy structure forming floor of oral cavity. Tongue has a root a tip and a bodyIt is attached posteriorly and free anteriorlyTASTE BUDS Taste buds respond to sweet, salt, acid and bitter taste, only when these substances are dissolved in H2O of saliva. Taste buds are most numerous on sides of vallate papillae. They are absent on mid dorsal region of oral part of tongue.TONGUE PAPILLAEPapillae are projections of mucous membrane which gives characteristic roughness to the tongue. These are of 3 types VALLATE PAPILLAE FUNGIFORM PAPILLAE FILLIFORM PAPILLAEFUNCTIONS1. Its function is ‘Spoon-like’.2. It mixes the masticated food with saliva3. It helps in swalloing4. It helps in sucking and testing food.SALIVARY GLANDS3 pairs of salivary glands.(1) PAROTIDLies at base of pinnae.It is supplied by IX cranial nerve.

(2) SUB LINGUALLies at base of tongue.Supplied by VII cranial nerve.(3) SUB MANDIBULARLies at base of lower jaw.Supplied by VII cranial nerveFUNCTIONThese three pairs produce about 1.5dm3 of saliva each day.These glands are supplied by Parasympathetic Nervous System. Fibers of parasympathic N.S lie in Cranial nerves. These nerves increase their secretion.SALIVAIt is a watery secretion containing 95% H2O, some mucous, amylase and Lysozyme enzyme. Salivation is brought about by “Parasympathetic Nervous System.” Saliva is secreted in response to the sight, thought, taste or smell of food.FUNCTIONS1. Mucous of Saliva moistens and lubricates the food particles prior to swallowing.2. Salivary Amylase or Ptylin begins digestion of starch, first to dextrins and then to maltose (dissacharide).3. Lysozyme destroys the oral cavity pathogen bacteria. It has a cleansing action.4. Water in Saliva, dissolve some of the molecules in food particle then they react with chemo receptors in taste buds, giving sensation of taste, hence, the H2O enables taste buds to respond.5. Saliva is fully saturated with calcium and this prevents decalcification of teeth.6. Saliva makes speech possible by moistening the mouth; it is not possible to talk if the mouth is dry.7. It acts as a lubricant and enables a bolus (a rounded mass of semi-solid, partially digested food particles stick together by mucus) to be formed. The tongue pushes bolus into pharynx.3. PHARYNXThe musculo-membranous passage between mouth and posterior nares and the larynx and oesophagus.OPENINGSIt contains opening of oesophagus, glottis, Eustachian tube and internal nostrils.PARTS OF PHARYNXNASOPHARYNNXThe part above the level of soft palate is NASOPHARYNX, which communicates with auditory tube.OROPHARYNXIt lies between soft palate and upper edge of the epiglottis.HYPOPHARYNXIt lies below the upper edge of epiglottis and opens into larynx and oesophagus.

FUNCTION -> SWALLOWINGSwallowing in its initial stages is voluntary but involuntary afterwards.MECHANISM1. As the bolus of food moves into the pharynx, the soft palate is elevated and lodges against the back wall of pharynx sealing the nasal cavity and preventing food from entering it.2. The swallowing center inhibit respiration, raises the larynx and closes the glottis (opening between vocal cords), keeping food from getting into trachea.3. As the tongue forces the food further back into the pharynx, the bolus tilts the epiglottis backward to cover the closed glottis.4. This pharyngeal act of swallowing lasts about 1 second.4. OESOPHAGUSThis is a narrow muscular tube of about 25cm long. It connects pharynx to stomach. It passes through the thoracic cavity and penetrates the diaphragm, then it joins the stomach a few cms below the diaphragm.MUSCLES OF OESOPHAGUSUpper-one third is surrounded by skeletal muscles.Lower two-third is surrounded by smooth muscles.SPHINCTERS (MUSCULAR VALVES)1. Skeletal muscles, just below pharynx surrounding oesophagus form Upper Oesophageal Sphincter.2. Smooth muscles in last 4 cm of oesophagus forms Lower Oesophageal Sphincter. It seals the exit of food.FUNCTIONIt conveys the food or fluid by Peristalsis.PERISTALSISAlternate rhythmic contraction and relaxation waves in the muscle layers surrounding a tube are called Peristaltic Waves.It is the basic propulsive movement of GIT.STIMULUSDistention of oesophagus.TIMINGAn oesophageal peristaltic wave takes about ‘9 sec’ to reach stomach. Bolus is moved toward stomach by progressive peristaltic wave which compresses the lumen and forces the bolus ahead of it.ANTI-PERISTALSISPeristalsis in opposite direction, i.e. from stomach towards pharynx.STIMULUS Early stages of GIT irritation. Over distention.VOMITINGAnti peristalsis begins to occur, some minute before vomiting appears. The initial events of anti peristalsis may occur repeatedly without vomiting, called RETCHING. 1. Vomiting begins with a deep inspiration, closure of glottis and elevation of soft palate.2. Abdominal and thoracic muscles contract, raising intradominal pressure.3. Stomach is squeezed, lower oesophageal sphincter relaxes allowing

expulsion of stomach content into oesophagus in form of VOMITUS.5 OESOPHAGUSStomach is a hollow, muscular, distensible bag like organ.LOCATIONLying below the diaphragm on the left side of abdominal cavity.STRUCTUREIt has 3 regions.1 CARDIAC REGIONThis is the anterior region which joins the oesophagus through a cardiac sphincter. It has muscous glands which helps in lubrication of food.2 BODYThe middle portion is body of stomach. The part to the left and above the entrance of oesophagus is called FUNDUS of stomach. Body of stomach contain gastric glands. Gastric glands contain 3 types of cells.MUCOUS CELLS These cells are present at opening of gastric glands and secrete mucous. It lubricates the food and passage. It also protects the epithelium from self digestion by pepsin.OXYNTIC / PARIETAL CELLS They lie deeper within the glands and secrete dilute HCl having a pH of 1.5 – 2.5. Kills microbes Solublization of food particles. Activate the inactive enzyme pepsinogen into Pepsin.CHIEF CELL / ZYMOGEN CELLS Deeper in the glands and secrete enzyme precursor Pepsinogen. After converting into Pepsin, it acts upon proteins and convert them into short chain polypeptides, Peptones.The collective secretion of the above mentioned 3 cells is called as GASTRIC JUICEPYLORIC REGIONThe posterior region is the terminal narrow pyloric region or Antrum. It opens into duodenum through pyloric sphincter / pylorus.ITS SECRETION -> GASTRINThis region does not secrete acid. It secretes mucous, pepsinogen and a hormone GASTRIN. Endocrine cells which secrete GASTRIN are scattered throughout epithelium of antrum.STIMULUSPartially digested proteins.ACTIONActivate gastric glands to produce gastric juices.“RENIN”-ADDITIONAL ENZYME IN INFANTIn infants, RENIN is secreted which curdles the milk.FUNCTION OF STOMACH(1) STORAGE OF FOODPylorus acts as a valve and retain food in the stomach for about 4 hours.

Periodic relaxation of pylorus releases small quantities of chyme into duodenum.(2) MECHANICAL DIGESTIONThe weak peristaltic waves also called mixing waves move along the stomach wall once every 20 seconds. These waves not only mix the food with secretions but also move mixed contents forward.(3) CHEMICAL DIGESTIONGastric juice converts food to a creamy paste called CHYME.6. SMALL INTESTINEThe small intestine is a coiled tube approximately 6 meters long and 2.5 cm wide, leading from stomach to large intestine. It fills most of the abdominal cavity.DIVISIONSThere are 3 divisions.A. DUODENUMIt begins after pyloric stomach and ends at jejunum. Its length is about 30cm.SECRETIONPancreatic juice from pancreas by pancreatic duet and bile from gall bladder by common bile duct act on chyme from stomach. Both ducts open via a common opening in duodenum.BILESYNTHESIS, STORAGE AND SECRETIONBile is made in liver and enters the duodenum via the bile duct. It stores in gall bladder.COLOURBile is yellow in colour but changes to green due to exposure to air.CONSTITUENT Water. Bile Salts+ BILE SALTSThese are sodium salts of compounds of cholestrol. NaHCO3 is also present which neutralizes the acidity of gastric juice and make the chyme alkaline.The main bile salts are for emulsification of fats.EMULSIFICATION Break down of large fat particles into small droplets so that they can mix well with H2O to form emulsions.+ BILE PIGMENTSBILIRUBIN and BILIVERDIN are excretory products formed by breakdown of haemaglobin of worn out RBCs in the liver.ACTION OF ‘CHOLECYSTOKININ (CCK)’CCK is a hormone and produced by cells of small intestine.STIMULI FOR HORMONE RELEASEFatty food in duodenum.ACTIONCCK is released in blood and reaches to gall bladder and causes it to contract. Due to contraction of gall bladder, bile enters the duodenum.‘PANCREATIC JUICE’Pancreatic juice is produced in pancreas by its exocrine function and secreted

via pancreatic duct. It is a colourless fluid.ACTION OF SECRETINSecretion is also a hormone and produced by cells of small intestine.STIMULIAcid (HCl) carried with chyme in small intestine.ACTIONIt increases the secretion of pancreatic juice and also increases bicarbonate secretion in bile.CONSTITUENTS(1) TRYPSIN (PROTEASE)It is secreted in an inactive form called Trypsinogen which is activated by action of an enzyme produced by duodenum called enterokinase.ACTIONBreak proteins and long chain polypeptides into small peptide fragments.(2) CHYMOTRYPSIN (PROTEASE)It is also secreted in inactive form, Chymotrypsinogen which is converted into chymotrypsin by action of Trypsin.ACTIONConverts casein (milk proteins) into short chain peptide.(3) AMYLASEIt is similar to salivary amylase. It acts on polysaccharides (Glycogen and Starch) and convert them into maltose (a disaccharide).(4) LIPASEIt acts on emulsified fat droplets. It splits off lipid into fatty acid and glycerol, hance the digestion of fat is completed in duodenum.(B) JEJUNUMIt extends from duodenum to illeum. It is 2.4 meters long. Here the digestion of food is completed.COLLECTION OF PEPTIDASES, EREPSINPeptidases complete the breakdown of polypeptide into amino acids.NUCLEOTIDASEIt converts nucleotides into nucleoside. End products of digestion, i.e, monosaccharide and A.As are liberated in lumen of small intestine for absorption in ileum.(C) ILEUMIt is the last and longest part of small intestine. Its length is about 3.6 meters long. It contains digested food in true solution form.STRUCTUREThe inner wall (Mucosa and Submucosa) of small intestine is thrown into various folds. These folds have finger-like microscopic projections called villi.VILLIEach villus is lined with epithelial cells having microvilli on their free surfaces.Their walls are richly supplied with blood vessels and lymph vessels called Lacteals. Some smooth muscles are also present in villi.MECHANISM OF ABSORPTIONMajor function of ileum is absorption of digested food, which is facilitated by highly folded inner wall of intestine with villi on their surfaces.

This increases the absorptive area. Villi are able to move back and forth due to muscle fibers in them. The monosaccharide and A.As are absorbed into blood capillaries by Diffusion or Active Transport. Fatty acid and glycerol enter epithelial cells of villi, covert into triglycerols and enters Lacteals and pass into blood stream.BLOOD DRAINAGE OF INTESTINEAll capillaries converge to form hepatic portal vein, which delivers absorbed nutrients to liver.7. LARGE INTESTINESmall intestine opens into large intestine, which is a large diameter tube about 6.5 cm. It is not coiled by relatively has 3 straight segments.+ Caecum+ Colon+ Rectum+ CAECUMCaecum is a blind ended pouch placed in the lower right side of abdominal cavity. It gives a 10cm long finger like projection, Appendix. Appendix is a vestigial organ, i.e. an organ present in rudimentary form and has no function but has well developed function in ancestors.FUNCTIONSymbiotic bacteria, present in caecum, help in digestion of cellulose, which is not digested by man, as enzyme for digestion is absent.+ COLONColon is longest part and has 3 regions :+ Ascending colon+ Transverse Colon+ Descending Colon-> SIGMOID COLON is terminal part of Descending Colon.FUNCTIONInorganic salts, water and mineral absorbed in colon. Some metabolic waste products and excess calcium of body as salts are excreted into large intestine. Each day 500 ml of intestinal content enter the colon and during its passage the amount reduced to 150 ml due to absorption of H2O.+ RECTUMRectum is last portion, it stores faeces for some time.When the faeces enter into rectum, it brings about a desire for defecation. The process by which faeces passes out is called Egestion.SYMBIOTIC BACTERIAMany symbiotic bacteria in large intestine provide the body with a source of vitamin and A.As, especially vitamin B complex and K, which are absorbed in blood stream. Administration of Broad-spectrum antibiotics destroys these bacteria and a vitamin deficiency results, which is then make up by vitamin intakes.8. ANUSExternal opening of digestive system is ANUS.SPHINCTERS

