semester i - usbotp1 practical i plant … · 3 economic importance 6-7 4 range of thallus in...

Ramniranjan Jhunjhunwala College, Ghatkopar(W), Mumbai -86

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SEMESTER I - USBOTP1

PRACTICAL –I PLANT DIVERSITY I

(Algae, Fungi and Bryophyta)

Topics Sr.No Experiments Pg.No. Date Remarks

A: Algae 1 Nostoc 3

2 Spirogyra 4-5

3 Economic Importance 6-7

4 Range of thallus in Chlorophyta 8

5 Types of Chloroplasts 9

B: Fungi 6 Rhizopus 10

7 Aspergillus 11

8 Economic Importance 12

C: Bryophyta 9 Riccia 13

SEMESTER I - USBOTP1

PRACTICAL –II FORM AND FUNCTIONS

(Physiology and Cyto-genetics)

Topics Sr.No. Experiments Pg.No. Date Remarks

A.

Cytogenetics

10 Mitosis 14

11 Karyotype 15

a) Normal male 16

b) Normal female 16

c) Allium cepa 17

B. Cell

biology

12 Cell Inclusions

Starch grains; Aleurone layer 18

Cystolith , Raphides ;

Sphaeraphides

19


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Topics Sr.No. Experiments Pg.No. Date Remarks

13 Cell organelles

Plastids: Chloroplast and

Amyloplast

20

Endoplasmic reticulum 20

Nucleus 20

C. Ecology 14 Hydrophytes

Floating: Free Floating ;

Rooted floating);

Submerged

21

15 Hygrophytes 22

16 Mesophytes 22

17 Xerophytes (Succulent, Woody) 23

18 Halophytes 24

D. Biometry 19 Mean , Median and Mode 25-26

Frequency distribution

20 Graphical representation of data 27

Frequency polygon, histogram

and Pie chart

21 Standard deviation 28

Skeleton paper for semester I

29


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PRACTICAL-I

A) Algae

1. Nostoc

Division – Cyanophyta

Class – Cyanophyceae

Order – Oscillatoriales

Family – Nostocaceae

Genus – Nostoc

Occurrence – It is a common fresh water or terrestrial alga. Aquatic species are

found in ponds, pools or ditches. The terrestrial species grow on moist or wet soils

like rice fields.

Structure of thallus –

1) Nostoc filaments are unbranched and are found in colonies enveloped by

mucilaginous sheath.

2) The colonies may be small or large. A colony consists of a thick gelatinous

matrix in which are embedded a large number of contorted, beaded filaments

known as trichomes. A mature colony is hollow inside.

3) The colonies are referred to as Nostoc balls.

Trichome –

1) A single filament or trichome is uniseriate, moniliform (beaded) & contorted.

2) Each cell of the trichome is rounded or bead shaped and surrounded by a thin

layer of mucilage.

3) One or more heterocysts are present in the trichome. A heterocyst is larger

than the remaining cells and is thick walled. They are intercalary in position.

Heterocysts are connected to the adjacent cells by cytoplasmic connections

which later on get thickened to form polar nodules. The heterocysts help in

fragmentation and are centres of nitrogen fixation as they contain enzymes for

nitrogen fixation.


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2. Spirogyra

Division – Chlorophyta

Class – Chlorophyceae

Order – Zygnematales

Family - Zygnemataceae

Genus –Spirogyra

Occurrence – It is a fresh water alga found almost all over the world. It is one of the

most common green alga occurring chiefly in ponds, pools ditches and similar

places. It prefers still rather than running waters and is one of the free floating algae

known as pond scum. The filaments form floating masses buoyed up by bubbles of

oxygen.

Structure of thallus –

1) The plant body is filamentous. The filaments are unbranched, uniseriate, made

up of rectangular cells placed end to end. All cells in the filaments are

identical.

2) The filaments are covered with a mucilaginous sheath of pectose. There is no

distinction of base and apex.

Cell structure –

1) The cell is cylindrical in shape.

2) The cytoplasm is peripheral. Within the stratified cell wall of the cylindrical

cells, there is a lining of cytoplasm.

3) There is a large central vacuole which is traversed by cytoplasmic strands.

4) There may be one or more spirally arranged ribbon shaped chloroplasts with

unsmooth edges. Each chloroplast is studded with several pyrenoids.

5) In every cell there is one nucleus which is suspended in the center by

cytoplasmic strands or is embedded in the peripheral cytoplasm. The nucleus

contains a large nucleolus.

