BIOLOGY

Introduction to BiologyIntroduction to Biology

Lab Experimentation & Safety Lab Experimentation & Safety Characteristics of LifeCharacteristics of Life Scientific MethodScientific Method SI Units SI Units Tools Biologists UseTools Biologists Use

Lab Experimentation Lab Experimentation & Safety& Safety

Safety Contract Safety Contract Intranet Access to Intranet Access to Safety Manual Pg 75 Pg 75

Teachers Attend Safety TrainingTeachers Attend Safety Training August In-service

ActivityActivity: : Lab from Hell

Characteristics of LifeCharacteristics of Life Living things are made up of units called Living things are made up of units called cellscells..

Unicellular & multicellular Unicellular & multicellular Living thingsLiving things reproducereproduce..

Asexual & bisexualAsexual & bisexual Living things are based on a universal Living things are based on a universal genetic code called DNA.called DNA. Living things Living things growgrow & & developdevelop.. Living Living obtained/getobtained/get and and use materialsuse materials and and energyenergy

(metabolism).(metabolism). Living things things Living things things maintain an internal balancemaintain an internal balance

(homeostasis). This balance involves water, chemicals, and (homeostasis). This balance involves water, chemicals, and reactions with the organisms’ body.reactions with the organisms’ body.

Living things Living things change over timechange over time (evolution). (evolution).

Notes, Key, & Lab: Characteristics of Life

Scientific MethodScientific Method5 Steps5 Steps

1.1. State the problem State the problem

2.2. Form a hypothesis Form a hypothesis

3.3. Set up a controlled experimentSet up a controlled experiment independent variable (I change)independent variable (I change) dependent variable dependent variable Constants or controlled Constants or controlled

4.4. Record & analyze results Record & analyze results

5.5. Draw a conclusionDraw a conclusion

Lab ReportsLab Reports

Lab Activity: Lab Activity: Brand & Absorption

Notes & Key : Scientific Method; Activity and Key: Can You Spot the Scientific Method

SI Units SI Units •Metric System is a decimal system based on multiples of 10.

•M = Meter is the unit for length

•L = Liter is the unit for volume

•Cm3 = centimeters cubed is the unit for volume

•G = Gram is the unit for mass

•Degree or Celsius is the unit for temperature.

• Examples of Conversion Worksheet & Key

milli-milli-

drinkingdrinking chocolatchocolatee

milk.milk.MondayMondayDiedDiedHenryHenryKingKing

deci-deci- centi-centi-UnitUnit(m,L,g)(m,L,g)

Deca-Deca-Hecto-Hecto-Kilo-Kilo-

.001.001.01.01.1.111101010010010001000

Tools Scientist UseTools Scientist Use Triple Beam BalanceTriple Beam Balance Digital Electronic ScaleDigital Electronic Scale Ruler/Metric StickRuler/Metric Stick Goggles & ApronGoggles & Apron GlasswareGlassware

Graduated cylindersGraduated cylinders FlasksFlasks BeakersBeakers Slides & cover slipsSlides & cover slips

Forceps (tweezers)Forceps (tweezers) MicroscopesMicroscopes

LINK: Tool of the Life Scientist

MicroscopesMicroscopes Anton van Leeuwenhoek was the first man to use a Anton van Leeuwenhoek was the first man to use a

microscope to see living organisms.microscope to see living organisms. Types MicroscopesTypes Microscopes

Light Microscope & Compound MicroscopeLight Microscope & Compound Microscope Electron MicroscopeElectron Microscope

SECSEC TEMTEM

Monocular MicroscopeMonocular Microscope Binocular Dissecting MicroscopeBinocular Dissecting Microscope

Microscope and their FunctionMicroscope and their Function LAB: Microscope & Pond WaterLAB: Microscope & Pond Water

Links: Microscope Vocabulary Game

Classification

• Carolus Linnaeus• Taxonomic Hierarchy

– KPCOFGS– Binomial Nomenclature

• 6 Kingdoms• Using Dichotomous Keys

http://www.park.edu/bhoffman/courses/bi225/labs/Dichotomous%20Keys%202.htm

• Viruses- non-living, therefore not a taxonomic grouphttp://www.biology-online.org/1/9_pathogens.html