Two sphincters surround the anus:+ Internal Sphinter -> made up of smooth muscle and under Autonomic control (involuntary control).+ Outer Sphincter -> made up of skeletal muscle and under Somatic Control (voluntary control).FAECUSFaecus consists of:Dead bacteria, cellulose, Plant fibers, dead mucosal cells, mucous, cholesterol, bile pigment derivatives and H2O.(DIAGRAM “DIGESTIVE SYSTEM” FROM BOOK XI)9. LIVERLiver is the largest organ and gland of body. It weighs about 1.5 kg . It is also called ‘HEPAR’.COLOURIt is reddish brown in colour.LOCATIONIt lies below the diaphragm on right side.LOBES OF LIVERLiver has 2 lobes, i.e. Right and Left. Left is further divided into two lobes.FUNCTIONS OF LIVER‘AS A METABOLIC FACTORY’It maintains the appropriate level of nutrients in blood and body. It is performed in 3 ways.A. GLUCOSE METABOLISM1. Additional (Surplus) Glucose is converted into Glycogen by action of INSULIN after every meal. This is called Glycogenesis.2. Glycogen is splitted into Glucose for body needs. This is called Glycogenolysis.3. New glucose for body requirement is formed by non-carbohydrate compounds. This is called Gluconeogenesis.B. A.AS METABOLISMA.As are also stored after deamination (removal of NH2 group), which forms Urea.C. FATTY ACID METABOLISMIt also processes F.As and stores the products as Ketone Bodies, which are released as nutrients for active muscles.‘AS A DETOXIFICATION CENTER’Poisons and toxic substances, which can harm the body, are degraded into harmless compounds. It excrete out bile pigments and waste products.‘AS A STORAGE ORGAN’It stores vitamins and also produces proteins and coagulating factors of blood.GALL BLADERIt lies on undersurface of liver, a pear shaped organ.FUNCTIONIt concentrates and stores the bile secreted by liver.BILIARY TRACFTTwo hepatic ducts from liver bring bile and join the cystic duct from gall bladder. This form common bile duct, which joins Pancreatic duct coming from

pancreas bringing pancreatic juice. These 2 ducts open into duodenum at same opening.10.PANCREASA large elongated gland situated transversely behind the stomach, between spleen and duodenum.PARTS OF PANCREASHEADIt is the right extremity and directed downwards.TAILLeft extremity is transverse and terminates close to spleen.BODYThe main portion in middle.DUCTPancreatic duct opens into duodenum with common bile duct and delivers pancreatic juices.WORKING AS A GLANDIt works both as an endocrine and exocrine gland.ENDOCRINE PANCREASEndocrine part consists of ISLETS OF LANGERHANS.The islets contain.α cell (ALPHA)Produce GLUCAGON which increases blood glucose level.β cell (BETA)Produce INSULIN which reduces blood glucose level.Δ cell (DELTA)Produce Somatostatin (SS) which inhibit the release of many harmones.P P cellsSecrete pancreatic polypeptide.EXOCRINE PANCREASEThe exocrine part consists of pancreatic acini. Acini are secretory unit that produce and secrete pancreatic juice into duodenum which contain enzymes essential to digestion.DISORDERS OF ‘GIT’(1) DIARRHOEAAbnormal frequency and liquidity of fecal discharges. It is the rapid movement of fecal matter through large intestine.CAUSESENTRITISIt may be caused by infection of intestinal wall (mucosa) by a virus or bacteria. Due to infection, mucosa becomes irritated and motility of intestinal wall increases.CHOLERACholera is a bacterial disease caused by VIBRIO CHOLERA. It can cause diarrhoea. It causes extreme amount of HCO3- (bicarbonates ion) and Na and H2O to be secreted in faeces. It may causes death.PSYCOGENIC DIARRHOEAIt is caused by nervous tension. In the young and elderly, diarrhoea may lead to a serious depletion of H2O and inorganic salts.

(2) DYSENTARYAcute inflammation of intestines especially of the colon.SYMPTOMSPain in abdomen, tenesmus (straining), frequent stool containing blood and mucus.CAUSESPROTOZOA. (like amoebic dysentery) PARASITIC WORMS. BACTERIA. (like bacillary dysentery) CHEMICAL IRRITANTS.(3) CONSTIPATIONInfrequent or difficult evacuation of faeces. OR Slow movement of faeces through large intestine.Faeces becomes hard due to long time available for H2O absorption.CAUSEIrregular bowel habits that have developed through a life time of inhibition of normal defection reflaxes.TREATMENT Laxatives are used Substance which hold H2O with them(4) PILESAlso called HAEMORRHOIDS Varicose dialatation of veins occurring in relation to anus, resulting from a persistence increase in pressure.EXTERNAL PILESVenous dialatation covered with modified anal skin.INTERNAL PILESDilatation of veins covered by mucous membrane.CAUSECONSTIPATIONThe pressure exerted to defecate stretches skin with vein and causes dilation.PREVENTIONCan be avoided by regular habit of defecation and by use of fiber diet.(5) DYSPEPSIAImpairment of the power or function of digestion, usually applied to epigastria discomfort following meals.CAUSEMay be due to peptic ulcer.SYMPTOMS Heart burn. Flatulence (distended with gas) Anorexia, nausea, vomiting with or without abdominal pair.FUNCTIONAL / NON-ULCER DYSPEPSIADyspepsia in which symptoms resemble those of peptic ulcer, although no ulcer is detectable. It is caused by disturbance in moter function of alimentary tract.(6) PEPTIC ULCERSince pepsin, is a protein digesting enzyme, it may digest the stomach wall, the

first part of duodenum or rarely lower part of oesophagus where stomach juices frequently refluxes. This condition is called Peptic Ulcers. GASTRIC ULCERS DUODENAL ULCERSCAUSES Excessive secretion of acid and pepsin. It may be hereditary. Psychogenic factors.COMPLICATIONSComplications of peptic ulcers are perforation, haemorrhage and obstruction. INVESTIGATIONS1. Acid output of stomach is studied.2. Ulcers cavity may be shown up on X-rays after ingestion of insoluble barium sulphate (Barium meal).3. It may be seen using optical instrument passed down through oesophagus (endoscopy)(7) FOOD POISONINGAlso called GASTRO-ENTRITISCAUSESINFECTIONBy bacteria, virus, protozoa. ‘Salmonella’ species are very common.NON-INFECTIOUSAllergy, irritating food or drink.SYMPTOMSVomiting and diarrhoea within 48 hours.(8) MAL NUTRITIONAny disorder of nutrition due to unbalanced diet or due to defective assimilation or utilization of foods.An organism may be deficient or may receives excess of one or more nutrients for a long period of time.UNDER NUTRITIONDeficiency is known as under-nutrition. It is most common problem of under developed countries.OVER NUTRITIONExcess is known as over-nutrition. Obesity with heart problems and reduced life expactency are its symptoms and are more common in developed countries.(9) OBESITY AND OVER WEIGHTIncrease in body weight beyond the limitation of skeletal and physical need as the result of accumulation (excessive) of fat in the body.It is the most common nutritional disorder. It is most prevalent in middle age. It may be hereditary or family tendency over weight results in rate of mortality.(10) ANOREXIA NERVOSALoss or lack of appetite for food is called Anorexia.ANOREXIA NERVOSAAn eating disorder affecting young females, characterized by refusal to maintain a normal minimal body weight, intence fear of gaining body weight, intense fear of gaining weight or becoming obese. Sometimes accompanied by

spontaneous or induced vomiting.(11) BULIMIA NERVOSAExclusively found in women and the age of onset is slightly older than for anorexia.Recurrent episodes (bouts) of binge (uncontrolled) eating. Lack of self control over eating during binges.Attacks occur twice a week and involve rich foods such as cakes and chocolates and dairy products

Digestive System of CockroachNUTRITION OMNIVOROUS, i.e. It can eat any kind of organic matter. They search their food by antennae.TYPE OF DIGESTIVE SYSTEMTABULAR DIGESTIVE SYSTEM, i.e. straight slightly coiled dig tube, open at both ends, complete dig. system.ORGANS OF DIGESTIVE SYSTEM+ ALIMENTARY CANALIt is divisible into 3 parts1. FORE GUT / STOMODAEUM MOUTH BUCCAL CAVITY OESOPHAGUS CROP GIZZARD2. MIDGUT / MESENTERON / VENTRICULUS HEPATIC CAECA3. HIND GUT / PROCTODAEUM ILEUM COLON RECTUM ANUS+ ASSOCIATED GLAND SALIVARY GLANDS

1.FORE GUTMOUTHIt lies at base of pre-oval cavity which is bounded by mouth part.LABRUM / UPPER LIPAppendage of 3rd head segment.MANDIBLESAppendage of 4th head segment. They help in masticationMAXILLAEAppendages of 5th head segment. They pick up and bring food.LABIUM / LOWER LIPAppendages of 6th head segment.BUCCAL CAVITYThe mouth opens into buccal cavity which is short and receives the common duct of salivary glands.Saliva cantain ‘AMYLASE’ which act upon carbohydrates.OESOPHAGUSBuccal cavity opens into pharynx which in turn opens into oesophagus which is a long and thin tube lying in thorax.CROPIt is a large thin walled and pear shaped structure meant for storing food.GIZZARDCrop opens into thick walled, rounded gizzard with muscular chitins lining which is internally produced six teeth for grinding and straining the food.2. MID-GUTIt is narrow, short and tubular portion originate from gizzard. At beginning it receives eight hepatic caeca hanging in haemocoel (body cavity filled with white colour blood), ending blindly but opening in gut.ENZYMES FROM HEPATIC CAECAThey are lined by glandular cells, which secrete enzymes.Enzymes from hepatic caeca and mid-gut flow back into crop where digestion takes place.ENZYMES1. PEDTIDASES AND TRYPSIN LIKE ENZYME -> digest proteins.2. AMYLASES -> complete digestion of starches3. LIPASE -> digestion of fats.Digested food form a bolus and enclosed in a thin chitinous tube secreted by stomodael valve of gizzard. This covering is called PERITROPHIC MEMBRANE.It is permeable to enzymes and digested food. This membrane protects the lining of mid gut from damage by hard indigestible components of food.Digested food is absorbed in mid gut.3. HIND-GUTIt has a cuticular ectodermal lining.ILEUMShort, narrow and muscular ileum. The beginning of ileum is marked by 60-70 fine and long, greenish yellow MALPHIGIAN TUBULES. (excretory in function)COLONColon is long, wider and coiled portion of hind gutRECTUM

Rectum is broad last part of hind gut. It absorbs H2O and conserves the much needed H2O from undigested food before expelling out the faeces.ANUSAnus is the last opening of digestive system by which hind gut opens to outside.SALIVARY GLANDSSalivary glands are 2 in number. each present on the sides of oesophagus. Saliva contain amylase for digestion of carbohydrates

Gaseous ExchangeRESPIRATORY ORGANS OF COCKROACH TRACHEAL SYSTEM Cockroach has evolved a special type of invaginated respiratory system called Tracheal system, especially adopted for terrestrial mode of life and high metabolic rate of insects.STRUCTURAL CONSTITUENTS OF TRACHEAL SYSTEM1. TRACHEA2. SPIRACLES3. TRACHEOLES1.TRACHEATracheal system consists of number of internal tube called Trachea which are the connection between the spiracles and tracheal fluid.2. SPIRACLESLaterally, trachea open outside the body through minute, slit like pores called as spiracles.There are 2 pairs of spiracles on lateral side of cockroach.2 lie in thoracic segments and 8 in first abdominal segments.3. TRACHEOLESOn the other side, trachea ramify throughout the body into fine branches or tracheols.Tracheoles, finally end as blind, fluid filled fine branches which are attached with cells of tissue.Both the trachea and tracheoles are lined internally by thin layer of cuticle.MECHANISM OF RESPIRATION “INFLOW OF OXYGEN”The cockroach takes in air directly from the atmosphere into the trachea through spiracles. This air diffuses directly into fluid filled tracheoles through which diffuses into the cells of tissues. Hence the blood vascular system of

cockroach is devoid of haemoglobin.OUTFLOW OF CARBONDIOXIDERemoval of CO2 from cells of body is largely depended upon plasma of blood, which takes up CO2 for its ultimate removal through body surface via the cuticle.RESPIRATORY SYSTEM OF FISHMAIN RESPIRATORY ORGANIn fish, main respiratory organs are “Gills”. They are out growth of pharynx and lie internally with in the body so that they are protected from mechanical injuries.INTERNAL STRUCTURE OF GILLSEach gill is highly vascularized structure. It is composed of1. Filaments2. Gill bar or Gill arch3. Lamella1. FILAMENTSEach gill is composed of two rows of hundreds of filaments, which are arranged in V-shape.2. GILL BAR OR GILL ARCHFilaments are supported by a cartilage or a long curved bone the gill bar or gill arch.3. LAMELLALamella is a plate like structure which is formed by infolding of filaments. Lamella greatly increase the surface area of the gill. Each lamella is provided by a dense network of capillaries.OPERCULUM (IN BONY FISHES)Gills are covered on each side by gill cover called “operculum”MECHANISM OF VENTILATIONIn bony fishes, ventilation is brought about by combined effect of mouth and operculum. Water is drawn into the mouth. It passes over the gills through pharynx and ultimately exists at the back of operculum through open operculur valve. Water is moved over the gills in a continuous unidirectional flow by maintaining a lower pressure in operculur cavity than in buccopharynx cavity.COUNTER CURRENT FLOW OF WATER AND BLOODGaseous exchange is facilitated in gills due to counter current flow of H2O and blood.In the capillaries of each lamella, blood flows in direction opposite to the movement of water across the gill. Thus the most highly oxygenated blood is brought to water that is just entering the gills and has even high O2 content than the blood. As the H2O flows over the gills, gradually loosing its oxygen to the blood, it encounter the blood that is also increasingly low in oxygen. In this way a gradient is establishment which encourages the oxygen to move from water to bloodIMPORTANCECounter current flow is very effective as it enables the fish to extract upto 80–90% of the oxygen from water that flows over the gills.