Sexual reproduction- is accomplished by conjugation – an aplanogametic isogamy.

Conjugation may be scalariform or lateral.


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Scalariform conjugation –

1) It involves two cells of two different filaments. The cells lying opposite each

other develop protuberances which grow and unite to form a conjugation tube.

2) When all the cells of two adjacent filaments form conjugation tubes, they give

the appearance of a ladder, hence called scalariform conjugation.

3) The protoplast of each cell contract and moves away from the cell wall to

form an aplanogamete.

4) In some species, both the gametes are active and unite in the conjugation tube,

forming a zygote.

5) In some species, one of the gametes is more active and moves through the

conjugation tube and unites with the inactive gamete. In such a case the

zygote is formed in one of the parent cells. The active gamete is usually

considered as male while the less active one as female.

Lateral conjugation –

1) In lateral conjugation, two adjacent cells of the same filament take part in

conjugation.

2) A conjugation tube is developed between adjacent cells.

3) The protoplast of the cells contract to form two gametes known as

aplanogametes.

4) One of the gametes moves through the conjugation tube into the other cell &

unites to form a zygote. The zygote is sometimes formed in the conjugation

tube.

5) As the conjugation tube is formed in the lateral wall, it is known as lateral

conjugation.

Zygospore – The zygote, which is formed after the union of two gametes, has a

diploid nucleus & oil rich cytoplasm. The zygote is enclosed by a thick wall which is

three layered & is known as the zygospore. It is highly resistant to cold and drought.

It is released by the decaying of the conjugation tube and sinks to the bottom of the

water body. It undergoes a period of rest.

------------------------------ Teacher’s Sign and Date


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3. Economic importance of algae

Biofuel – Ulva

1) It is a green, marine algae & found in cool water.

2) It grows attached to loose shells, pebbles, rocks, stones etc. and abundant in

estuaries and coastal areas affected by sewage pollution.

3) It is commonly known as ‘Sea lettuce’ or ‘Green laver’.

4) It has a thin, leaf- like thallus, resembling a salad leaf.

5) Algal biofuel is an alternative to fossil fuel that uses algae as its source of

natural deposits.Algae require nutrients, sunlight & water to grow. Algae

thrive on saline, brackish & waste water. For monoculture, waste water,

human & animal waste, plant waste, along with CO2 emissions from

industry, are transported to arid area Algaculture farms. After oil is extracted

from the algae , the algae residue is then used as an animal feedstock or as a

soil fertilizer.

6) It is one of the macro alga cultured for ‘algal biofuel’ which is highly

favourable to other biofuels. Algal biofuel has the potential to be a

sustainable, environment friendly alternative to diesel.

7) The lipid or oily part of the algal biomass are extracted and converted into

biodiesel.

Neutraceutical – Spirulina

1) Spirullina is fresh water, free floating blue green algae.

2) Its trichomes are multicellular, cylindrical without sheath and loosely or

tightly coiled into more or less regular coils. Cross walls are not distinct.

The terminal cells are rounded. It is mass cultured in Mexico, Taiwan &

India.

3) It is consumed as a dietary supplement (nutraceutical) as well as a whole

food.

4) It is rich in protein content (up to 65%) with all essential amino acids &

unsaturated fatty acids. It is rich in vitamin – K.

5) It is good meat substitute for vegetarian population.

6) It is a low fat, low calorie, cholesterol free source of protein. It does not

contain vitamin – C. It helps combat problems like diabetes, anaemia &

atmospheric pollution. It also has anti-oxidant properties.


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7) The gamma linoleic acid (GLA) present in Spirulina dissolves fat deposits

& reduces cholesterol.

8) In India, it is available as tablet prepared by CFTRI (Central Food

Technological Research Institute, Mysore).

Food – agar – Gelidium

1) Gelidium is a marine red algae.It is widely distributed small seaweed growing

attached to rocks. It forms an entangled mat of branched anastomosing

polymorphic axes which are sometimes leathery.

2) It is one of the good sources of Agar. Agar is a polysaccharide found in the

cell wall of the algae. It is a galactans and made up of galactose units.

3) Agar is used as bacteriological medium and for cell culturing and

microorganisms in the laboratories.

4) It is also used in food industry for making jellies and pharmaceutical

industries as stabilizing and protective agents.