Notes & Key: Viruses

6 Kingdoms

• Archaebacteria previously Monera

http://www.cellsalive.com/howbig.htm

http://www.cellsalive.com/toc.htm#microbiol

• Eubacteria• Protista• Fungi• Plantae• Animalia

Links:

Comparing Kingdoms• Basic Structure: Prokaryotes vs. Eukaryotes• # Cells: Unicellular vs. Multicellular• Energy: Autotroph vs. Heterotroph• Cell Wall Composition: cellulose, chitin,

peptidoglycan  

Domain Bacteria Archaea Eukarya

Kingdom Eubacteria Archaebacteria Protista Fungi Plantae Animalia

Cell type

# cells

cell structures

mode of nutrition

example

EcologyEcology

PopulationsPopulationsEcosystemsEcosystemsSuccessionSuccessionHumans and the EnvironmentHumans and the Environment

Notes & Key: Ecology

Teacher Notes

PopulationPopulation

• Population sizePopulation size– Refers to the number of individuals in a Refers to the number of individuals in a

populationpopulation– Factors that influence this sizeFactors that influence this size

•Abiotic – nonliving, such as temperature, Abiotic – nonliving, such as temperature, moisture, air, salinity, and pHmoisture, air, salinity, and pH

•Biotic – all the living organisms that inhabit Biotic – all the living organisms that inhabit the environmentthe environment

• Population densityPopulation density– Refers to the number of individuals Refers to the number of individuals

found within a given areafound within a given area– If too wide spread, they rarely encounter If too wide spread, they rarely encounter

each other – difficult to reproduceeach other – difficult to reproduce

• DispersionDispersion– Refers to the way in which the Refers to the way in which the

individuals of the population are individuals of the population are arrangedarranged•Even – individuals are located at equal Even – individuals are located at equal

intervalsintervals

•Clumped – bunched together in clustersClumped – bunched together in clusters

•Random – location of each individual is Random – location of each individual is determined by chancedetermined by chance

• Population Growth – population grows Population Growth – population grows when more individuals are born than when more individuals are born than diedie

• Carrying capacity – when a population Carrying capacity – when a population has reached the maximum size that has reached the maximum size that the environment can supportthe environment can support– Size is determined by limiting factors Size is determined by limiting factors – Food, water, shelter Food, water, shelter

• Populations living areasPopulations living areas– Habitat = the area in which an organism Habitat = the area in which an organism

liveslives– Niche = the role the organism has in an Niche = the role the organism has in an

ecosystemecosystem

• Population relationshipsPopulation relationships– Symbiosis – close association between Symbiosis – close association between

two different types of organisms – a two different types of organisms – a scientific ‘living together’scientific ‘living together’•Mutualism – both organisms benefit (lichen)Mutualism – both organisms benefit (lichen)

•Commensalism – one organism benefits and Commensalism – one organism benefits and the other is neither harmed nor helped the other is neither harmed nor helped (epiphytes)(epiphytes)

•Parasitism – one organism benefits and the Parasitism – one organism benefits and the other is harmed (flea)other is harmed (flea)

EcosystemsEcosystems

• Energy FlowEnergy Flow– Producers - make their own food (green Producers - make their own food (green

plants, algae, some bacteria)plants, algae, some bacteria)– Consumers - obtain their food from others Consumers - obtain their food from others

•Herbivores – primary consumers that eat plantsHerbivores – primary consumers that eat plants•Carnivores – secondary consumers that eat fleshCarnivores – secondary consumers that eat flesh•Omnivores – secondary or tertiary consumers that Omnivores – secondary or tertiary consumers that

eat plants and flesheat plants and flesh•Decomposers – eat dead and decaying organismsDecomposers – eat dead and decaying organisms

• Food ChainFood Chain– Trophic levelsTrophic levels

•CloverClover

•RabbitRabbit

•SnakeSnake

•HawkHawk

• Food WebFood Web– Food chains that interconnectFood chains that interconnect– and overlapand overlap