RESPIRATORY SYSTEM OF MANMAIN FUNCTION OF RESPIRATIONThe main function of respiratory system is inflow of O2 from the atmosphere to the body and removal of CO2 from body to the atmosphere.COMPONENTS OF RESPIRATORY SYSTEM(1) PAIRED LUNGSThe respiratory (gas exchange) organs.(2) AIR PASSAGE WAYSWhich conduct the air(3) THORACIC CAVITYWhich lodges the lungs(4) INTERCOSTAL MUSCLES AND DIAPHRAGMWhich decreases and increase the diameters of thoracic cavity(5) RESPIRATORY CONTROL CENTRESAreas in brain which control the respiration.DETAILS OF COMPONENTS+ THORACIC CAVITYPaired lungs with in the pleural sacs are situated in the thoracic cavity. Separating the thoracic cavity from the abdominal cavity is a dome-shaped musculo-tendinuous partition called as Diaphragm.BOUNDARIES OF CAVITYThoracic cavity is supported by bony cage (thoracic cage) which is made up of Sternum -> in front Vertebral column -> at the back 12 pairs of ribs -> on each side Ribs are supported by Intercostal musclesFUNCTIONIncrease in thoracic cavity diameter is responsible for inspiration. While decrease in diameter is responsible for expiration.AIR PASSAGE WAYSAir is drawn into the lungs by inter-connected system of branching ducts called as “Respiratory tract” or “Respiratory passage ways”Air passage ways consists ofAIR CONDUCTING ZONE(which only conducts the air)1. Nostrils2. Nasal Cavity3. Pharynx (nasopharynx and oropharynx)4. Larynx5. Trachea6. Bronchi7. Bronchioles (also called terminal Branchioles)RESPIRATORY ZONE(Where gaseous exchange takes place)8. Respiratory Bronchioles9. Alveolar duct10. Alveolar sacs or alveoliGENERAL FUNCTIONS OF CONDUCTING AIR PASSAGES1. Conduction of air from atmosphere to the lungs

2. Humidification of inhaled dry air.3. Warming / cooling of air to body temp.4. The injurious particles are entrapped by mucous and removed by ciliary movements.5. Lymphoid tissues of pharynx provide immunological functions6. Cartilages prevent the passages from collapse but are not present in Bronchioles which remains expanded by same pressure that expand the alveoli.CONDUCTING ZONE1. NASAL CAVITYAtmospheric air enters the respiratory tract through a pair of openings called external nares (Nostrils), which lead separately into nasal cavity. Nasal cavity opens into naso pharynx through posterior nares (choanae).Nasal cavity is lined internally by Pseudostratified columnar ciliated epithelium containing mucous secreting cells.Hairs, sweat and sebaceous glands are also present.SPECIALIZED FUNCTIONS Warming of air Humidification or moistening of air Filteration of air with the help of hairs All these together called as Air conditioning function of upper respiratory passages Olfaction ( sense of smell)2. PHARYNXAir enters from Nasal cavity into pharynx through internal nostrils. The openings of nostrils are guarded by soft palate. It is internally lined by Pseudostratified ciliated epithelium, mucous glands are also present.FUNCTIONPharynx is responsible for conduction of air as well as food3. LARYNX (VOICE BOX)Pharynx leads air into larynx through an opening called glottis. Glottis is guarded by flap of tissue called epiglottis. During swallowing, soft palate and epiglottis close the nostrils opening and glottis respectively so that food is prevented to go either into nasal cavity or glottis. Larynx, a small chamber consists of pair of vocal cordsFUNCTIONDuring speech, vocal cords move medially and their vibration produce sound4. TRACHEA (WIND PIPE)Larynx leads the air into a flexible air duct or trachea. It bears C-shaped tracheal cartilages which keep its lumen patent during inspiration. Its internal lining is pseudostratified columnar ciliated epithelium containing mucous secreting goblet cells.FUNCTIONConduction of airDue to mucous and upward beating of cilia, any residues of dust and germs are pushed outside the trachea towards the pharynx.5. BRONCHI“At its lower end, trachea bifurcates into two smaller branches called Principle

Bronchi↑ which leads the air into lung of its side. They are also supported by C-shaped cartilage rings upto the point where they enter the lungs”.In all areas of trachea and bronchi, not occupied by cartilage plates, the walls are composed mainly of smooth muscles.6. BRONCHIOLESOn entering the lungs, each bronchus divide repeatidly. As the bronchi become smaller, U-shaped bars of cartilage are replaced by irregular plates of cartilages. The smallest bronchi divide and give rise to Bronchioles (less than 1.5 mm in diameter).7. TERMINAL BRONCHIOLESBronchioles divide and give rise to terminal bronchioles (less than 1 mm in diameter). Walls possess no cartilages and are almost entirely the smooth muscles. These are the smalled airways without alveoli.RESPIRATORY ZONEIn this zone of respiratory tract, gaseous exchange between capillary blood and air takes place.1. RESPIRATORY BRONCHIOLESTerminal bronchioles show delicate outpouchings from their walls, which explains the name Respiratory Bronchioles (less than 0.5 mm in diameter). They bear the pulmonary alveoli.2. ALVEOLAR DUCTS AND SACSEach respiratory bronchioles terminates at a tiny hollow sac like alveolar duct that lead into tabular passages with numerous thin walled out pouchings called Alveolar sacs.3. PULMONARY ALVEOLIThe alveolar sacs consists of several alveoli openings into a single chamber. Alveoli are the site of exchange of respiratory gases so they are considered as Respiratory surfaces of lungs. Each alveolus is surrounded by a network of blood capillaries.INTERNAL STRUCTURE OF ALVEOLIThe alveolar lining cells consists of1. Type I cells2. Type II cellsThey are also called pneumocytes.“Bifurcation of trachea is called Carina”.TYPE I PNEUMOCYTESSquamous shaped cells which form the epithelial lining of alveoliTYPE II PNEUMOCYTESIrregular and cuboidal shaped cells which secretes a substance called SurfactantSURFACTANTThe internal area of an alveoli is provided with a thin layer of fluid called as Surfactant secreted by type II cells.FUNCTION OF SURFACTANT1. It reduces the internal surface tension of alveoli which prevent it collapsing during expiration.2. It increases the compliance.3. It stabilize the alveoli.

4. It also helps to keep the alveoli dry.LUNGSLungs are paired, soft, spongy, elastic and highly vascularized structures, which occupy most of thoracic cavity. In child they are pink, but with age they become dark and mottled due to inhalation of dust.RIGHT LUNGPartitioned into 3 lobes by two fissures.LEFT LUNGDivided into 2 lobes by one fissures.PLEURAL MEMBRANESEach lung is enclosed by two thin membranes called as Visceral and parietal pleural membranes.PLEURAL CAVITYIn between the membranes there is a narrow cavity, the pleural cavity filled with pleural fluid which acts as lubricant.FUNCTION OF CAVITY1. Cardinal function is to exchange gases.2. Phagocytosis of air borne particles3. Temperature regulation4. Removal of water5. Maintainence of acid-base balance (by elemination of CO2)6. Acts as Reservoir of blood.BREATHINGDEFINITION“Breathing is the process of taking in (inspiration or inhalation) and giving out of air (expiration or exhalation) from the atmosphere up to the respiratory surface and vice versa”TYPES OF BREATHINGThere are two types of BreathingNegative pressure BreathingPositive pressure BreathingNEGATIVE PRESSURE BREATHINGNormal breathing in man is termed as negative pressure breathing in which air is drawn into the lungs due to negative pressure (decrease in pressure in thoracic cavity in relation to atmospheric pressure).POSITIVE PRESSURE BREATHING“In this kind of breathing, lungs are actively inflated during inspiration under positive pressure from cycling valve”.EXAMPLESFrog uses positive pressure breathing.PHASES OF BREATHING1. INSPIRATION OR INHALATION2. EXPIRATION OR EXHALATION(1) INSPIRATIONDEFINITION“Inspiration is an energy consuming process in which air is drawn into the lungs due to negative pressure in thoracic cavity”MECHANISM

During inspiration volume of thoracic cavity increases which creates a pressure (intra thoracic) that sucks the air into the lungs.INCREASE IN VOLUME OF THORACIC CAVITYVolume of thoracic cavity increases due to1. Inc. in Anterio-posterior diameter2. Inc. in Vertical diamter.INCREASE IN ANTERIO-POSTERIOR DIAMETER During contraction of external intercostals muscle, the ribs as well as the sternum move upward and outward, which causes the increase in anterior-posterior diameter of thoracic cavity.INCREASE IN VERTICAL DIAMETERVertical diameter of thoracic cavity inc. due to Contraction (descent) of Diaphragm which makes it flat.As a consequence thoracic cavity enlarges and the pressure is developed inside the thoracic cavity and ultimately in the lungs. So the air through the respiratory tract rushes into the lungs upto the alveoli where gaseous exchange occurs.(2)EXPIRATIONDEFINITION“It is reserve of inspiration. The passive process in which air is given out of lung due to increased pressure in thoracic cavity is called “Expiration”MECHANISMDuring expiration, elastic recoil of pulmonary alveoli and of the thoracic wall expels the air from the lungs.DECREASE IN VOLUME OF THORACIC CAVITYVolume of thoracic cavity ↓ due to1. DECREASE IN ANTERIO-POSTERIOR DIAMETER2. DECREASE IN VERTICAL DIAMETER(1) DECREASE IN ANTERIO-POSTERIOR DIAMETERIt is caused by relaxation of external intercostals muscles and contraction of internal intercostals muscles which moves the ribs and sternum inward and downward.(2) DECREASE IN VERTICAL DIAMETERIt is caused by relaxation of diapharagm which makes it dome shaped thus reducing the volume of thoracic cavity.As a consequence, the lungs are compressed so the air along with water vapours is exhaled outside through respiratory passage.CONTROL OF RATE OF BREATHINGRate of breathing can be controlled by two modes.VOLUNTARY CONTROLINVOLUTARY CONTROLVOLUNTARY CONTROLBreathing is also under voluntary control by CEREBRAL CORTEXEXAMPLESWe can hold our breath for short time or can breath faster and deeper at our will.INVOLUNTARY CONTROLMostly, rate of breathing is controlled automatically. This is termed as

Involuntary control which is maintained by coordination of respiratory and cardio-vascular system.TWO MODES OF INVOLUNTARY CONTROLA. NERVOUS CONTROL (through respiratory centers in brain)B CHEMICAL CONTROL (through chemoreceptors)(A) NERVOUS CONTROL Control of rate of breathing by nervous control is through the Respiratory centers in Medulla oblongata which are sensory to the changes in Conc. of CO2 and H+ present in the cerebro-spiral fluid (CSF).RESPIRATORY CENTRES IN MEDULLATwo center are present

(1) DORSAL GROUP OF NEURONSMedulla contains a dorsal group (Inspiratory group) of neurons responsible for inspirationFUNCTIONIn response to increase conc. of CO2 and H+ (decreased pH), it sends impulses to the intercostals muscles to increase the breathing rate(2) VENTRAL GROUP OF NEURONSAnother area in the medulla is ventral (expiratory) group of neurons.FUNCTIONIt inhibits the dorsal group and mainly responsible for expiration(B) CHEMICAL CONTROLChemical control of rate of breathing is through chemoreceptors.LOCATION OF CHEMORECEPTORSAORTIC BODIESCAROTID BODIESAORTIC BODIESThe peripheral chemoreceptors which are located above and below the arch of aorta are called Aortic bodies. It sends impulses to medulla through Vagus nerve.CAROTID BODIESChemoreceptors which are located at the bifurcation of carotid arteries are called Carotid bodies. It sends impulses to medulla through Glossopharyngeal nerve.FUNCTIONInc. in concentration of CO2 and H+ in blood are basic stimuli to increase the rate of breathing which are monitered by these chemoreceptors and then send the impulses to medulla oblongata which produce action potential in inspiratory muscles.DISORDERS OF RESPIRATORY TRACT(1) LUNG CANCER (BRONCHIAL CARCINOMA)CAUSES Smoking is a major risk factor either acitively or passively. Asbestos, nickel, radioactive gases are associated with increased risk of bronchial cascinoma

PHYSIOLOGICAL EFFECTS+ LOSS OF CILIAThe toxic contents of smoke such as nicotine and SO2 cause the gradual loss of cilia of epithelical cells so that dust and germ are settled inside the lungs.+ ABNORMAL GROWTH OF MUCOUS GLANDSTumor arises by uncontrolled and abnormal growth of bronchial epithelium mucous glands. The growth enlarges and some times obstruct a large bronchus.The tumours cells can spread to other structures causing cancer.SYMPTOMS Cough- due to irritation Breath lessness – due to obstruction.(2)TUBERCLOSIS (KOCH’S DISEASE)(INFECTIOUS DISEASE OF LUNG)CAUSECaused by a Bacterium called as “MYCOBECTERIUM TUBERCLOSIS”PHYSIOLOGICAL EFFECTS Tuber Bacili causes Invasion of infected region by macrophages Fibrosis of lungs thus reducing the total amount of functional lung tissuesThese effects cause Increased work during breathing Reduced vital and breathing capacity Difficulty in diffusion of air from alveolar air into blood.SYMPTOMS Coughing (some time blood in sputum) Chest pair Shortness of breath Fever Sweating at night Weight loss Poor apetitePREVENTIONA live vaccine (BCG) provides protection against tuberclosis.3.COPD-(CHRONIC OBSTRUCTIVE PULMONARY DISEASE)They includeA. EmphysemaB. Asthma(3-A)EMPHYSEMACAUSESIt is a chronic infection caused by inhaling Smoke and other toxic substances such as Nitrogen dioxide and Sulphur dioxidePHYSIOLOGICAL EFFECTS

Long infection – Irritants deranges the normal protective mechanisms such as loss of cilia, excess mucus secretion causing obstruction of air ways Elasticity of lung is lost Residual volume increases while vital capacity decreases. Difficulty in expiration due to obstruction Entrapment of air in alveoli All these together cause the marked destruction of as much as 50-80% of alveolar walls. Loss of alveolar walls reduces the ability of lung to oxygenate the blood and remove the CO2 Oxygen supply to body tissues especially brain decreases.SYMPTOMS Victim’s breathing becomes labored day by day. Patient becomes depressed, irritable and sluggish. Concentration of CO2 increases which may cause death.(3-B) ASTHAMA“Respiratory tract disorder in which there are recurrent attacks of breathlessness, characteristically accompanied by wheezing when breathing out.”CAUSESIt is usually caused by Allergic hypersensitivity to the plant pollens, dust, animal fur or smoke or in older person may be due to common cough.Heridity is major factor in development of Asthma.PHYSIOLOGICAL EFFECTS Localized edema in walls of small bronchioles. Secretion of thick mucus. Spastic Contraction of bronchial smooth muscles (so the resistance in air flow increases). Residual volume of lung increases due to difficulty in expiration. Thoracic cavity becomes permanently enlarged.SYMPTOMS The asthmatic patient usually can inspire quite adequately but has great difficulty in expiring.LUNG CAPACITIES1. TOTAL AVERAGE LUNG CAPACITYDEFINITION

“It is the maximum volume in which the lung can be expanded with greatest possible inspiratory efforts.”