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Teacher’s Sign and Date


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4. Range of Thallus

Range of thallus – Green algae show an extraordinary range of forms and shapes of the

plant body. The simplest ones are unicellular while the most complex ones resemble higher

plants. Some of the thallus forms are-

1) Unicellular and motile – It is the simplest form wherein the cell is oval or pear

shaped and is flagellated. Eg- Chlamydomonas

2) Unicellular and motile but colonial – The individual cells form a well organized unit

to form a hollow colony called Coenobium. Eg- Volvox

3) Unicellular non-motile coccoid - The cells are unicellular or colonial and are non-

motile. Eg- Chlorella, Scenedesmus

4) Filamentous unbranched – The cells are arranged in a filament placed end to end

and unbranched. Eg- Ulothrix

5) Filamentous branched – The cells are arranged in a filament placed end to end and

show lateral branches. eg- Cladophora

6) Parenchymatous thalloid – The cells form a parenchymatous thallus as a result of

cell division in more than one plane. Eg- Ulva

7) Heterotrichous forms- This is the most advanced type among Chlorophyta. Plant

thallus is differentiated into a prostrate system and an erect system. Eg- Chaetophora

8) Siphonaceous forms - A number of green algae are considerably enlarged without

any septation. Thallus is multinucleate and coenocytic and hollow in centre.

Eg- Caulerpa

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5. Types of chloroplasts

The most prominent feature of the cell is the chloroplast. Green algae show a variety of

shapes of chloroplasts. Moreover, the number of chloroplasts is also variable. Some of the

shapes of chloroplasts seen in green algae are-

Cup shaped – Chlamydomonas

Stellate – Zygnema

Ribbon shaped spiral – Spirogyra

Discoid – Cladophora

Reticulate – Oedogonium

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(B) FUNGI

Date: ------------

6) RHIZOPUS

Systematic position:

Division : Eunycophyta

Class : Phycomycetae

Sub – class : Alfagellatae

Order : Mucorales

Family : Mucoraceae

Genus : Rhizopus

Vegetative structure:

1) The fungus consists of white, cottony mycelia.

2) Mycelium is aseptae, coenocytic and branched.

3) In older mycelia the hyphae can be distinguished into 3 types –

a) Small branched hyphae penetrating the substratum are known as rhizoids

b) Horizontal branched hyphae are known as stolons and

c) Upright unbranched hyphe bearing sporangia are known as sporangiophores.

Asexual reproduction:

1) It takes place by formation of spores which are formed in sporangia.

2) The sporangia are club shaped on the tip of the sporangiophore.

3) Each sporangium is differentiated into inner columella and outer sporangial

region.

4) A large number of multinucleate thick walled black sporangiospores are

formed in this region.

5) Sporangiospore germinates to form new mycelium of Rhizopus.

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7) ASPERGILLUS

Systematic position:

Division : Eumycophyta

Class : Ascomycetes

Sub - class: Euascomycetae

Series : Plectomycetes

Order : Aspergillales

Family : Aspergillaceae

Genus : Aspergillus

General Characters:

1) Aspergillus forms yellowish patches along with Mucor and Penicillium.

2) The vegetative structure consists of well-developed, profusely branched,

septate and hyaline mycelia. The segments of mycelium are multinucleate.

3) Some hyphae penetrate the substratum and act as rhizoids, i.e. they absorb the

food material.

Asexual Reproduction:

1) Conidia are the asexual reproductive bodies formed on special branches called

conidiophores.

2) Each conidiophore arises from the foot cell of the mycelium.

3) The condiophore is elongated, unbranched, aseptate and terminates into a

bulbous structure called vesicle.

4) A number of bottle-shaped structures called sterigmata develop all over the

surface of the vesicle. Sterigmata is one-layered except in few species where it

is two-layered.

5) From each sterigma develops a chain of conidia which are basipetally

arranged.

6) Each conidium is spherical with spiny wall and a single nucleus.

7) When fully mature, they are carried away by wind and reaching a suitable

substratum germinate to form a new mycelia.

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8) Economic importance of fungi

Yeast Yeast is an important genus used in bakery industry.

It plays an important part in bread making as it causes fluffing of dough thereby

palatability and aroma of bread is increased.

Yeast is also used as food as it is rich in vitamins like Thiamin and Riboflavin etc.

In microbiological technique yeast are used in some media preparation as a source of

vitamins for microbes like bacteria and fungi.

Some species of Yeast cause skin infection in human and animals.

Mushrooms

Edible mushrooms like Agaricus campestris (Button mushroom), Pleurotus

(Oyster mushroom),Volvariella species and Boletus species are used in various

delicacies.