• Pyramid of biomassPyramid of biomass– Total mass of organisms at each trophic Total mass of organisms at each trophic

levellevel

• Pyramid of numbersPyramid of numbers– Number of organisms at each trophic levelNumber of organisms at each trophic level

• Pyramid of energyPyramid of energy– Amount of energy at each trophic levelAmount of energy at each trophic level– Each trophic level receives ~ 10% from Each trophic level receives ~ 10% from

the next higher levelthe next higher level

• CyclesCycles– Water cycleWater cycle

•NonlivingNonliving– Condensation, precipitation, evaporationCondensation, precipitation, evaporation

•LivingLiving– Absorption, transpirationAbsorption, transpiration

• Carbon cycleCarbon cycle– Atmospheric carbonAtmospheric carbon– PhotosynthesisPhotosynthesis– Cellular respirationCellular respiration

• Nitrogen cycleNitrogen cycle– Atmospheric nitrogenAtmospheric nitrogen– Nitrogen-fixing bacteriaNitrogen-fixing bacteria– NitratesNitrates– NitritesNitrites– PlantsPlants– AnimalsAnimals– DecomposersDecomposers

• Oxygen cycleOxygen cycle– Oxygen in air and waterOxygen in air and water– Cellular respirationCellular respiration– WaterWater– PhotosynthesisPhotosynthesis

SuccessionSuccession

• Populations in an area are replaced Populations in an area are replaced by other populationsby other populations– Organisms make the environment less Organisms make the environment less

conducive for their existence and more conducive for their existence and more conducive for the next level conducive for the next level

• Primary succession – where life did Primary succession – where life did not exist beforenot exist before– Pioneer speciesPioneer species– Continuing species changeContinuing species change– Climax communityClimax community

– Ex. lichen, grasses, small bushes, small Ex. lichen, grasses, small bushes, small trees, mature softwoods (pines, balsams, trees, mature softwoods (pines, balsams, firs), mature hardwoods (oaks, hickories)firs), mature hardwoods (oaks, hickories)

• Secondary succession – where a prior Secondary succession – where a prior community was destroyed (by fire, community was destroyed (by fire, flood, volcanic eruption, abandoned flood, volcanic eruption, abandoned farming, mining, logging, etc.)farming, mining, logging, etc.)– Pioneer speciesPioneer species– Continuing species changeContinuing species change– Climax communityClimax community

Humans and the Humans and the EnvironmentEnvironment

• Conservation – Wise management of Conservation – Wise management of the Earth’s natural resourcesthe Earth’s natural resources– Renewable resourcesRenewable resources– Nonrenewable resourcesNonrenewable resources

• Renewable resourcesRenewable resources– WildlifeWildlife

•Many threatened or endangeredMany threatened or endangered

•Extinction occurs when a species disappears Extinction occurs when a species disappears from Earthfrom Earth

•Habitat destruction is major causeHabitat destruction is major cause

– ForestsForests• Becoming smaller due to increased demand for wood Becoming smaller due to increased demand for wood

and wood productsand wood products

• Deforestation occurs where large areas of forest are Deforestation occurs where large areas of forest are cut and cleared. Ex. tropical rainforestscut and cleared. Ex. tropical rainforests

– Cut and burned to clear land for farmingCut and burned to clear land for farming– Topsoil is thin, good for one, or maybe two, yearsTopsoil is thin, good for one, or maybe two, years– Then more must be clearedThen more must be cleared– When land is cleared, rain ceases as trees caused the When land is cleared, rain ceases as trees caused the

rain through transpirationrain through transpiration– Land becomes a desertLand becomes a desert

Reforestation is a solutionReforestation is a solution

• Soil – good soil is needed to grow Soil – good soil is needed to grow plants for food and for fibers to make plants for food and for fibers to make clothcloth– Erosion can be preventedErosion can be prevented