Or“Total lung capacity is the combination of residual volume and vital capacity.VALUETotal lung capacity = 5000 cm3 or 5 lit of air.

2. TIDAL VOLUME“The amount of air which a person takes in and gives out during normal breathing is called Tidal Volume.”VALUE450cm3 to 500 cm3 (1/2 litre)3. INSPIRATORY RESERVE VOLUMEDEFINITION‘“Amount of air inspired with a maximum inspiratory effort in excess of tidal volume.”VALUE200 cm3 or 2 lit. (Average value)4. EXPIRATORY RESERVE VOLUMEDEFINITION“Amount of air expelled by an active expiratory effort after passive expirations.”VALUE1000 cm3 or 1 litre.5. VITAL CAPACITYDEFINITION

“After an extra deep breath, the maximum volume of air inspired and expired is called Vital capacity.”Or“It is the combination of inspiratory reserve volume, expiratory reserve volume and tidal volume.”VALUEAverages about 4 litre.6. RESIDUAL VOLUMEDEFINITION

“Amount of air which remains in lung after maximum expiratory effort is called Residual volume.”VALUEApproximately 1 litre or 1000 cm3.IMPORTANCE OF LUNG CAPACITY Residual volume prevent the lung from collapsing completely. Responsible for gaseous exchange in between breathing. It is not stagnant since inspired air mixes with it each time. Aging or Emphysema, etc can increase the residual volume at the expense of vital capacity.HAEMOGLOBININTRODUCTION“Haemoglobin is an iron containing respiratory pigment present in the red blood cells of vertebrates and responsible for their red colour.”STRUCTUREHaemoglobin consists of1. Heme

2. Protein (globin like chains)1. HEMEOne Haemoglobin molecule consists of 4 molecules of Heme. Each Heme molecule contains an iron (Fe++) binding pocket. Thus one molecule of Haemoglobin can combine with 4 iron atoms.2. GLOBINEach Hb molecule contains four globin like chains (Two α chains and Two β chains).ROLE OF HB DURING RESPIRATIONTwo major functions are performed by Hb.1. Transport of O2 from lung to tissues.2. Transport of CO2 from tissues to lungs.1. “TRANSPORT OF O2 FROM LUNGS TO TISSUES”“Nearly 97% of O2 is transported from the lungs to the tissues in combination with Hb.”ATTACHMENT OF O2 WITH HBIt is the iron of Hb molecule which reversibly binds with oxygen. One Hb molecule can bind 4 molecules of O2. Thus due to Hb, blood could carry 70 times more oxygen than plasma.MECHANISM OF TRANSPORT Due to high O2 concentration in alveolar air, the O2 moves from air to the venous blood where O2 concentration is low. It combines loosely with Hb to form Oxyhemo Globin. In this form, O2 is carried to the tissues where due to low oxygen concentration in tissues, oxy Hb dissociates releasing oxygen, which enters in tissues.Whole process can be represented by following equation.2. “TRANSPORT OF CO2 FROM TISSUES TO LUNGS”“Haemoglobin is also involved in 35% of transport of CO2 from tissues to alveolar blood capillaries in alveoli.”ATTACHMENT OF CO2 WITH HBCO2 binds reversibly with NH2 group of Hb to form loose compound called “Carboamino Haemoglobin.”MECHANISM OF TRANSPORT Carbon dioxide due to its higher concentration in tissue diffuses out into the blood where it combines with Hb to form Carboamino Hb. In the alveoli it breaks and CO2 diffuses out into the Alveoli from where it is expired.MYOGLOBININTRODUCTION“Myoglobin is a heme protein, smaller than Hb, found in muscles and giving red colour to them.STRUCTUREMyoglobin consists of one heme molecule and one globin chain. It can combine with one iron (Fe++) atom and can carry one molecule of O2.FUNCTION OF MYOGLOBIN

Myoglobin has high affinity for O2 as compared to Haemoglobin so it binds more tightly. It stores the O2 within the muscles. It supplies the O2 to the muscles when there is severe oxygen deficiency (During exercise)It can be represented as follows:Mb + O2 ↔ MbO2TRANSPORT OF GASESOxygen and carbondioxide are exchanged in, Alveoli by Diffusion.O2 TRANSPORTBlood returning into the lungs from all parts of body is depleted from oxygen. This deoxygenated blood is dark maroon in colour to appear bluish through skin. It becomes oxygenated in the lungs.TWO FORMS OF O2 IN BLOODO2 is transported in the blood in two forms: Dissolved form (3%) Combination with Hb (97%) ® OxyhaemoglobinMECHANISM OF O2 TRANSPORT+ DIFFUSION OF O2 FROM ALVEOLUS INTO PULMONARY BLOODThe air inhaled into the lungs has high concentration of oxygen while venous blood in pulmonary capillaries has low in concentration. Due to this difference in concentration across the respiratory surface, oxygen diffuses into the blood flowing into capillaries around the Alveoli. Now blood becomes oxygenated which is bright red in colour.+ DIFFUSION OF O2 FROM CAPILLARIES INTO CELLSConcentration of O2 in the arterial end of capillaries is much more greater than concentration of O2 in the cells. So O2 diffuses from the blood to the body cells. Since the blood takes in oxygen much more rapidly than water. Thus it can transport enough oxygen to the tissues to meet their demand.CO2 TRANSPORTBlood returning from tissues contain excess of CO2 as a respiratory by-product, which is eliminated from the body during expiration in the lungs.”THREE FORMS OF CO2 IN BLOOD Dissolved form (in plasma) – 5% In form of HCO3- (in RBC’s) – 60% In combination with Hb (Carboamino Hb) – 35%+ DISSOLVED FORMOnly 5% of CO2 is transported in dissolved form in plasma. Here it combines with H2O of plasma to form H2CO3. But this reaction is very slow as plasma does not contain Carbonic Anhydrase to accelerate this reaction.Reactions can be represented by following equations.CO2 + H2O ↔ H2CO3H2CO3 ↔HCO3- + H+HCO3- + k+ ↔ KHCO3+ IN FORM OF HCO3-60% of CO2 is transported in the blood in form of HCO3- in RBC’s. Here it

combines with water to form H2CO3. But this reaction occurs rapidly in RBC’s due to presence of Carbonic Anhydrase.Reactions can be represented by following equationsCO2 + H2O ↔ H2CO3H2CO3 ↔ HCO3- + H+HCO3- + Na+ ↔ NaHCO3+ IN COMBINATION WITH HBAs discussed previously in role of Hb.MECHANISM OF CO2 TRANSPORT+ DIFFUSION OF CO2 FROM CELLS INTO CAPILLARIESCO2 is continuously synthesizing in the tissues as a result of metabolism. Thus due to its higher concentration. CO2 diffuses from the tissues into blood, which becomes deoxygenated.+ DIFFUSION OF CO2 FROM PULMONARY BLOOD INTO ALVEOLUSBlood returning from tissues contain high concentration of CO2. This blood is brought to lungs, where CO2 diffuses from the blood into alveolus where its concentration is lower.FACTORS EFFECTING THE TRANSPORT OF GASESFollowing are some factors, which influence the transport of respiratory gases across the alveolar wall.1. Concentration Gradient2. Presence of competitor such as CO3. Moisture4. Surfactant5. pH

BotonyDIFFUSION The movement of ions or molecules from the region of higher concentration to the region of lower concentration is known as diffusion.EXAMPLES1. If a bottle of perfume is opened in a corner of a room, it can be smelt in the entire room.2. Leakage of gas pipes can be smelt from a farther point.3. If we drop a KMNO4 crystal in clean water, then after sometime the crystals

will dissolve and colour of water changes from colorless to purple.FACTORS ON WHICH RATE OF DIFFUSION DEPENDS1-SIZESmall molecules move faster than larger ones.2-TEMPERATURERate of diffusion will be high at high temperatures.3-CONCENTRATION GRADIENTGreater the difference in concentration and shorter the distance between two regions, greater will be the rate of diffusion.FACILITATED DIFFUSIONDiffusion of the substances across the cell membrane through the specific carrier proteins is known as facilitated diffusion. These membrane transport proteins are channel proteins, receptors, cell pumps or carriers, made up of usually proteins and don’t require energy for transport.PASSIVE TRANSPORTMovement of substances in and out of the cell, caused by simple kinetic motion of molecules, doesn’t require energy of ATP is known as passive transport, e.g. Simple diffusion and facilitated diffusion.OSMOSISThe movement of water molecules from the region of higher concentration to the region of lower concentration through a semi-permeable membrane, is known as osmosis.TYPES OF OSMOSISA- ENDOSMOSISThe movement of water molecules into the cell, when it is placed in hypotonic solution is called as Endosmosis.B- EXOMOSISThe movement of water molecules out of the cell when the cell is placed in a hypertonic solution.ACTIVE TRANSPORTThe movement of ions or molecules across the cell membrane against the concentration gradient i.e. from lower concentration to higher concentration with the help of specific transport proteins in the cell membrane, at the expense of cell’s metabolic energy – ATP is called active transport.EXAMPLES1. Sodium-Potassium pump in nerve cells which pump Na+ out of the nerve cell, and K+ into the cell against the concentration gradient.2. Cells lining the intestine can transport glucose actively from a lower concentration in the intestinal contents to higher concentration in blood.3. In plants phloem loading is an ex. Of active transport.IMBIBITIONSAdsorption of water and swelling up of hydrophilic (water loving) substances is known as imbibitions.HYDROPHILIC SUBSTANCES

Those which have great affinity for water are hydrophilic e.g. starch, gum, protoplasm, cellulose, proteins, e.g. seeds swell up when placed in water.

Wrapping up of wooden framework during rainy seasons. Dead plant cells are hydrophilic colloids. The chemical potential of water is a quantitative expression of the free energy associated with the water. UNIT: Joules/mole This term has been replaced by water potentialWATER POTENTIAL (PSI)It is the difference between the fee energy of water molecules in pure water and energy of water in any other system, or solution. Water potential is a relative quantity, depends upon gravity and pressure.Q = Q* + f (concentration) + f (pressure) + f (gravity)Β* is standard water potential or pure water potential of valve O Mpa.Unit : Megapascal’s – MPa(1 Mpa = 9.87 atmospheres)USESThe direction of water flow across cell membrane can be determined. It is a measure of water status of the plant.OSMOTIC PRESSUREThe pressure exerted upon a solution to keep it in equilibrium with pure water when the two are separated by a semi permeable membrane is known as Osmotic pressure.It prevents the process of osmosis.OSMOTIC POTENTIALThe tendency of a soln to diffuse into another, when two solutions of different concentrations are separated by a differentially permeable membrane. It is represented by βs for pure water βs = 0 The βs decrenses as the osmotic concentration increases. Osmotic concentration is the number of osmotic-ally active particle per unit volume. Osmotic potential has been replaced by solute potential. The concentration of solute particles in a solution is know as solute potential βs. It value is always negative.PRESSURE POTENTIAL ΒPWhen a cell is placed in pure water or in aqueous solution with higher water potential than the cell sap water follows into the vacuole by endosmosis thru cell membrane and tonoplast. Due to this inflow of water, the tension developed by the cell wall causes an internal hydrostatic pressure to develop, which is called as pressure potential.Β = βs + βp or Qp = Q – QsIn turgid cells βp is equal and opposite to βsTURGID CELL

When the cell is fully stretched with maximum pressure potential, the water cannot flow into it. This condition is called turgidity and the cell is turgid.PLASMOLYSISIf a cell is placed in a hypertonic solution, which has more negative solute and water potentials then water will come out of the cell, by exosmosis and protoplasm starts separating from cell wall leaving a gap between cell wall and cell membrane. This withdrawal of protoplasm from cell wall is known as plasmolysis.The point where protoplasm just starts separating from cell wall is known as “Incipient plasmolysis” when it is completely separated, full plasmolysis occurs.In plasmolysis cell βp = 0 therefore βw = βsDEPLASMOLYSISWhen a cell is placed is a hypotonic solution or pure water, there will be an inflow of water by endosmosis. Protoplasm starts expanding and presses cell wall due to which pressure potential develops and water potential becomes less negative. This swelling of cell is known as deplasmolysis.WATER AND MINERALS UPTAKE BY ROOTS1. Absorption of water and mineral salts takes place through root system.2. Roots are provided with enormous number of tiny root hairs.3. These root hairs are more in number in tap root system.4. Roots hairs are out growths of epidermal cells.5. Roots hairs increase the surface area for absorption.6. Most of the absorption takes place at root tips.7. From hairs and epidermal cells water flows thru cortex, endodermis, pericycle and them enters xylem.There are 3 pathways for water to enter xylem.A- CELLULAR PATHWAYIn this route water flows through cell to cell. Water enters the root hairs or epidermal cells down a concentration gradient: it flows through cell wall and cell membrane and enters the adjacent cell from where water may again flow towards the deeper cells by osmosis.B- SYMPLAST PATHWAYCytoplasm of the cortical cells are interconnected by small pores in the cell wall known as plasmodesmata.These pores provide another way of transporting water and solutes across the plasma membrane at root hairs.C- APOPLAST PATHWAYThe cell walls of cortical and epidermal cells are hydrophilic and form a continuous matrix. Soil solution flows freely through these hydrophilic walls. The movement of soil soln.through extra cellular pathway provided by continuous matrix of cell walls is known as “Apoplast pathway”.Simplast and apoplast usually both occur concurrently.Endodermis forms a waxy barriers against the flow of water and salts known as “casparion strip”. So, water cannot enter endodermis via apoplast pathway.