They are a rich source of vitamins and minerals and used in many food items like

Pizza and curries.

The edible species are cultivated commercially and supplied to market and hotels.

Deadly poisonous mushrooms are commonly known as” toad stools” like Amanita

are mistaken as edible mushrooms and have taken toll of life.

Wood rotting fungi – Bracket fungi

Bracket fungi are characterized by production of bracket or shelf shaped fruiting

body i.e. basidoicarp called as Conk.

Polyporus , Ganoderma and Oxysporus are the common examples of bracket fungi

responsible for white rot or brown rots of living or dead wood.

They are either parasitic or saprophytic and grow mostly on living or dead trees, logs

and stumps causing discoloration and disfiguring of texture thereby affecting the

quality of wood.

Some species of Ganoderma can form large thick basidiocarps causing death of tree.

Some other species of Ganoderma are cultivated commercially for human

consumption or medical use.

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C) BRYOPHYTA

9) Riccia

Classification

Division : Bryophyta

Class: Hepaticeae

Order: Marchantiales

Family: Ricciaceae

Genus: Riccia

Gametophyte: the gametophyte is prostrate, ribbon like and dichotomously

branched. The thallus is dorsiventrally flattened with a dorsal groove and a ventral

ridge. Repeated dichotomy forms rosette of Riccia.

Ventral view: there are two types of rhizoids in the median region. There are two

marginal rows of scales, which are violet in colour.

Rhizoids are of two types, smooth walled and tuberculated. In tuberculated rhizoids

inner wall layer develops peg (rod) like ingrowths in the lumen. Scales are one celled

in thickness.

T.S. of thallus: Thallus is differentiated into dorsal photosynthetic and ventral

storage region. Cells of photosynthetic filaments contain chloroplasts. Distal cells of

each filament is enlarged and together forms pseudo epidermis. Ventral storage

tissue consists of thin walled colourless cells containing starch grains. Some cells of

the ventral epidermis form unicellular rhizoids. Marginal scales can be observed.

T.S. of thallus passing through antheridium: Antheridium is embedded in the

antheridial chamber. It consists of multicellular stalk and oval body with single

layered sterile jacket and androgonial cells.

T.S. of thallus passing through archegonium: Archegonium is embedded in the

archegonial chamber. It bears a small stalk. Venter is one layered. Neck contains 4

neck canal cells while venter contains venter canal cell and an egg.

T.S. of thallus passing through sporophyte: The sporophyte is simple made up of

only capsule. Foot and seta are absent. The mature sporophyte shows tetrads of

spores. Outer layer of the spores shows honeycomb like markings.

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PRACTICAL II

Date: ------------

A) CYTOGENETICS

10) STUDY OF MITOSIS IN ONION ROOT TIPS

Aim : To study mitosis in the given planrt material.

Requirement : Root tips, 10 % HCl, Acetocarmine stain, slides, coverslips.

Procedure : Take a root tip and wash in water. Transfer the root tips in a watch –

glass. Treat the root tips with 1 % HCl to hydrolyse the cell wall and to separate the

cells from each other. After 10 minutes drain off HCl and wash the root tips with

water repeatedly for 4 – 5 times. Transfer the root tips on slide and add 2 – 3 drops of

acetocarmine stain. After 5 min. place a coverslip on the root tip and press it gently

so that the cells spread evenly. Blot the excess stain and observe under low power

and then under high power to see the different stages of mitosis.

Principle : Mitosis is an equational division in which each cell divides to form two

genetically identical cells. Mitosis mainly occurs during growth. Mitosis produces

daughter cells with same number of chromosomes as the parent cell. Various stages

of chromosomal separation can be observed.

i) Prophase: Spirally coiled thread – like chromosomes appear and nuclear

membrane dissolves.

ii) Metaphase: Chromosomes are arranged on the equatorial plane. Each

chromosome consists of two chromatids.

iii) Anaphase: Chromatids separate and move towards opposite poles.

iv) Telophase: Chromosomes reach at the poles. Two daughter nuclei are

formed by construction of nuclear membrane. Telophase is immediately

followed by the process of cytokinesis in which cytoplasmic division takes

place resulting in formation of two daughter cells.

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Date: ------------

11) Karyotype analysis

Aim: To study normal human karyotype.