•WindbreaksWindbreaks

•Contour plowingContour plowing

•Terrace plowingTerrace plowing

•Strip croppingStrip cropping

•Crop rotationCrop rotation

• Nonrewable resourcesNonrewable resources– WaterWater

•Most importantMost important

•Cannot live without itCannot live without it

•WatershedsWatersheds

•DesalinationDesalination

Fossil FuelsFossil Fuels

Coal, natural gas, oilCoal, natural gas, oil

Alternative energy formsAlternative energy forms

solar energysolar energy

nuclear energynuclear energy

wind powerwind power

geothermal energygeothermal energy

water energywater energy

• PollutionPollution– Air pollutionAir pollution

• Most comes from burning fossil fuelsMost comes from burning fossil fuels

• Smog – smoke and fogSmog – smoke and fog

• Acid rain – oxides from burning fossil fuel combine Acid rain – oxides from burning fossil fuel combine with moisture in airwith moisture in air

• Temperature inversionTemperature inversion– Layer of warm air becomes trapped between layers of Layer of warm air becomes trapped between layers of

cool aircool air– Air pollutants become trapped in cool airAir pollutants become trapped in cool air– Do not rise form the earth, stay near groundDo not rise form the earth, stay near ground

– Water pollutionWater pollution•Agricultural runoffAgricultural runoff

• Industrial waste productsIndustrial waste products– One major example is hot waterOne major example is hot water– Causes thermal pollutionCauses thermal pollution– Hot water holds less oxygen than cold waterHot water holds less oxygen than cold water

– Land pollution – when people do not Land pollution – when people do not properly dispose of trashproperly dispose of trash•Destroys natural beauty of our landDestroys natural beauty of our land

•Killing animals that eat it or become trapped Killing animals that eat it or become trapped in itin it

•Recycling is an answerRecycling is an answer

•Some materials taken from:Some materials taken from:

•BiologyBiology by Dean Medley by Dean Medley

•The Living WorldThe Living World by George B. Johnson by George B. Johnson

Biochemistry

• Atomic Structure• Elements- CHNOPS• Water Chemistry• pH scale• 4 Major Groups of Macromolecules • Nature of Enzymes

Atomic Structure

Nucleus: protons and neutronsOrbitals: electrons, 8 electrons fills orbitalProtons + Neutrons = Atomic massIsotopes- differing # of neutronsProton # = Atomic Number = Electron #Atomic Mass # - Proton number = Neutron ## Electrons determines reactivity and bonding

Carbon easily bonds with several other atoms because it has only 4 electrons in outer orbital

Covalent bonds- electrons are sharedIonic bonds- electrons are lost or gained creating

ions which are attracted to each other

Links: http://www.chemguide.co.uk/atoms/properties/gcse.html Bohr Model

http://www.classzone.com/books/earth_science/terc/content/investigations/es0501/es0501page01.cfm

ElementsMost common in living things- CHNOPS

Water Chemistry/PropertiesPolarity and effect on bondingProperties-Excellent solvent, cohesive, adhesive, high specific heat,

high heat of vaporization, less dense when frozen

pH scale

0 7 14

acids neutral basic (alkaline)

Most living things prefer neutral pH

Strong acid

Strong base

Links: http://www.uni.edu/~iowawet/H2OProperties.html http://www.oceansonline.com/water_props.htm

4 Major Groups of Organic Molecules

 Carbohydrate

s Lipids Proteins Nucleic Acids

components C, H, O C, H, O C, H, O, N C, H, O, N, P

monomersmonosaccharide (ex-glucose)

fatty acids and glycerol amino acids nucleotides

Polymers examples & function

starch, glycogen (energy) cellulose, chitin (structural)

lipid bilayer (membranes) fat (stored energy, insulates)

hemoglobin (transport) enzymes (catalysts) antibodies (defense)...

DNA (direct protein synthesis) RNA (role in proteinsynthesis)

Enzymes

Enzymes are proteins that catalyze reactions. The reaction may build a larger molecule or breakdown a large molecule into parts.

Enzymes and substrates fit together like “lock and key”.

Reaction rate is also affected by temperature and pH because they may alter the shape of the enzyme.Links: http://www.lewport.wnyric.org/jwanamaker/animations/Enzyme%20activity.html

Lab: Catalase

Cells

• Cell Theory– Three Statements of Cell Theory

• All living things are made of one or more cells• The cell is the basic unit of life• Cells come from preexisting cells.