Symplast is the only way to cross the barrier. Endodermal cells actively transport salts to pericycle resulting in high osmotic potential which causes inflow of water by osmosis salts. Form pericycle water flows in to xylem via both symplast and apoplast pathways.TRANSPIRATIONThe loss of water in the form of vapours from aerial parts of the plant is called transpiration.TYPES OF TRANSPIRATIONFollowing are the three types of transpiration.A- STOMATAL TRANSPIRATIONIt is a type of transpiration in which the water vapours escape through the stomata. 90% of the total transpiration occur thru this method. In isobilateral leaves the stomata are present in both upper and lower epidermis e.g. lily and maize leaves. In dorsiventral leaves, the stomata are only confined to lower epidermis e.g. Brassica and sunflower.B- CUTICULAR TRANSPIRATIONThe loss of water in the form of vapours through the cuticle of leaves is called Cuticular Transpiration. About 5-7% of total transpiration takes place thru this route cuticle is a waxy layer which covers the leaves and tis is not completely impermeable to water.C- LENTICULAR TRANSPIRATIONIt is the loss of water vapours through lenticles present in the stems of dicot plants. Lecticles are aerating pores present in the bark formed as a result of secondary growth. It accounts for only 1-2% of total transpiration.MECHANISM OF STOMATAL RESPIRATIONSTRUCTURE OF STOMATAStomata are microscopic pores present in the epidermis of leaves and herbaceous stems. Number of stomata are variable in different leaves and depend upon the availability of water and climate of the region. Each stomata is surrounded by 2 specialized epidermal cells, as guard cells, they are bean shaped or kidney shaped and unlike other epidermal cells, they contain chlorophyll, hence perform photo-synthesis. The inner wall of guard cell is thick while the outer wall is thin and elastic. This structural difference is important for opening and closing of stomata.STAGES OF TRANSPIRATIONThere are two processes involved in stomata transpiration.+ EVAPORATIONIn the first step, water evaporates from the wet surfaces of turgid mesophyll cells and collected in the intercellular air spaces.+ DIFFUSIONIn this stage water vapours diffuse out from intercellular spaces where they are in higher concentration to the outer atmosphere where they are in lower concentration through the stomata.MECHANISM OF OPENING AND CLOSING OF STOMATA

The opening and closing of stomata depends upon the turgidity of guard cells, which is due to increase or decrease in the osmotic potential of the guard cells. When water enters the guard cells by osmosis, they swell up. Since their outer walls are thin and elastic, they stretch and bulge out. The inner thick walls cannot stretch and so arch in and become crescent shaped thus the gap between the two guard cells widens, opening the stomata when the guard cell lose water, they become flaccid and the inner wall of two guard cells meet each other, closing the stomata.Generally the stomata remain open during day time and close at night. Thus light appears as the primary factor which control the opening and closing of stomata.FACTORS REGULATING OPENING AND CLOSING OF STOMATAThere are two main factors which greatly influence the opening and closing of stomata these are1- LIGHTIn the presence of light, chlorophyll containing guard cells synthesize sugars which is turn increase the osmotic potential of guard cells. This increase Qs results in endosmosis and ultimately to turgidity. While in darkness these guard cells consume carbohydrates (sugars) by respiration for energy production or transported to other neighbouring cells for respiration and different purposes. This decreases the osmotic potential of guard cells leading to flaccidity because of exomosis of water.2- CONCENTRATION OF K+ IONSTurgidity of guard cells of many plants is regulated by K+ ion concentration. During daytime, guard cells actively transport K+ions into them from neighbouring cells. Accumulation of K+ ions lowers the water potential of guard cells. This causes on inflow of water by endosmosis from epidermal cells. During night when they lose K+ ion, water potential increases. Water flows out of the guard cells by exosmosis causing them to become flaccid which result in closure of pore.FACTORS AFFECTING TRANSPIRATIONRate of transpiration is very important for a plant because transpiration stream is necessary to distribute dissolved mineral salts through out the plants. Water is transported to photosynthesizing cells of leaves. Transpiration is also very important as it cools the plant. This is especially important in higher temperatures. If the rate of transpiration is very high, there would be much loss of water from the plant. So at high temperatures the stomata almost close and reduction in the rate of transpiration is effected. This stops witting of the leaves and of herbaceous stems of plants.Following are some important factors which affect the rate of transpiration.1. LIGHTLight affects the transpiration in two ways:a. Light regulates the opening and closing of stomata. During sunshine the stomata are open, losing water vapours thus rate of transpiration is high and

during night, the stomata are closed, so the rate of transpiration is low.b. Greater intensity of light, increases the temperature and warms the leaf, so leaves lose heat by evaporating water molecules to cool themselves.2. TEMPERATUREPlants transpire more rapidly at higher temperature than at low. Rise in temperature has two effects:i. It increases kinetic energy of water molecules, which results in rapid evaporation of water and decreases the rate of transpiration.ii. High temperature reduces the humidity of surrounding air. Due to this, evaporation from surfaces of mesophyll cells increase and hence rate of transpiration.3. WINDThe air in motion is called wind. The area around the stomata is saturated with water vapours due to transpiration. During high velocity wind the area around leaves is quickly replaced by fresh drier air which increases diffusion of water molecules from air spaces to outside atmosphere and increases the rate of transpiration.When air is still, the rate of diffusion of water molecules is reduced and the rate of transpiration is also reduced.4. HUMIDITYWhen air is dry, the rate of diffusion of water molecules, from the surfaces of mesophyll cells, air spaces and through stomata, to outside the leaf increases. So more water is lost, increasing the rate of transpiration.In humid air, the diffusion of water molecules is reduced. This decreases the rate of transpiration.5. SOIL WATERA plant can’t continue to transpire rapidly if its moisture loss is not made up by absorption of fresh supplies of water from the soil. When absorption of water by roots fails to keep up with rate of transpiration, loss of turgor occurs and wilting of leaf takes place.DISADVANTAGES OF TRANSPIRATION1. Transpiration is said to be necessary evil because it is an inevitable, but potentially harmful, consequence of the existence of wet cell surfaces from which evaporation occurs.2. High rate of transpiration causes water deficiency and thus the excessive transpiration leads to wilting and death of plants.3. There is good evidence that even mild water deficiency results in reduced growth rate of plants.4. Excessive transpiration effects the protein synthesis, sugar synthesis and other metabolic activities of plants.ADVANTAGES OF TRANSPIRATION1. Water is conducted in most parts of plants due to transpiration pull or ascent of sap.2. It causes absorption of water and minerals from the soil.

3. Minerals dissolved in water are conducted throughout the plant body by transpiration stream.4. Evaporation of water from the exposed surface of cells of leaves has cooling effect on plant.5. Excess water is removed.6. Wet surface of leaves allow gaseous exchange.GUTTATIONIt is the loss of water in the form of droplets from the ends of large leaf-veins. It take place through special openings called hydathodes.DIFFERENCES BETWEEN TRANSPIRATION AND GUTTATIONTRANSPIRATIONWater escapes in the form of wapours.Escape water is pure and does not contain solutes.It takes place through stomata, and cuticle.It is regulated by stomata.Normally takes place in lightGUTTATIONWater escapes as liquid.Escaped water contain solutes.It takes place through hydathodes and end of veins.It is not a regulated process.Takes place at night.TRANSLOCATION OF ORGANIC SOLUTESTransport of organic products of photosynthesis, like sugars from mature leaves to the growing and storage organs in plants is called translocation. This movement of photo assimilates and other organic materials takes place via the phloem and is therefore called “Phloem Translocation.”The phloem is generally found on the outer side of xylem and constitutes the bark. The cells of phloem that take part in phloem translocation are called sieve elements. Phloem tissue also contains companion cells, parenchyma cells, fibres like sclereids latex containing cells. But only sieve tube cells are directly involved in tansport of organic solutes.SOURCE TO SINK MOVEMENTThe translocation of photosynthesis always takes place from source to sink tissues, therefore, the phloem transport is also referred as “source to sink movement.”SOURCEThe part o plant which forms the sugars or photoynthates is known as source. For example Mature Leaves.SINKSinks are the areas of active metabolism or storage of food e.g: Roots, Tubers developing fruits, immature leaves, growing tips of roots and shoots. Some source and sinks are interconvertible during the process of development of plants. For example: developing and mature leaves, developing and

germinating seeds, root of sugar beets etc.MUNCH HYPOTHESIS (MECHANISM OF PHLOEM TRANSLOCATION)Phloem translocation is mainly explained by a theory called the “Pressure flow hypothesis” proposed by Ernest munch in 1930 which explains the steps involved in the movement of photosynthates from mesophyll chloroplasts to the sieve elements of phloem of mature leaves.STEPSThe following steps explain flow theory:1. The glucose formed during photosynthesis in mesophyll cells, is used in respiration or converted into non-reducing sugar i.e. sucrose.2. the sucrose is actively transported to bundle sheath cells and then to companion cell of the nearest smallest vein in the leaf. This is called “short distance transport” because solutes cover only a distance of two or three cells.3. Sucrose diffuse into sieve tube cell or sieve elements by symplast pathway or apoplast pathway. This is called phloem loading, this raises the conc. of sugars in sieve elements, which causes osmosis of water from nearby xylem in the leaf. It causes an increase in the hydrostatic pressure or tugor pressure.4. The increase hydrostatic pressure moves the sucrose and other substances in the sieve tube cells, and moves to sinks. The photo-assimilates (sugars etc) can be moved a long distance i.e. of several meters, therefore this is known as “Long distance transport.”5. In the sink tissues, present at the other end of pathway, sugars are delivered by phloem by an active process called “Phloem Unloading.” It produces a low osmotic pressure in sieve elements of sink, as a result of this water potential begins to rise in the phloem and causes an exosmosis of water molecules from the sieve tubes. This causes a decrease in turgor pressure of the sieve tubes (phloem).6. The presence of sieve plates in the sieve elements greatly increases the resistance along the pathway and results in the generation and maintenance of a substantial pressure gradient in the sieve elements between source and sink. The sieve elements contents are physically pushed along the traslocation pathway by bulk flow, much like water flowing through a garden house.SIGNIFICANCE OF TRANSLOCATION1. Food can be formed or stored as in sugar beet’s root or stem of sugar cane.2. Sucrose is transported to sink where it is converted to glucose and used as energy.3. Productivity of crop can be increased by accumulation of photo-synthates in edible sink tissues like cereal grains, pulses, ground nuts etc.4. Fruit is forme by this process e.g. Apples, Mango etc.ASCENT OF SAPThe upward movement of water and dissolved mineral salts from the roots to the leaves agains the downward pull of gravity is known as “Ascent of Sap.”PATH OF MOVEMENTThe distance traveled by water is small and easy in plans like herbs and shrubs

and longest in tall trees like pinus, red wood, eucalyptus etc. For transport different tissues of xylem is used for conduction of water in different plants. These are open ended cells called “Vessels” and porous cells called “tracheids” (Fig. From book).A. VESSELS1. These are thick walled tube like structures which extend through several feet of xylem tissue.2. They range in diameter from 20μm to 70μm.3. Their walls are lignified and perforated by pits. At the pit, cell wall is only made up of cellulose. Pits of adjacent cells match up with each other, so that their cavities are interconnected.4. Xylem vessels arise from cylindrical cells, which placed end to end. They die at maturity forming a continuous duct, providing a channel for long-distance transport of water.5. Rate of flow of water is 10 times faster than tracheids.OCCURANCEVESSELS are mostly found in Angiospermic plants.B. TRACHEIDS1. These are individual cells about 30μm in diameter. They are several mm long and tapered.2. Like vessels, they are also dead, made up of thick lignified walls.3. Their walls are perforated by small pits, which are of two types, simple and bordered.4. The Tracheids are connected by pits and forming a long channel for conduction of water.OCCURANCEIn Ferns and Conifers.MECHANISM OF ASCENT OF SAPWater and dissolved mineral salts present in xylem, flow in upward direction at the rate of 15m/hour. Xylem sap ascends because of two reasons:1. Push from below – Root Pressure Theory2. Pull from above – Dixon’s Theory1. ROOT PRESSURE THEORYAccording to Stephen Hales:“The force which is responsible for the upward movement of water molecules in xylem is by the pushing effect from below (i.e. roots) and is known as “Root Pressure.” Root Pressure is created by active secretion of sals and other solutes from the other cells into xylem sap.This lowers the water potential of xylem sap. Water enters by osmosis, thus increasing the level of sap. Water also take apoplast or symplast pathway to enter the xylem cells, this increased level causes a pressure effect in xylem and pushes the water upwards.OBJECTIONS/FAILURE OF THEORY1. This force is unable to push water in tall plants.