Theory: Karyotype is the entire chromosome complement of the cell. In human there

are 23 pairs of chromosomes of which 22 chromosomes are autosomes and one pair

is of sex chromosomes. The sex chromosomes are X and Y. In human beings

autosomal chromosomes are present in two identical copies i.e. diploid (2n). Haploid

(n) cells have a single copy. The chromosomes are arranged and displayed in its

standard format known as idiogram. The arrangement is according to the size of the

chromosomes and position of the centromere. The 22 autosomes are divided into 7

groups as follows,

Group Length Position of centromere

A – Chromosome 1 to 3 Large Metacentric

B - Chromosome 4,5 Large Sub-metacentric

C–Chromosome 6 to 12 Medium Sub-metacentric

D –Chromosome 13 to 15 Medium Acrocentric

E – Chromosome 16 to18 Short Sub-metacentric

F – Chromosome 19, 20 Short Metacentric

G – Chromosome 21,22 Very small Acrocentric

H – Sex Chromosome 23 X-Medium

Y - Small

Submetacentric

Acrocentric


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Procedure:

1. Cut out the individual chromosome from the given karyotype.

2. Sort them out according to their size and position of centromere.

3. Then place the longest three metacentric chromosomes and label it is as group

“A”

4. Arrange the remaining chromosomes as per the respective groups.

a) Normal Male:

Human male shows 46 chromosomes out of which 22 pairs are autosomes while the

sex chromosome are dissimilar – one X chromosome and one Y chromosome.

b) Normal Female:

Human female shows 46 chromosomes out of which 22 pairs are autosomes while

the sex chromosome are similar – two X chromosomes.

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Date: ------------ Aim: To study onion karyotype.

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B) Cell Biology

12) Cell inclusions

These are non-living inclusions of the cell produced during the metabolic

activities of the cell. These non-protoplasmic substances in the cell constitute the

ergastic matters. They may remain in solution in the cell sap of the vacuoles or

dispersed in colloidal condition or as insoluble granules and crystals.

The ergastic matters are put into three groups, viz., 1) reserve materials,

2) secretory materials and 3) excretory material.

Reserve materials - These are food matter synthesized by the living cell and stored in

different parts of the plant. They can be carbohydrates, proteins and fats or oils.

Starch grains- are microscopic and each starch grain has a shiny refractive point

known as the hilum which is the starting point. Starch is deposited around the hilum

in layers which are called lines of stratification. The starch grains of different plants

show variations in the shape of the grain and the position of the hilum.

Potato – The hilum is located at one end and the deposition of layers is unequal.

Potato starch grains hence appear eccentric a grain with one hilum is simple.

Sometimes more than one grain may become adpressed with a few common lines of

stratification, such grains are compound.

Rice - The hilum is in the centre and the lines of stratification are formed around it

making the grain concentric. The grains in rice are angular or polyhedral.

Proteins – They are nitrogenous compounds of complex nature. The nitrogenous

compounds occur as soluble amino acids and insoluble proteid grains. In storage

regions they occur as aleurone grains. In cereals, a layer of cells just beneath the seed

coat (pericarp + testa) is filled with aleurone grains. This layer is referred to as the

aleurone layer. Eg- Maize.


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Excretory materials – These ergastic matters are by-products of metabolic

activities. Many of these materials are waste products and as plants do not have an

excretory system, they accumulate in the leaves, bark and seeds or fruits all of which

ultimately fall down. Excretory matters may be alkaloids, glucosides, tannins, latex,

resins, gums, mineral crystals etc.

Mineral crystals – Inorganic materials in the form of crystals occur as waste

products in many plants. They are mainly salts of calcium – as calcium oxalates and

carbonates.

Cystoliths – eg – Ficus

Crystals of calcium carbonate are found as aggregates in the form of a bunch of

grapes. A few cells of the innermost layer of the multiseriate epidermis enlarge and

the calcium carbonate aggregates on peg like projections of the cellulose wall form

cystoliths.

Raphides – eg – Pistia

Raphides are crystals of calcium oxalate. In Pistia these crystals are needle like or

acicular in the form of bundles and are located in special mucilage containing called

idioblasts.

Sphaeraphides – eg – Opuntia

These are calcium oxalate crystals which remain conglomerated together forming

roundish crystals called sphaeraphides or druses.

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13) Cell organelles

Plastids – are distinct organelles in plant cells and are embedded in the cytoplasm. They are

surrounded by membrane/s with colourless stroma inside. Plastids may be colourless –

leucoplasts or coloured – chromoplast.