– Scientist who helped Develop Cell Theory• Robert Hooke – 1st Observed Cells (Cork Cells)• Anton van Leeuwenhoek – 1st to see living cells (in

pond water).• Matthias Schleiden – All plants are made of one or

more cells • Theodor Schwann – All animals are composed of

many cells• Rudolph Virchow – All cells come from preexisting

cells.

Cells continued

• Types of Cells– Prokaryotic

• Bacteria

– Eukaryotic• Animal• Plant

• Structure, Functions and Analogies of Cell Parts– Chart and Key– Note cards– Cell City

Cells continuedAnimal

Cells continuedPlant

Cell membrane

Cells continuedProkaryotic

Ribosomes

Cell Membrane

Cell Wall

Flagella

Chromatin (DNA)

Cells ContinueOrganelles

• In Animal & Plants– Nucleus– Nucleolus– Chromatin– Nuclear Membrane– Cytoplasm– Mitochondria– Golgi Apparatus (Complex)– Cell Membrane– Ribosomes– Lysosome– ER = Endoplasmic

Reticulum (Rough & Smooth)

– Vacuole

• Only in Animal– Centrioles

• Only in Plant– Cell Wall

– Chloroplast

– LARGE Central Vacuole

Activity and Key: Cell Chart

Cells ContinuedDiffusion & Osmosis

• Diffusion is the process by which molecules spread from areas of high concentration to areas of low concentration. When the molecules are even throughout a space - it is called EQUILIBRIUM

Osmosis• the diffusion of water

(across a membrane)

• Selectively Permeable - membranes that allow some things through, the cell membrane is selectively permeable, water and oxygen move freely across the cell's membrane, by diffusion

Video: “Osmosis Jones” by Warner Brothers Family Entertainment

Photosynthesis & Respiration

Photosynthesis

Equation CO2+H2O+light->C6H12O6+O2+H2O

Flow of energysun->producers (plants and algae)->consumers

Storage of energyGlucose molecule has stored energy

ChloroplastsSite of photosynthesis in eukaryotic cells

Autotrophic Organisms

Cellular Respiration (aka- Aerobic Respiration, Respiration)

EquationC6H12O6+O2+H2O->CO2+H2O+ ENERGY (ATPs)

Glucose is broken down, energy is released and tranferred into ATP molecules

ATPReadily available energy for cell use

Adenosine Tri Phosphate

MitochondriaSite of cellular respiration in eukaryotic cells

Autotrophic and Heterotrophic Organisms

General Overview info with helpful illustrations:

Links: http://www.phschool.com/science/biology_place/biocoach/photosynth/overview.html

http://www.phschool.com/science/biology_place/biocoach/cellresp/intro.html

The EvolutionThe Evolution

of Living Thingsof Living Things

Teacher Notes

What is a theory?What is a theory?

Based on educated Based on educated guessesguessesSupported by evidenceSupported by evidence

Believed by many to be Believed by many to be truetrueNOT a proven fact. Could NOT a proven fact. Could be disproved by new be disproved by new

evidenceevidence..

a characteristic that a characteristic that helps an organism helps an organism

survive and reproduce in survive and reproduce in its environment.its environment.

Three examples of adaptations are:Three examples of adaptations are:

structures for finding foodstructures for finding food

for protectionfor protection

for moving from place to placefor moving from place to place

Group of Group of organismsorganisms that that cancan matemate with one another with one another to produce to produce fertile offspringfertile offspring..

HOW MANY SPECIES EXIST?HOW MANY SPECIES EXIST?

Species of Hawaiian honeycreepers

Estimates of the Numbers of Species in the World

Source: World Conservation Monitoring Centre, Global Biodiversity - Status of the Earth's Living Resources, 1992.

Groups of Organisms

Species described

Maximum estimates

Most conservative estimates

Viruses 5,000 500,000 500,000

Bacteria 4,000 3,000,000 400,000

Fungi 70,000 1,500,000 1,000,000

Algae 40,000 10,000,000 200,000

Plants 250,000 500,000 300,000

Vertebrates 45,000 50,000 50,000

Nematodes 15,000 1,000,000 500,000

Mollusks 70,000 180,000 200,000

Crustaceans 40,000 150,000 200,000

Arachnids 75,000 1,000,000 750,000

Insects 950,000 100,000,000 8,000,000

•Scientists estimate the Earth is 4.6 billion years old•Fossil evidence shows that many species have died out and many new species have formed.