2. It is seasonal.3. Completely absent from Cycads and Conifers, so how they transfer water.4. When a cut shoot is placed in water, the water rises in shoots although roots are absent.5. It is also present in plant which donot have well developed root system.2. TRANSPIRATION PULL (DIXON’S THEORY) OR ADHESION-COHESION-TENSION THEORYDixon and Jolly proposed this theory for ascent of sap. It provides a reasonable explanation of flow of water and minerals from the roots to leaves of plants. It depends on:ADHESIONAdhesion is the sticking together of molecules of different kinds. Water molecules adhere to the cell walls of xylem cells, so that the column of water in xylem tissue doesn’t break. The cellulose of cell wall has great affinity for water, which helps in the process.COHESIONCohesion is the attraction among molecules of same kind, which holds water molecules together, forming a solid chain-like column within the xylem tubes. Extensive hydrogen bonding in water gives rise to property of cohesion. The molecules of water in xylem tube form a continuous column.TRANSPIRATION PULLThe loss of water from the aerial parts of the plant especially through stomata of leaves is called transpiration.During daytime the leaf after absorbing sunlight, raising its temperature starts transpiration. When a leaf transpires, the water potential of its mesophyll cells drop. This drop causes water to move by osmosis from the xylem cells of leaf into dehydrating mesophyll cells.The water molecules leaving the xylem are attached to other water molecules of tube by H-bonding.Therefore, when one water molecules moves up the xylem, the process continues all the way to the root, where water is pulled from the xylem cells, i.e. tracheids or vessels.Due to this pulling force or transpiration pull, water in xylem is placed under tension which is transmitted to root through vessels. Tension is due to H-bonding and strong cohesive forces between water molecules, and is strong enough to pull water upto 200 metres or even more.ASCENT OF SAP IS SOLAR POWEREDTo transport water over a long distance, plants do not use their metabolic energy or ATPs. It is done only by forces like adhesion, cohesion, evaporation and presence of sunlight. Thus ascent of sap is “Solar Powered.”SIGNIFICANCE OF ASCENT OF SAP Water can be transported to the different parts of the plant. Transpiration is regulated. Food is formed in presence of water.

Photosynthesis requires water. Salts and minerals are also absorbed along water by roots.

Circulatory SystemHUMAN HEART INTRODUCTIONHeart, the most powerful organ in the circulatory system is conical, hollow & muscular organ, situated in middle mediastinum.POSITION OF HEARTHeart lies in the thoracic cavity between the lungs slightly towards left, enclosed with in ribcage with the sternum in front & vertebral column behind.SIZE & WEIGHTThe heart measures about 3 ½ Inches & weighs about 300 gm in males & 250 gm in females.MAIN FUNCTION OF HEARTHeart works continuously like a muscular pump & pumps the blood to various parts of the body to meet their nutritive requirements.COVERING OF HEART PERICARDIUMHeart is surrounded by a double layered pericarcdium. The outer layer is called Fibrous pericardium & inner layer is called as serous pericardium.PERICARDIAL FLUIDFluid is secreted in b/w the two layers of pericardium which is known as pericardial fluid.FUNCTIONPericardial fluid acts as LUBRICANT & reduces friction b/w heart walls & surrounding tissues during beating of heart.STRUCTURE OF HEARTHuman heart consists of four chambers.CHAMBERS OF HEART1. RIGHT ATRIUMRight Atrium is the right upper chamber of heart & acts as thin walled low pressure pump.OPENINGS (INLETS) OF RIGHT ATRIUM1. Superior Vena Cava2. Anfenior Vena Cava3. Coronary SinusFUNCTIONIt receives venous blood from the whole body & pump it to the right ventricle through the right atrioventricular (tricuspid opening) valve.2. LEFT ATRIUM

Left atrium is upper triangular chamber which is present posteriorly. It also acts as low pressure pump.OPENINGS (INLETS) OF LEFT ATRIUMTwo pairs of pulmonary veins.FUNCTIONIt receives oxygenated blood from the lungs through 4 pulmonary veins and pumps it to the left ventricle through the left atrioventricular orifice (mitral or bicuspid).3. RIGHT VENTRICLERight ventricle is the right lower chamber of heart, which is triangular in shape.OPENINGS OF RIGHT VENTRICLE Tricuspids valve Pulmonary Aorta through pulmonary valve.THICKNESS OF WALL The wall of right ventricle is thinner than that of left ventricle in a ratio of 1:3SIZE OF CAVITYCavity of right ventricle is broader than left because of thin muscular walls, and both of these features are due to the fact that right ventricle has to pump the blood into lungs only against low pressure system (i.e. pulmonary circulation).FUNCTIONRight ventricle receives deoxygenated blood from right Atrium and pumps it to the lungs through pulmonary aorta for oxygenation.4. LEFT VENTRICLELeft ventricle is the most thick walled chamber and forms the apex of heart.OPENING OF LEFT VENTRICLE Bicuspid or Mitral valve Systemic Aorta through aortic valve.THICKNESS OF WALLThe walls of left ventricle are 3 times thicker than those of right ventricle. Blood pressure is 6 times high.SIZE OF CAVITYThe cavity of left ventricle is narrower than the right ventricle because of more muscular walls. It is due to the fact that left ventricle has to pump the blood to the entire body against high pressure system (Systemic Circulation).FUNCTIONIt receives oxygenated blood from left atrium & pumps it into the aorta.INTERNAL STRUCTURE OF VENTRLESInterior of ventricles show two parts1. Rough in flowing part2. Smooth out flowing part1. ROUGH PARTTRABECULAE CARNEAEInflowing part of each ventricle is rough due to presence of muscular ridges called as Trabeculae carneae.

2. SMOOTH PARTOut flowing part of each ventricle is smooth which gives origin to pulmonary trunk in right ventricle & Ascending Aorta in left ventricle.PAPILLARY MUSCLESPapillary muscles are the type of Trabeculae carneae being attached by their bases to ventricular walls, & their apices are connected to, the cusps of valves through chorda tendinae.CHORDA TENDINAE:These are delicate fibrous chords, which connect the papillary muscles to the cusps of Atriovertritcular valves.FUNCTIONChorda Tendinae don’t left the valves open back into the atria when the ventricles contract.SEPTUM OF HEART1. INTERATRIAL SEPTUMInternally, the right & left atria are separated by a vertical membranous septum called as Interatrial septum.2. INTERVENTRICULAR SEPTUM:The right & left verticals are also separated by a thick muscular septum called as Interventricular septum.3. ATRIOVENTRICULAR SEPTUMAtria lie above & behind the ventricles & are separated from ventricles by Atrioven-tricular septum.HEART VALVESHeart possesses two types of valves, which regulate the flow of blood with in the heart.TYPES OF HEART VALVES1. Atrioventricular valves -> Bicuspid, Tricuspid2. Semilunar vlaves -> Aortic valve, Pulmonary valve1. ATRIOVENTRICULAR VALVESINTRODUCTIONValves, which are present in b/w the Atria & ventricles are called Atrioventricular valves.TYPES OF ATRIOVENTRICULAR VALVESThey are of two types.1. Bicuspid or Mitral2. Tricuspid.1. BICUSPID OR MITRAL VALVEBlood flows from left Atrium to the left ventricle through left atrioventricular on orifice, which is guarded by bicuspid or Mitral valves.CUSPSIt has tow (2) cusps so it is called as bicuspid.2.TRICUSPID VALVEBlood flows from right Atrium to the Right ventricle through right Atrioventricular orifice, which is guarded by Tricuspid.CUSPSIt has 3 cusps so it is called as TRICUSPID.2. SEMILUNAR VALVES

This is the second category of heart valves, which guard the emergence of pulmonary & systemic Aorta.TYPES OF SEMILUNAR VALVESIt has Two Types:1. Aortic Valve2. Pulmonary Valve1. AORTIC VALVEThis valve guards the Aortic orifice in left ventricleCUSPSIt consists of 3 Semilunar cusps.2. PULMONARY VALVEThis valve guards the pulmonary orifice in right ventricle.CUSPSIt also consists of 3 semi lunar cusps.FUNCTIONS OF VALVESHeart valves maintain unidirectional flow of the blood & prevents its regurgitation in the opposite direction

Circulation of BloodCARDIAC CYCLE Sequence of events which take pace during completion of one heart beat is called “Cardiac Cycle”PHASES(I) DIASTOLEIt is resting period of heart chambers.II) SYSTOLEDuring which heart’s chambers contract. In cardiac cycle, blood is circulated in whole body.TYPES OF CIRCULATIONPULMONARY CIRCULATIONIn pulmonary circulation following events take place.RT. ATRIAL SYSTOLFirst the blood from whole systems of body, except lungs enter in right Atrium through superior and Inferior vena cavae into the right atrium by atiral systole,

blood comes into right ventricle from right atrium via Tricuspid valve.RT. VENTRICLE SYSTOLEAfter coming of blood into the Rt. Ventricle, it goes to the lungs via pulmonary trunk by ventricular systole, for oxygenation of blood by passing through pulmonary valve.SYSTEMIC CIRCULATIONIn systemic circulation, following events take place.LEFT ATRIAL SYSTOLEWhen oxygenated blood comes into left atrium, then left atrial sytole causes blood to enter left ventricle through bicuspid valveLEFT VENTRICULAR SYSTOLEWhen blood reaches here it sends into aorta through aortic valve to provide blood to body systems.CARDIAC OUTPUTThe blood volume pump per minute by left ventricle into the systemic circulationHEART BEATThe contraction of heart chambers are known heart beat which are regular, rhythmic.Ventricular systole is LUBVentricular diastole is DUBTIME FOR HEART BEAT0.8 sec is time for one heart beat.CONDUCTING SYSTEM OF HEARTIt consists of1.AV-NODE2.SA-NODE3)AV-BUNDLE4) PURKINJI FIBERS.1. SA-NODESA NODE found near upper end of superior vena cava in RT. atriumPARTS1. Specialized cardiac Muscles.2. Autonomic Nerve endings.FUNCTIONSIt Initiates the contraction of heart chambers through impulses & also transmit to AV node.2. AV- NODEIt is found in lower end of RT. Atrium. Structurally it is smilar to SA-NODEFUNCTIONIt transmit nerve impulses to ventricles for contraction rhythmically.3. AV-BUNDLEAV BUNDLE are the fibers originate from AV node. The bundle divided into Right AV bundle, Left AV bundleFUNCTIONIt transmit nerve impulses to ventricles.4. PURKINJI FIBERSAV bundles red divided into small fibres which penetrate the ventricle wall also

known as purkinji fibers / Bundle of His small thin fibers.LEUKEMIADEFINATION“The malignant disorder of increase number of abnormal leucocytes in blood.”CAUSEThe cause of leukemia is unknown.FACTORSFactors associated with leukemia are Ionizing Radiation Cytotoxic drugs. Retroviruses. GeneticEFFECTS OF DISEASE In result of leukemia, normal leucocytes counts become less. This is progressive, and fatal condition which leads to heamorrhage or infectionTHALASSEMIADEFINITION“Genetically impaired globin chains formation leads to impaired or defected formation of hemoglobin.”GENETIC DISEASEThalassemia is a genetic disorder, it may be1. Hetrozygous /Mild thalassemia:2. Homozygous.TYPEBETA – Thalassemiaα – ThalassemiaBETA-THALASSEMIAWhen globin chain is impaired or defected. It is most common one.ALPHA-THALASSEMIAwhen α-thalassemia globin chain of (HB) hemoglobin is defected.KINDS OF THALASSEMIATHALASSEMIA MINORWhen thalassemia is of heterozygous type with mild anemia.THALASSEMIA MAJORWhen thalassemia is of homozygous type with profound hypochromic anemia. It is more common in children & results with enlargement of kidney.REMEDYThe only remedy is transfusion of blood at regular intervals.CVD CARDIOVASCULAR DISEASEDiseases of heart, blood vessels and blood circulation are generally term as CVD.ATHEROSCLEROSISThe disease of arterial wall with lose of elasticity, thickness of inner wall causing narrowing of lumen, results in impairing of blood flow.ATHEROMATOUS PLAQUES

The narrowing is due to formation of fatty lesions called atheromatous plaque in inner lining of arteries.COMPONENTS OF PLAQUEThese plaques consist of LDL-LOW DENSITY LIPO PROTEINS DECAYING MUSCLES CELLS FIBROUS TISSUE PLATELETES CLUMP OF BLOODCAUSESSmoking, Hypertension, Obesity, Diabetes (Severe), family history of arterial diseaseEFFECTSAtherosclerosis produces no symptoms until the damage to artery is so severe that it restricts blood flow.ANGINA PECTORISIf blood flow to heart muscles is restricted causes (cell damage) necrosis called angina pectoris. Pain in chest, arm, or jaws usually during exercise.THROMBUS FORMATIONThe formation of blood clot with in the intact blood vessel initiated by atheromatous plaque.REASON FOR THROMBUS FORMATIONDue to formation athromatous plaque loss of elasticity, intact blood vessel get destroyed, blood from vessel wall comes out & later change to blood clot and blocks the lumen of small arteries.RESULT OF THROMBUS FORMATIONInitially thrombus block the lumen partially result in decrease blood flow to organs & leading to impairment of physiology of organs. Later on, thrombus blocks the lumen completely so due to complete loss of blood supply, cells damage occur.CORONARY THROMBOSISType of thrombosis when narrowing of lumen occurs in coronary blood vessels due to formation of clot.EFFECTOcculsion of coronary atery causes myocardial infarction and heart attack.HEAMORRHAGEThe escaping of blood from intact blood vessels.STROKEMost dangerous type of heamorrhage is that of brain which results in paralysis or strokes.HAEMATOMAThe accumalation of blood in interstitial spaces known as haematoma.This will lead to edema.STROKEDEFINITIONThe damage to the part of brain caused by, restriction in blood supply or leakage of blood outside the vessels.