Chloroplast – In higher plants, chloroplasts are predominantly present in the mesophyll

cells. They are generally lens shaped, about 2-4µm wide and 5-10µm long. There are about

20-40 chloroplasts per cell. Each chloroplast is surrounded by two membranes with inter-

membrane space. The inner part of the chloroplast is the stroma which is hyaline jelly like

semi-solid. The stroma is traversed by an internal membrane system called thylakoids. The

stacked thylakoids form the grana. The thylakoid membranes contain the photosynthetic

pigments. Light reactions take place in the thylakoid and dark reactions in the stroma.

Amyloplast – are colourless plastids that store starch. They do not contain any pigment.

They are large and irregular or spherical in shape. They are responsible for conversion of

simple sugars to insoluble starch grains for storage.

Endoplasmic reticulum – is a part of the endomembrane system of the cytoplasm. They

usually occur in three forms – cisternae, vesicles and tubules. The cisternae are elongated,

flattened and arranged in parallel lines, the vesicles are circular and the tubules are branched

and ramifying. Some endoplasmic reticulum appears rough on the outer surface due to the

presence of ribosomes (RER) while some ER is smooth (SER). The ER is continuous with

the nuclear envelope. The main functions of the ER are synthesizing, sorting and

transporting proteins as well as lipophilic secondary plant metabolites.

Nucleus – is a characteristic feature of eukaryotic cell. The interphase nucleus is

surrounded by a nuclear envelope which forms a boundary between the nucleus and the

cytoplasm. Included within the nucleus are 1) the chromosomes, which are present as highly

extended nucleoprotein fibers termed chromatin. 2) one or more nucleoli which are

irregularly shaped electron dense structures that fuction in the synthesis of ribosomal RNA.

3) the nucleoplasm, the fluid substance, in which the solutes of the nucleus are dissolved,and

4) the nuclear matrix, which is a protein containing fibrillar network.

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C) Ecology

14) Hydrophytes –

These plants grow in water and fresh water swamps. These plants may be completely

submerged in water – Hydrilla, Vallisnaria, Ceratophyllum etc.; free floating –

Pistia, Eichhornia, Lemna, Trapa, etc.; and rooted and floating – Nymphaea,

Sagittaria, etc.

A) Submerged hydrophytes – eg:- Hydrilla, Ceratophyllum, Vallisnaria.

1) These type of hydrophytes may be rooted (Vallisnaria) or free submerged

(Hydrilla). In rooted plants, roots are developed only for anchoring while in free

submerged plants roots are absent or very poorly developed as there is no anchoring

or water absorption. 2) Leaves are usually finely dissected or narrow ribbon shaped

and offer less resistance to water currents. 3) The stem is thin, wiry and green and

has tensile strength so that it can bend and not break. 4) The entire plant is covered

by mucilage to prevent decay.

B) Free floating hydrophytes – eg:- Eichhornia, Pistia, Trapa. 1) They have well

developed adventitious roots not for anchorage but for balancing the rosette of

leaves. Root caps are in the form of root pockets. Root hairs are absent. 2) Stem is

usually modified to an offset which is thick, fleshy and spongy. It also helps in

vegetative propagation. 3) Leaves are well developed but often show adaptations of

the aquatic environment. They have a waxy coating (Eichhornia) or many hairs

(Pistia) to prevent the wetting of leaf surface. They may be spongy or the petioles

may be swollen due to aerenchyma (Eichhornia), which give the plants buoyancy

and help them to float.

C) Rooted and floating hydrophytes – eg:- Nymphaea, Sagittaria. These plants are

rooted in the soil at the base of the pond but the leaves and flowers are floating on the

surface of water. 1) The roots are adventitious, arising from the underground rhizome

and are well developed the roots along with the rhizome anchor the plant in the water

logged soil. 2) The stem is modified to form an underground rhizome but it is spongy

as the soil is water logged.


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3) The petiole is very long and adapt to the depth of water. The lamina is thus always

above the surface of water. 4) The lamina is usually broad at the interface of water

and air. The upper surface is waxy to prevent wetting of the leaf surface. The lower

surface is covered by hairs and mucilage. The lamina is leathery in texture.

15) Hygrophytes - They are also known as amphibious plants as they grow in

shallow water. The underground parts are in water logged soil while the aerial parts

are well above the surface of water. Eg:- Typha, Scirpus.

1) Roots are well developed as they are in water logged soil which may later dry

up. They perform the function of anchorage and absorption of water and

minerals.