Process by which populations accumulate inherited changes over time.

FOSSILS- remains of organisms that have been preserved or petrified in sediment (sand, mud, or small rocks).

Newest/ Most Complex

Oldest/Simplest

““EVIDENCE” of EVIDENCE” of EVOLUTIONEVOLUTION

1.1. The Fossil RecordThe Fossil Record

2.2. Vestigial StructuresVestigial Structures

3.3. Comparing Skeletal Comparing Skeletal StructuresStructures

4.4. Comparing DNAComparing DNA

5.5. Embryonic StructureEmbryonic Structure

Vestigial Structures: remnants of once used structures.

Salamander

Baleen Whale

Boa Constrictor

Similar Skeletal Structures

Pterodactyl

Bird

Bat

Dolphin

Seal

Dog

Sheep Shrew

Human

Flying Swimming Running Grasping

Humerus

Ulna

Metacarpals

Radius

Carpals

Phalanges

The legendary dodo, a flightless bird extinct for more than 300 years, has yielded its DNA for the first time, and scientists say it is related to pigeons in Southeast Asia and even, though more distantly, to San Francisco's own flocks of the often-scorned scavengers. From a scrap of skin and a bit of bone, British biologists at Oxford University, together with an American graduate student from Georgia, have created a fascinating genealogy for the weird creature….

The genetic findings, along with the volcanic history of the islands in the Indian Ocean where the bird originated, show that the dodos probably descended from an unknown ancestral bird some 42 million years ago that flew from Africa to what are now the Mascarene Islands east of Madagascar.

Two separate species of descendants -- the dodo (Raphus cucullatus) and a close, flightless relative called the solitaire (Pezophaps solitaria) evolved some 26 million years ago. Millions of years later, they took roost on two separate Indian Ocean islands: the dodo on Mauritius and the solitaire on nearby Rodrigues.

DELICATE ANALYSISThe evolutionary history comes from a delicate and difficult kind of DNA analysis ….

Extinct dodo's DNA linked to pigeons British team tracks ancestry of humans' first evolutionary victim

 

David Perlman, Chronicle Science Editor

Friday, March 1, 2002                                              

EMBRYO DEVELOPMENTClosely related organisms look alike

during early development; they look different as they mature.

FOSSIL RECORD: A FOSSIL RECORD: A historical sequence of historical sequence of life indicated by fossils life indicated by fossils found in the layers of the found in the layers of the Earth.Earth.Gaps exist because Gaps exist because specific conditions are specific conditions are necessary to form fossils. necessary to form fossils. (Buried in fine sediment (Buried in fine sediment without oxygen.)without oxygen.)

DNA, RNA & Protein Synthesis

• DNA->RNA->Protein (flow of genetic information, gene expression,

central dogma)• History: Watson & Crick model • Structure of DNA • Meiosis/Gamete Production review • DNA Replication Steps• Importance/Function of Proteins• Protein Synthesis- mRNA, tRNA, rRNA

Chart and Key: Comparison of DNA and RNA

Teacher Notes: DNA, RNA, & Protein Synthesis

DNA

• Structure– Polymer of nucleotides – 4 nitrogen bases– Complementary bases/pair rules

• Replication– Unzip double strand – Each strand serves as template– Free nucleotides bond to templates– Form replicated chromosomes- relate to cell

cycle

•Link: http://www.lewport.wnyric.org/jwanamaker/animations/DNA%20Replication%20-%20long%20.html •Lab- build and manipulate DNA model

Proteins

• Strings of amino acids become proteins

• Proteins are the building blocks of life:– Structural– Enzymes– Hormones– Defense– Transporters

No life possible without proteins….