CHARACTERISTICSImpairment of sensation, movement & function controlled by damage part of brain.CAUSES Hypertension AtherosclerosisHEMIPLEGIADamage to any, one cerebral hemisphere can cause weakness or paralyses of one side of body called hemiplegiaPRECAUTIONARY MEASURESBlood pressure should be with in normal range through proper diet. Salt should be used in less quantities exercise should be the regular habit. Smoking must be avoided. Person life should be free of worries.BLOOD VESSELSDEFINITION“The closed vessels or tubes through which transporting medium or blood circulate with in body called “blood vessels”.TYPES OF BLOOD VESSELS1. Arteries.2. Capillaries.3. Veins.ARTERIESDEFINITIONThick walled blood vessels which carry blood from heart to the organs of body.LAYERSIt consists of three layers.1. Tunica Externa/ Adventitia2. Tunica Media3. Tunica Intima1-TUNICA EXTERNAIt is thin but tough layer, having abundant amount of collagen fibers. It is outer most layer.2-TUNICA MEDIAThe middle layer has smooth muscle fibers & elastin fibers. It is the thickest layer.3-TUNICA INTIMAIt consists of squamous endothelium.LUMENThick walled vessels & having smaller lumen than that of veins except arteries of brain & related to cranium having large lumen.SEMILUNAR VALVESThey are not present in arteries.BRANCHES – DIVISIONSAorta divides into large arteries, large arteries into smaller arteries, smaller arteries into arterioles, then they give rise to capillary.At arteriole level, small sphincters are present which are known as PRE-CAPILLARY SPHINCTER.

SPHINCTERFUNCTIONThey are for regulating the diastolic pressure.CHARACTERSTICS Arteries are elastic so during systolic pressure, they do not rupture and dilate. During ceasement/ stopage of systolic pressure of heart, arteries contract & supply even flow of blood. The arteries carry oxygenated blood except pulmonary arteries.VEINSDEFINITIONThe thin walled blood vessels that drian blood from body parts/organs into heart called veins.LAYERSTunica ExternaTunica MediaTunica Intima1. TUNICA EXTERNAThickest layer in veins. It contains collagen, elastin and smooth muscles cells.2. TUNICA MEDIANot thicker as that of arteries. Elastic tissues and small smooth muscle.3. TUNICA INTIMAContains endothelial cells layer.LUMENIt has large lumen and thin wall.SEMILUNAR VALVESThey are present in veins to prevent back flow of blood in the influence of gravity.TRIBUTARIESVeninules -> small veins -> large veins -> vena cava.BLOOD PRESSUREIn veins blood pressure is low and are non pulsatile.CHARACTERISTICSThe blood flows slowly and smoothly in veins. Veins are superficial and collapse when empty.CAPILARIESThe intimate microscopic closed channels of both arterial & veinous interconnected network is called capillaries.DIAMETERCapillaries are extremely narrow in diameter of about 7-10 μ.LAYERSCapillaries are thin walled vessels & contains single layer of endothelium which offers small resistance in transport of material across the capillary wall.FUNCTIONThrough diffusion and active transport of oxygen is transported to tissues & CO2 to capillaries. Nitrogenous waste is filtered through the capillaries into excretory tubules.

BLUE BABIES (CYANOSIS)Blue baby is a layman terminology. In medical science it is known as cyanosis.DEFINITIONThe term cyanosis” means the blueish discolouration of the skin & mucous membrane due to excessive cone of reduced (deoxygenated haemoglobin) in the blood & it appears when reduced Hb conc in capillaries is more than 5 gm/dl of blood. The reduced Hb has an intense dark blue purple colour that is transmitted through the skin.MOST COMMON CAUSE OF CYANOSISAlthough there are various other causes of cyanosis but the most common cause is CONGENITAL CYANOTIC HEART DISEASE.BASIC CAUSE OF CYANOSISIn congenital heart diseases, there is an abnormal connection b/w right and left side of heart, which permits the large amount of unoxygenated venous blood to bypass the pulmonary capillaries & dilute the oxygenated blood in systemic arteries i.e RIGHT TO LEFT SHUNT, which results in cyanosis.SOME EXAMPLES OF CONGENITAL HEART DISEASES Some congenital heart diseases which are responsible for the abnormal connection between right and left sides of heart are as follows. ATRIAL SEPTUM DEFECT (ASD) VENTRICULAR SETPUM DEFECT (VSD) PERSISTANT DUCTUS ARTEROSUS In all these conditions, blood begins to flow from the aorta (left side) into pulmonary arteries (right side) & the people donot show cyanosis until late in life when heart fails or lungs become congested.TETRALOGY OF FALLOT (RIGHT –TO-LEFT SHUNT)It is the most common cause of cyanosis or blue baby in which aorta originates from right ventricles rather than left & receives deoxygenated blood.

Lymphatic SystemMAIN FUNCTION OF LYMPHATIC SYSTEM All body tissues are bathed in a watery fluid derived from the blood stream. This intercellular or tissue fluid is

formed when blood passes trough the capillaries. The capillary walls are permeable to all components of blood except the R.B.C’s & blood proteins. The fluid passes from the capillary into the intercellular spaces as the inter-cellular or tissue fluid. About 85% of the tissue fluid returns into the blood at the venous end of capillary. The rest 15 % of tissue fluid drains into lymphatic capillaries as lymph along with W.B.C’s, cell debris & micro organism like Bacteria , are transported back to the heart through lymphatic system.COMPONENTS OF LYMPHATIC SYSTEMLymphatic System Consists of1. Lymph2. Lymphatic tissues3. Lymphatic vessels or Lymphatics4. Lymph nodes (type of lymphatic tissue)DETAILS OF COMPONENTS1. LYMPHDEFINITION“Lymph is the name given to the tissue fluid once it has entered a lymphatic vessel. OR It can be defined as “Colour less body fluid that contains lymphocytes (agranular WBC’S), small proteins & fats”.EXPLANATIONLymph is a medium of exchange between blood & body cells. It takes the fluid substances from cell of tissues & intercellular spaces, which cannot penetrate the blood capillaries.2.LYMPHATIC TISSUESDEFINITION“Lymphatic tissues are a type of connective tissues that contain large no. of lymphocytes”ORGANS THAT CONTAIN LYMPHATIC TISSUESLymphatic tissue is organized into following structures (organs). Lymph nodes Thymus Spleen Tonsils Some of the patches of tissues in vermiform appendix & in small intestine.FUNCTIONLymphatic tissue is essential for immunologic defenses of the body against viruses & bacteria.3. LYMPHATICSDEFINITIONLymphatic vessels or lymphatics are blind tubes that assist the cardiovascular system in removal of tissue fluid from tissues spaces of the body, the vessels then return the fluid to the blood.AREAS WHERE LYMPHATIC ARE NOT PRESENTLymphatics are present in all tissues & organs of the body except. Central Nervous System

The eye ball Internal Ear Epidermis of Skin Cartilage & boneTYPESTwo Types of Lymphatics are there:-SMALL - LYMPH CAPILLARIESLARGE - LYMPH VESSELS.1. LYMPH CAPILLARIESDEFINITION“Lymph capillaries are a network of thin walled, anastomosing, microscopic vessels which are closed towards the tissue sinuses & drain the Lymph from tissues.”2. LYMPH VESSELSDEFINATIONThe capillaries are in turn drained by lymph tubes having larger diameters & beaded appearance, called the Lymph vessels.These vessels contain smooth muscles in them as well as Internal valves to prevent the back flow of Lymph. The Lymph circulates through the Lymph vessels by the contraction of surrounding skeletal muscles in one direction (towards the heart). These vessels converge into collecting ducts i.e rightLymphatic duct & thoracic duct that drain into large veins at the root of neck.4. LYMPH NODESDEFINITION“Lymph nodes are lymphoid tissue which are present through out the course of Lymphatics, through which the lymph must passes”INTERNAL STRUCTUREEach node consists of a thin, fibrous, outer capsule & an inner mass of lymphoid tissue.AFFERENT VESSELSSeveral small Lymphatics which carry the lymph into the lymph node are referred to as “Afferent vessels.”EFFERENT VESSELA single large vessel which carry the lymph away from the node is called “Efferent vessel”FUNCTIONLymph nodes act as filters that trap the microorganisms & other foreign bodies in the lymph. The Lymphocytes & macro-phages present here, neutralize & engulf the microorganisms, respectively.MAJOR FUNCTIONS OF LYMPHATIC SYSTEM.From Text Book Pg. 379.EDEMADEFINITION“Whenever the tissue fluid accumulates rather than being drained into the blood by the lymphatic system, tissue & body cavities become swollen. This condition is known as “Edema”.

TYPES OF EDEMAThere are two types of Edema.1. INTRACELLULAR2. EXTRACELLULAR1. INTRACELLULAR EDEMA“Accumulation of excess of fluid within the cells causing cellular swelling is called “Intra cellular Edema. It usually occurs after severe extracellular Edema.2. EXTRACELLULAR EDEMA“Excess fluid accumulation in extra cellular spaces is called Extracellular Edema. ”It is the most commonly occurring form of Edema.FACTORS CAUSING EDEMAAny factor that increases the tissue fluid high enough than normal value can cause excess tissue fluid volume causing edema. Some of these factor are as follows. High blood pressure Kidney failure Hart failure & etc.CAUSES OF EDEMAFollowing are three main causes of Edema.1. HYPOPROTEINEMIA (SEVERE DIETARY PROTEIN DEFICIENCY)When body is starving for Amino acids, it consumes its own blood proteins. This reduces the osmotic potential of the blood causing tissue fluid to accumulate in body tissues rather than being drawn back into capillaries, resulting in Edema.2. LYMPHATIC OBSTRUCITON (COMMONEST CAUSE –FILARIASIS )Another cause of edema is lymphatic obstruction, which results in more & more protein collection in the local tissue fluid hence, the increased volume. Commonest cause of lymphatic obstruction is FILARIASIS (infection by NEMOTODES) such condition is also called as “Elephantiasis” (because of swollen legs).3. INCREASED PERMEABILITY OF CAPILLARIES (CAUSES-BURNS & ALLERGIC REACTIONS)Sometimes the permeability of capillaries increase due to burns or allergic reactions, so blood proteins & plasma come out of capillaries & enter the tissue fluid thus causing Edema

Immune SystemIMMUNITY DEFINITION“The ability of human body to resist almost all types of micro-organisms, their toxins if any, foreign cells & abnormal cells of the body is termed as “Immunity”IMMUNOLOGYDEFINITION“The study of functioning & disorders of Immune system is termed as “Immunology”.IMMUNE SYSTEMImmunity is conferred to animals through the activities of the Immune System, which combats infectious agents.DEFINITION“Immune System is a collection of cells & proteins that work to protect the body from potentially harmful, infectious micro-organisms”MAIN FUNCTIONS OF IMMUNE SYSTEMProtection of body from all types of micro organisms & toxins that tend to damage the tissues and organs of body.ADDITIONAL FUNCTIONSImmune system also play important role in: Control of cancer Allergy Hypersensitivity Rejection problems when organs or tissues are transplanted.DIVISIONS OF IMMUNE SYSTEMImmune system can be divided into two functional divisions:1. Innate Immunity System2. Acquired Immunity SystemINNATE IMMUNITYDEFINITION“The NON SPECIFIC type of immunity which result from general processes , rather than from processes directed at specific disease organism (Such as antigen –antibody reaction) is called. INNATE OR NATURAL IMMUNITY & the system which is responsible for this type of immunity is called Innate IMMUNITY System.TYPES OF BARRIERS PROVIDED BY INNATE IMMUNITY SYSTEMThis system provides two types of barriers:Physical BarrierChemical BarrierPHYSICAL BARRIERS SKIN MUCOUS MEMBRANE & etc.CHEMICAL BARRIERS Lysozyme