2) The stem is usually modified to a rhizome. The rhizome may be spongy in

nature when the soil is water logged.

3) The leaves in Typha are long, linear with a thick and tough exterior and spongy

interior. The tough exterior gives mechanical support to the long leaves while

the spongy interior is due to large air cavities. The air cavities in the lower part

of the leaf that is submerged in water may show diaphragm.

16) Mesophytes

They are ordinary land plants growing in situations which are neither too wet nor too

dry. There are usually no structural adaptations that are commonly seen in

hydrophytes or xerophytes. They can survive short dry spells.

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17) Xerophytes

They are plants growing in water scarce conditions. In order to endure the dry

conditions, xerophytes show adaptation to procure as much water as they can from

the dry soils and prevent excessive water loss from the aerial parts by way of

transpiration. On the basis of structural adaptations, xerophytes can be of two types –

succulents and non-succulents or woody xerophytes.

Succulent xerophytes – They are found in semi-arid regions. The plants are thick

and succulent or fleshy due to storage of water. Eg:- cacti (Opuntia), Aloe.

1) In cacti like Opuntia, the roots penetrate deep in the soil and have root hairs to

absorb water from the soil.

2) The stem is modified to a phylloclade which becomes thick and fleshy due to

storage of water. It also contains mucilage which has high water holding capacity.

Being green, it performs the function of photosynthesis. The phylloclade is covered

by a waxy layer to minimize water loss due to surface transpiration.

3) Leaves are reduced to spines, to reduce the rate of transpiration. Thus water loss is

minimized.

In plants like Aloe, the root system is very well developed for absorption of water.

The stem is stunted but the leaves long, thick and succulent. They are fleshy due to a

water storage tissue with mucilage for increasing the water holding capacity. The

leaves are often covered by a waxy cuticle to reduce transpiration.

Non-succulent xerophytes or Woody xerophytes – they are true xerophytes which

are found in dry soil atmospheric conditions. In extreme conditions of drought, the

plants become stunted. Eg:- Nerium

1) Woody xerophytes have a well developed and deep tap roots.

2) Leaves are the organs which show a very high degree of modification aimed at

reduction of transpiration.

3) In Nerium, the leaves are narrow and linear with a very thick cuticle to reduce

surface transpiration.

4) It shows many anatomical modifications like multiple epidermis for water storage

and restriction of stomata to stomatal pits only on the lower epidermis with a further

protection of hair to reduce the rate of transpiration.


FYBSc. Botany

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18) Halophytes

Plants growing in saline soils are known as halophytes. Mangroves are halophytes

growing in salt marshes along the coasts at estuaries. The characteristic adaptive

features of mangroves are:-

1) Formation of respiratory roots known as pneumatophores for efficient aeration as

the soil is water logged. The pneumatophores have small openings on the surface,

called lenticels for exchange of gases.

2) Formation of stilt like prop roots arising from the lower part of the main trunk of

the trees for efficient anchorage in the loose sandy soil.

3) Viviparous method of seed germination in which seeds germinate on the parent

plant before dropping as a seedling in the loose soil.

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FYBSc. Botany

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Table - 1

Obs. No.

(N)

Length of

leaves (cm)

Length of leaves in ascending order (cm)

(Xi)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Observations:

1) Mean –

2) Median –


FYBSc. Botany

26

Date: ------------

C) BIOMETRY

19) Determination of mean (arithmetic), median and mode.

Aim : To determine (1) mean (arithmetic), median, mode by using suitable plant

material.

Requirements : Nerium leaves (20 nos.) / Polyalthia branch (20 leaves), thread,

scale, calculator.

Procedure :

Measure the length of individual leaf lamina along the midrib from the base to the tip

and note the observation in the tabular form. Later arrange the data in ascending

order. By using this data calculate mean, median and mode.

Mean : It is defined as the average value of a given sample. It is denoted as X (with

proper unit)

Sum of all values ∑ Xi ∑ f x

Mean ( X ) = _______________________________

= -------- = --------

Total No. of observations N ∑ f

Median : It is defined as the central value or the middle observation. It is the value

of Xi obtained when the data is arranged in ascending of descending order.

For odd data (n+1)

Central Observation M = ---------- th observation

2

(n/2) + ( n/2 +1)

For even data, M = 2 th value


FYBSc. Botany

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Table - 2

The class interval with highest frequency is _________.