Protein Synthesis• Structure and Role of mRNA, tRNA, rRNA

• Transcription– Unwind DNA– Form mRNA complementary strand to gene– mRNA carries instructions to ribosome

• Translation– mRNA attaches to ribosome (rRNA)– tRNA brings amino acids to ribosome– Codons of mRNA determine anticodon of tRNA and

consequently the amino acid order.– Peptide bond form between amino acids and form

polypeptide– Polypeptide becomes functional protein

Link: http://www.lewport.wnyric.org/jwanamaker/animations/Protein%20Synthesis.html

Lab- Model process Activity- Draw, Color and label process Comparison of DNA and RNA table

• The Cell spends the majority of the time in Interphase of the Cycle Cycle

• The rest of the time it spends in Mitosis where the nucleus divides

• Once the nucleus divides, cytokinesis begins separating the cell in two

G2 (Makes new organelles)

G1 (Gets bigger)

S = Synthesis

P

M

AT

•Makes Body Cells (ex:Toe)•Cell division of the cell &

nucleus occurs•Cell division starts with one

cell & ends with two cells that are exactly like the original cell

• 4 Phases•Prophase – chromosomes appear clearly•Metaphase– chromosomes line in middle•Anaphase – chromatids pull apart and

cytokinesis begins•Telephase – chromosomes unwind and

cytokinesis ends

Chart & Key: Comparison on Mitosis & Meiosis

Links: Mitosis and Mitosis

NOTES: NOTES: MEIOSISMEIOSIS

Two Types of Cells• Body cells (diploid cells): full set

chromosomes Examples: all cells but sex cells

• Sex cells (haploid cells): half number chromosomes

Examples: egg (ova) = female sperm = male

HUMAN EXAMPLE:body cells = 46 chromosomes or

23 homologous pairssex cells = 23 chromosomes

(one from each pair) see fig. 9, pg. 114

When sperm fertilizes egg, each parent contributes 23 chromosomes (One from each homologous pair)

23 (female) + 23 (male) = 46 chromosomes total (23 homologous pairs)

How many TOTAL chromosomes does each fly have?

8

How many HOMOLOGOUS CHROMOSOMES does each fly have?

4

MEIOSISMEIOSIS•Cell division that makes sex cells.

•Chromosomes copied once

•Nucleus divides twice•1 cell makes 4Link: Meiosis Worksheet

SEX CHROMOSOMESSEX CHROMOSOMES• Carry genes that determine whether

offspring is male or female• In humans:

– XX = female• (egg only has X chromosome)

– XY = male •(sperm contains either X or Y chromosome)

FATHER DETERMINES GENDER!X passed on = girl, Y = boy

The passing of traits from parent to

offspring….Teacher Notes

http://www.tortuga.com/science/dna/genes.gif

HUMAN GENETIC INFORMATION

•Stored in 23 pairs of chromosomes

•Chromosome 1 = largest & is 3x bigger than chromosome 22.

•23rd pair of chromosomes = sex chromosomes (X or Y)

•Chromosomes made of DNA.•Genes = special units of

chromosomal DNA.

http://fig.cox.miami.edu/~cmallery/150/handouts/genes.gif

• CHROMOSOME 1: OVER 3000 genes

• CHROMOSOME 14: Approx. 1400 genes

• CHROMOSOME 19 Over 1700 genes

• CHROMOSOME 21Over 400 genes

TERMS TO KNOW• GENE: segments of DNA that carry

heredity instructions; located on chromosomes & passed on from parent to offspring.

• ALLELES: alternative (different) forms of a gene that governs the same characteristic. (One set of alleles from mom & one from dad.)

• GENOTYPE: inherited combination of alleles (The genes you have – one set from mom, one from dad!)

• PHENOTYPE: organisms inherited appearance (What you physically look like.)

IT’S A GAME OF CHANCE…• PROBABILITY: mathematical chance that

an event will occur.

• DOMINANT TRAIT: trait observed when at least one dominant allele for a characteristic is inherited.

• RECESSIVE TRAIT: trait that is observed when two recessive alleles for a characteristic are inherited.

HOMOZYGOUS v. HETEROZYOUS

• HETEROZYGOUS: If you have contrasting (opposite) pairs of genes for a trait. (Ex: you get a gene for attached earlobes from mom and unattached from dad.)