Gastric juice (Acidic secretion of stomach) & etc.FIRST LINE OF DEFENCESkin, Mucous membrane & their secretions act as “First line of Defence”1. SKINThe intact skin provides an impenetrable barrier to the vast majority of infectious agents.2. MUCOUS MEMBRANESMost of the micro-organisms can enter only through the mucous membranes that lines the digestive, respiratory & urogenital tracts. However these areas are protected by movements of mucous & secretions (e.g Lysozyme in tears) to destroy many microbs.3. ACIDIC SECRETIONSMost of he microorganisms present in food or trapped in swallowed mucus from the upper respiratory tracts are destroyed by highly acidic gastric juice of stomach.SECOND LINE OF DEFENSEIf some how micro-organisms are able to penetrate the outer layer of the skin or mucous membrance, they encounter a second line of Defence offered by Innate Immunity system.It is non specific & comprises of1. PHAGOCYTES2. ANTIMICROBIAL PROTEINS3. INFLAMMATORY RESPONSE1. PHAGOCYTESPhagocytes are certain type of WBC’S which can injest internalize & destroy the particles including infectious agents.EXAMPLES OF PHAGOCYTIC CELLSNEUTROPHILSMACROPHAGESNEUTROPHILSNeutrophils (Polymorphonuclear Neutrophiles are short lived phagocytic cells which can ingest the bacteria or any foreign matter very actively.MACROPHAGES (BIG EATERS)The other phagocytic cells, the MONOCYTE can develop into large LONG-LIVED MACRO PHAGES when they reside in various tissues of body. ALSO CALLED AS ANTIGEN PRESENTING CELLS.Macrophages not only destroy individual micro organisms but also play a crucial rule in further immune response by “Presenting” parts of that microorganisms to other cells of immune system. For this reason, they are termed as “ANTIGEN PRESENTING CELLS.NATURAL KILLER (NK ) CELLSNatural killer cells (NK Cells ) are the large lymphocytes, which destroy the Virally infected own cells of the body Foreign cells Abnormal cells (cancerous cells)MECHANISM OF ACTION (CYTOTOXICITY)NK cells do not phagocytize the target cells, instead, they bind to their target

cells, release some PORE FORMING PROTEINS (PERFORINS), that literally punch large round holes in the membrane of attacked cells & eventually cause lysis of the target cells. This kind of destroying the target cells is called “CYTOTOXICITY”2. ANTIMICROBIAL PROTEINSEXAMPLES Important antimicrobial proteins are: Lysozyme Compliment proteins InterferonLYSOZYMESLysozyme, is a mucolytic polysaccharide that causes the LYSIS OF BACTERIA it is present in TEARS, SALIVA, & MUCUS SECRETION.COMPLEMENT PROTEINSComplement is a collective terms that describes a system of about 20 PROTEINS, many of which are INACTIVE ENZYME PRECURSORS. The principal actors in this system are 11 Proteins. All these proteins are present among the Plasma Proteins.ACTIVATION OF COMPLIMENT PROTEINSThese proteins can be activated by two ways. CLASSICAL PATH WAY-Act in Adaptive Immunity system. ALTERNATIVE PATH WAY- Act in Innate Immunity System.FUNCTIONSMain functions of compliment proteins are as follows:1. DIRECT LYSIS OF BACTERIA2. PROMOTE THE PHAGOCYTOSIS OF BACTERIA3. NEUTRILIZATION OF VIRUSES4. CHEMOATTRACTANTS FOR MACROPHAGES.INTERFERONS (ANTIVIRAL AGENTS)Interferon are secreted by virally infected cells or some lymphocytes to induce a state of ANTI VIRAL RESISTANCE in unaffected tissues of the body.3. INFLAMMATIONInflammation is the body’s reaction to an injury or by entry of micro organisms.EFFECTS OF INFLAMMATIONA cascade of chemical reactions take place during inflammatory response.1. When injured, BASOPHILS and MAST CELLS release a substance called HISTAMINE which causes. Increased permeability of adjacent capillaries. Local vasodilatation Increased leakage of capillaries.2. Due to CHEMOTAXIS, Phagocytes & macrophages are attracted at the injured site. Thus Phagocytes literally eat up microorganisms, dirt, cell debris & etc forming pus.SYMPTOMSRedness, heat, swelling, pain in injured tissue.FEVER -(ALSO CONTRIBUTES TO DEFENSE OF BODY)

In case of warm blooded animals, a no. of micro organisms who escape away from inflammatory response to infect some large part of the body, trigger FEVER. It is usually caused by WBC’S, that release the substance called as PYROGEN.FUNCTIONS High fever is dangerous but moderate fever contributes to the defense of the body. It inhibits the growth of micro-organisms. May speed up the repair of damaged tissues. Facilitates the phagocytosis, increase the production of interferons.ADAPTIVE IMMUNE SYSTEMDEFINITION“The specific type of Immunity which does not develop until after the body is first attacked by a bacterial disease or a toxin, is called “Adaptive or Acquired Immunity”. The system which provides this type of immunity is called “ADAPTIVE or ACQUIRED IMMUNE SYSTEM”

OR“Acquired Immunity is provided by special Immune System that form Antibodies & activated lymphocytes that attack & destroy the specific organisms or toxins. This is the THIRD LINE OF DEFENCE.DEVELOPMENT OF IMMUNE SYSTEM (LYMPHOCYTES ARE THE BASIS OF ADAPTIVE IMMUNE SYSTEM)Acquired Immune system is actually the product of body’s Lymphocytic system. The responses of adaptive Immune system is provided by Lymphocytes.TYPES OF LYMPHOCYTESDuring fetal development, all lymphocytes come from Bone Marrow. But depending upon their migration & maturity, they can be divided into two populations.1. “T” – Cells or “T” LYMPHOCYTES2. “B” – Cells or “B” LYMPHOCYTES.1. “T” LYMPHOCYTESDEFINITION“The lymphocytes that are destined to eventually form ACTIVATED “T” LYMPOCYTES first migrate to & then mature in THYMUS GLAND, that is why, they are called as “T” LYMPHOCYTES”FUNCTIONSThese are responsible for “CELL-MEDIATED IMMUNITY2. “B” LYMPHOCYTESDEFINITION“The lymphocytes that are destined to form ANTIBODIES are processed first in the LIVER (before birth) & then in BONE MARROW (after the birth). This population of cells was first discovered in birds where processing occurs in BURSA OF FABRICIUS (not found in mammals), hence they are called as “B” LYMPHOCYTES.”FUNCTIONSThese are responsible for HUMORAL IMMUNITY

ADAPTIVE IMMUNE SYSTEM IS INITIATED BY ANTIGENSIn order to develop a specific immune response, the immune system must recognize the invading organisms and / or foreign proteins from its self tissues & proteins.ANTIGENAny foreign substance, that elicit the immune response is called antigen. In general Antigens are proteins or large polysaccharides.RESPONSE OF IMMUNE SYSTEM TO ANTIGENThe immune system responds to an antigen by ACTIVATING LYMPHOCYTES & PRODUCING ANTIBODIES (Soluble Proteins). The antibody combines with antigen & helps to eliminate it from the body.BASIC TYPES OF ADAPTIVE IMMUNITYThe adaptive immune system mounts two types of attacks on invading micro-organisms.1. HUMORAL IMMUNITY2. CELL MEDIATED IMMUNITY (CMI)1. HUMORAL IMMUNITYDEFINITION“The immunity which is mediated by circulating antibodies produced by B-lymphocytes is called “ HUMORAL IMMUNITY”.

MAJOR FUCTIONS OF HUMORAL IMMUNITYHumoral Immunity provides major defence against “BACTERIAL INFECTIONSMECHANISM OF ACTION OF B CELLS“B” CELL RECEPTORSEach B-cell has specific type of antibodies on its cell surface. This antibody serves as ANTIGENIC RECEPTOR.ACTIVATION OF SPECIFIC “B” CELLSOn entry of foreign antigen, those B cells specific for that antigen enlarge immediately, becomes activated & form two types of cells:1. PLASMA CELLS2. MEMORY CELLS1. PLASMA CELLSThe activated B-cells proliferate rapidly & transform into enlarged effectors cells called plasma cells.FUNCTIONPlasma cells secrete ANTIBODIES into the circulation that help to eliminate that particular antigen.ACTIONS OF ANTIBODIES.After the formation of antigen-antibody complex antibody can inactivate the invading agent in one of the several ways. By activation of complement system that cause the Lysis. Direct Phagocytosis. Neutralization of the toxins released by bacteria. Agglutination of microorganism.2. MEMORY CELLSDEFINITION

Some of the activated B-cells don’t go on to form the plasma cells but instead, form moderate number of new B-cells, which don’t secrete antibodies such cells are called as Memory cells.

FUNCTIONSThe memory cells play important role in future immunity to this specific organism in case of re-infection.2. CELL MEDIATED IMMUNITY (CMI)DEFINITIONThe second type of acquired immunity is achieved through the formation of large number of Activated LYMPHOCYTES. This is called cell mediated or T-cell immunity.FUNCTIONS OF CMI CMI is responsible for delayed allergic reactions & rejection of transplantation of foreign tissue. It provides major defence against infections due to VIRUSES, FUNGI, TUBERCLE BACILLI & some parasites. It also provides defence against TUMOUR CELLS.MECHANISM OF ACTION OF “T”-CELLS.T-CELL RECEPTORS (TCRS)Antigens bind with specific RECEPTOR MOLECULES on the surface of T-Cells, in the same way that they bind the antibodies.ACTIVATION OF SPECIFIC “T” CELLS.On exposure to proper antigen, the “T” cells of specific type proliferate & release large no. of activated T-Cells.SEVERAL TYPES OF “T” CELLSDifferent types of T cells are classified into four major groups.1. HELPER “T” CELLS2. CYTOTOXIC “T” CELLS3. SUPRESSER “T” CELLS4. MEMORY “T” CELLS1. HELPER “T” CELLSHelper T cells are the MAJOR REGULATOR of all the immune functions.RECEPTORSHelper T cell receptors actually recognize a combination of antigen fragment & one of the body’s own self marker called. “MAJOR HISTO-COMPATIBILITY” (MHC) CLASS II molecules on the surface of macrophages or B cells.FUNCTIONSHelper T-cells secrete the LYMPHOKINES which stimulate the production of both CYTOTOXIC & SUPRESSER TOXINS.2. CYTOTOXIC “T” CELLS (KILLER CELLS)RECEPTORSReceptors on the surface of cytotoxic ‘T” cells recognize a combination of antigen fragment & self surface marker molecules called MHC CLASS I , found on every nucleated cells of its own body.FUNCTIONSThey are especially lethal to virally infected cells. They also destroy the cancer

cells, heart transplant cells & other foreign cells.3. SUPRESSOR “T” CELLSAlong with helper cells, In supressor, T-cells are classified as Regulatory T-CellsFUNCTIONSAfter the conquerence of infection, they seems to shut off the immune response in both B-cells & cytotoxic T-cells.4. MEMORY “T” CELLSDuring CMI response, some T-cells turn into MEMORY CELLSFUNCTIONMemory cells protect the body in case of reaction in future.TYPES OF IMMUNE RESPONSEThe immune system has also the ability to memorize the antigen it has encountered. Thus upon subsequent exposure to the same pathogen responds in two different ways.1. Primary Immune Response2. Secondary Immune Response1. PRIMARY IMMUNE RESPONSEDEFINITIONThe first exposure to an antigen to the immune system elicits formation of clones of effectors cells to develop specific immunity with in 5 to 10 days. This response of immune system is termed as Primary Immune response.CHARACTERISTICS DELAYED APPEARANCE WEAK POTENCY SHORT LIFE2. SECONDARY IMMUNE RESPONSEDEFINITIONSubsequent exposure of same antigen causes a much more rapid & much more potent antibody response. This is called Secondary Immune response. It develops to it max. with in 3-5 days.CHARACTERISTICS Rapid & quicker appearance Far more potent Longer duration (form antibodies for many months rather than for only a few weeks.)BASIS OF SECONDARY RESPONSE (IMMUNOLOGICAL MEMORY)The quicker secondary response is made possible due to ability called “Immunological Memory” of the immune system. It is based upon the long lasting memory cells produced with short lived effectors cells of pri immune response. The development of memory cells may provide life long protection against some diseases like chicken pox.ACTIVE & PASSIVE IMMUNITYACTIVE IMMUNITYDEFINITIONThe immunity which is acquired by own immune response is called active

immunityFUNCTION OF ACTIVE IMMUNITYActive immunity due to development of immunological memory provide LONG TERM PROTECTION, even in some diseases (e.g in chicken Pox ) life long protection is provided.TYPES OF ACTIVE IMMUNITYThere are two types.1. Natural active immunity2. Artificial active Immunity1. NATURAL ACTIVE IMMUNITYDEFINITIONWhen the active immunity is acquired as a consequence of natural infection then it is called Natural active immunity”2. ARTIFICIAL ACTIVE IMMUNITYDEFINITIONActive immunity can be acquired artificially by vaccination. In this case it is said to be “ARTIFICIAL ACTIVE IMMUNITY”PASSIVE IMMUNITYDEFINITIONTemporary immunity which is achieved in a person without injecting an antigen, by transferring the antibodies, activated T-cells or both obtain from another person or even an animal, is called passive immunity.FUNCTIONS OF PASSIVE IMMUNITYAlthough, acquired passive immunity is short lived (last for 2-3 weeks), it boosts the immune response of the victim several folds.TYPES OF PASSIVE IMMUNITYThere are 2 Types:1. Natural passive Immunity2. Artificial passive Immunity1. NATURAL PASSIVE IMMUNITYDEFINITIONWhen antibodies are transferred from one person to another of the same species during natural processes, then such immunity is called Natural passive immunity.

EXAMPLEA pregnant woman passes some of the antibodies to her fetus through placenta. The first breast feeding, the colostrum, of mother pass certain antibodies to her newly born infant.2. ARTIFICIAL PASSIVE IMMUNITYDEFINITIONPASSIVE IMMUNITY can also be transferred artificially by introducing antibodies derived from animals or human being who are already actively immunized to that disease. This is called artificial passive immunity.

EXAMPLERABIES is treated in man by injecting antibodies derided from persons who have been already vaccinated against rabies. This confers the rapid immunity

to combat the rapidly progressing rabies in new victim.IMMUNIZATIONThe process of inducing immunity as a preventive measure against certain infectious diseases is called immunization.ADVANTAGES OF IMMUNIZATIONThe incidence of number of diseases (e.g Diptheria, Measles) has declined dramatically since the introduction of effective immunization programmes. Some dread full diseases (e.g. Tuberclosis) is now under control.