Mode: The mode is ___________ cm and is Unimodal/ Bimodal/ Multimodal

Class (cm) Class value

(X) (cm)

Tally Frequency (f) ∑fx (cm)


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Frequency distribution table: Steps

1) Arrange the data in ascending order.

2) Distribute the data in few classes. Number of classes should be made

conveniently by considering the range of data i.e. difference between the

largest value and smallest value.

3) Keep class interval same for each class and make classes with continuous

data.

4) For sample of 20 units make 3 or 4 classes.

5) Calculate the mid value i.e. class value of each class.

(Upper class limit – Lower class limit) /2 = Xi

6) By using tally marks count the number of observations falling in each class.

This is the frequency for each class.

7) Find the class with maximum frequency and class value of this class is taken

as mode value.

Mode : The observation or the class value that occurs with maximum frequency is

called mode. The data may be unimodal, bimodal or multimodal.

Result: Mean = ___________________ cm.

Median = ___________________ cm.

Mode = ___________________ cm.

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Date :

20) Determination of frequency distribution

Frequency distribution: The above data is divided into a number of class interval.

The central value of the class is called class value (x). The frequencies for the data is

determined. Frequency distribution can be shown graphically by histogram or

frequency polygon.

A bar graph plotted by taking class interval on x – axis and frequency on y – axis is

known as histogram.

If class value on each bar is joined, it is called as frequency polygon.

Construction of pie chart:

1. Refer to the frequency distribution table for the required data. (Refer Table 2)

2. Note the frequency of each class.

3. Take the sum of frequencies (N) as 360o.

4. Calculate the number of degrees for each class frequency by the following

formula

Class frequency/ N x 360 = ___________

5. Draw a circle and divide it into segments of class frequency according to the

measure of the angle.

6. Label each segment with its characteristic features or colour the sections.

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Observation Table

Class Class

Value Xi

f (Xi – X) = d d2 f d

2

∑ f d2

σ = -------

N

where N = total No. of observations


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21) STANDARD DEVIATION

Standard deviation is a statistical measure of the variability of the sample around the

mean value. It is root mean of total square deviation.

Use the frequency distribution table as data and calculate the SD.

Steps:

(1) Arrange the raw data in ascending order.

(2) Find out the Mean value X. (X bar)

(3) Calculate (X – Xi) = d (deviation from Mean) for each class value.

(4) Calculate the product f*d2

for each class.

(5) Take summation of fd2 ie ∑ f d

2

(6) Use the formula for sd (σ )

∑ f d2

σ (SD) = -------

N

where N = total No. of observations

(7) Estimate the standard deviation value and mention along with

mean value.

X ± sd (with proper unit )

(8) Smaller SD value indicate the uniformity in data while larger SD value

represent greater variability in the data.

Result :

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Skeleton Paper for External Practical Examination in Botany

FYBSc

Semester I Paper I (Skeleton Paper)

Total Marks: 50 Time: 2 hrs15 min

Q.1 Identify, classify and describe specimen A, B and C. Draw labeled sketches

to support your observations. (24)

Q.2 Identify and describe specimen/slide D, E, F and G (20)

Q.3 Journal (06)

A: Nostoc/ Spirogyra – Vegetative/Reproductive

B: Rhizopus/Aspergillus - Vegetative/Asexual

C: Riccia – Vegetative/ Reproductive

D: Range of thallus/ type of chloroplast from Chlorophyta

E: Economic importance of algae

F: Economic importance of fungi

G: Riccia – other than question 1

FYBSc

Semester I Paper II (Skeleton Paper)

Total Marks: 50 Time: 2 hrs15 min

Q.1 Prepare a squash of the given root tip ‘A’ to show various stages of

Mitosis. Draw neat labeled diagrams. (15)

Q.2 Make a preparation so as to show ------------- and -------------- in the given

plant material B and C. Draw neat and labeled sketches. (10)

Q.3 Performa the Biometry experiment D allotted to you. Record your

observations and results. (10)

Q.4 Identify and describe specimen/slide/photomicrograph E, F and G (09)

Q.5 Journal (06)

A: Onion root tip

B: Potato/Rice/Maize

C : Ficus/Pistia/Opuntia

D: Any experiment in Biometry

E: Photomicrograph of cell organelle

F: Hydrophyte/Xerophyte/Mesophyte/Halophyte/Hygrophyte

G: Karyotype

semester i - usbotp1 practical i plant … · 3 economic importance 6-7 4 range of thallus in...

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