• HOMOZYGOUS: If you have two like (same) genes for a hereditary trait. (Ex.: you receive the gene from both parent that allows you to roll your tongue.)

WHAT ARE SOME TRAITS THAT ARE INHERITED?

Checking out your genes….

•Free earlobes are those that hang below the point of attachment to the head.  •Attached ear lobes are attached directly to the side

of the head.

FREE VS. ATTACHED EAR LOBES

Hairline: Widow’s Peak v. Straight

Chin: Dimple or No Dimple?

Thumb: Straight or Curved?

CHEEKS: DIMPLES OR NOTONE CHEEK WITH A DIMPLE IS A YES!

PINKY: BENT OR STRAIGHT?

Bent

Straight

TOES: LONGEST SECOND TOE OR LONGER BIG TOE?

TONGUE: ROLL IT OR NOT?

FOLDED HANDS: LEFT OR RIGHT THUMB ON TOP?

FRECKLES OR NOT?

A little about Mendel….• Lived during the 1800’s

• Austrian monk

• Noticed patterns of inheritance

• Studied the ways traits are passed from parents to offspring

• Discoveries not noticed for many years

MENDEL STUDIED PEAS

THREE REASONS:1. Grow quickly

2. Usually self-pollinating. (Have both male & female reproductive parts.)

3. Many varieties

CONTROLLED EXPERIMENTSCross-pollination: anthers (male) of one plant are removed so that it cannot self-pollinate. The pollen from another plant is used to fertilize the plant without anthers.

VOCABULARY:

• TRUE-BREED: A plant that always produces offspring with traits the same as the parent(s). Also called: PUREBRED or HOMOZYGOUS

• CROSS-BREED: Crossing two plants that had different forms of the same trait. (Example: white flower with pink flower.) Produces: HYBRID or HETEROZYGOUS

MENDEL’S 1st EXPERIMENT

•Studied 7 different characteristics

•Used true-breeding plants (ex. TT with tt)

•Each of the crosses was between two traits. (Example: flower color purple vs. white)

•The offspring were first generation. (F1)

A FEW OF THE TRAITS STUDIES BY MENDEL:

                                                                  

                                                                            

Similar results for each of the crosses – one trait always appeared the other trait seemed to disappear.

• DOMINANT: The name that Mendel gave to the trait that always appeared.

• RECESSIVE: The name that Mendel gave to the trait that seemed to disappear.

V

F F

f

f

Flower Color

F = purple f = white

FfFf

Ff FfQuiz Review

Some More Vocabulary:

•P generation: Parent Generation.

•F1 generation: First filial generation (i.e. 1st generation after parents)

•F2 generation: Generation produced from self-pollination of F1 generation.

MENDEL’S 2nd EXPERIMENT

•F1 generation allowed to self-pollinate.

•OUTCOME?? Recessive trait appeared.

•Recessive trait showed up again but not as

often as the dominant trait.

•Mendel calculated the ratio of dominant to

recessive. (3:1)

Each plant had two sets of instructions (genes) – one from each parent.

These two forms of the same gene are known as “ALLELES”.

V

F f

F

f

Genotype both parents = heterozygous

Parent 1 = Ff , Parent 2 = Ff

FfFF

Ff ff

Classification

• End of the year, after SOL– Material to cover

•Plant Phyla•Animal Phyla

– Mind Maps/Posters, Group work– Outdoor Scavenger hunts– Wildflower Collections

SOL Preparation

• http://www.pen.k12.va.us/VDOE/Assessment/releasedtests.html

• http://etest.ncs.com/Customers/Virginia/pat_home.htm

• http://www.virginiasol.com/test_grade10.htm

• http://schoolisland.com

Projects, Inquiry Investigation

• There are literally millions of website full of experiments.

• Easy experiments will teach scientific method and reinforce or introduce students to new biological concepts.

• Excellent websites for science activities:

Links: http://ei.cornell.eduhttp://www.epa.gov/epahome/educational.htm

SOURCES

• Holt, Rinehart, Winston. (2002) Life Science.

• Images: Google.com

• Movie: www.unitedstreaming.com