BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.

TET

BIOLOGY (044) XII Practical (2023-24)

Part-A: Major Experiment: (5 marks)

Aim: Isolate DNA from available plant material such as papaya, banana, etc.
Principle: DNA is one of the nucleic acids found in living systems. DNA acts as the genetic material in
most of the organisms.
Requirements: Plant material papaya/banana, Water, Pastel and mortal, Chilled Ethanol (Refrigerate it
overnight), NaCl, Liquid detergent, Muslin cloth for filtration, needle, Beaker, Test tube, Petri dish.
Procedure:
1. Take the available plant material and grind it in the mortar or grate/mesh it to make paste in a petri
dish/beaker.
2. Fill a clean beaker with 25 ml of water, slowly add two teaspoons of liquid detergent and half teaspoon of
NaCl. Gently mix them without making bubbles till the salt dissolves.
3. Add this mixture to meshed plant material and let it undisturbed for 20 minutes to give detergent enough
time to react.
4. Place a fine/muslin cloth on a small beaker/boiling tube and carefully pour the mixture here and filter it.
Gently squeeze the mixture to get more liquid out. This liquid filtrate contains DNA.
5. Since the DNA is soluble in water so to isolate DNA from this filtrate pour chilled ethanol by side of the
test tube. (45 degree tilted)
6. After few minutes, DNA will isolate as white precipitates/ fine threads from the watery filtrate at the
boundary layer between water and ethanol.
7. Separate DNA by spooling i.e. the winding of the fine threads of DNA on needle.

Observation: DNA appears as white precipitate of very fine threads on the spool.
Precautions:
• All the glass wares must be thoroughly cleaned and dried.
• The chemicals used for the experiments must be of standard quality.
• NaCl and Liquid detergent should be to dissolve slowly by stirring without formation of foam or
bubbles.
• Add chilled ethanol to enable the precipitation of the DNA
• Use wire or blunt forceps for spooling of precipitated DNA.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

Minor Experiment (4 marks)

Aim: To study the plant population density by the quadrant method.

Materials Required:

• Nail.
• Thread
• Hammer
• Meter scale

Procedure
• Select a field to study the population density of the plants.
• Measure 1 meter × 1-meter area with the help of the meter scale in the field to make a quadrat.
• Fix four nails at the corner of the quadrat and tie each end of the nail using a thread.
• Similarly, make four more quadrats randomly in the field of the study.
• Count and mention the number of plants of a particular species in a square and similarly
mention the number of plants of another species if present.
• Now, count and add the total number of a particular plant species of all the square to get the
total number of a particular plant species of the quadrat.
• Repeat the same experiment for the other quadrats also.
• Record the data in the observation table.

Total number of individual(s) of the species in all the sampling unit (S)
Density =
Total number of sampling units studied (Q)

Observation

Total number of
individualsin all Total
Name Populatio
Number of plants in each quadrat the four number
of the ndensity
quadrats(S) of
plant (D)
Quadrats
species D=S/Q
(Q)
1 2 3 4
A
B
C
D
E

Conclusion
The population density is the highest for species A and the lowest for species C. The density value is
expressed as the number of individuals per unit area.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

Aim: To study plant frequency by quadrat method.

Material Required:

• Nails
• Meter scale
• Paper
• Thread
• Hammer

Procedure
• Select a field to study the population density of the plants.
• Measure 1 meter × 1-meter area with the help of the meter scale in the field to make a quadrat.
• Fix four nails at the corner of the quadrat and tie each end of the nail using a thread.
• Similarly, make four more quadrats randomly in the field of the study.
• Count and mention the number of plants of a particular species in a square and similarly
mention the number of plants of another species if present.
• Now, count and add the total number of a particular plant species of all the square to get the
total number of a particular plant species of the quadrat.
• Repeat the same experiment for the other quadrats also.
• Record the data in the observation table.

% Frequency = Number of sampling units in which the species occurs ×100

Total number of sampling units employed for the study

Observation

Total number of
quadrats in which Total
Name Percentag
Number of plants in each quadrat the species is number
of the e of
present of
plant frequency
(N) Quadrats
species F=N/Q x
(Q)
100
1 2 3 4
A
B
C
D
E

Conclusion
The population density is the highest for species A and the lowest for species C. The density value is
expressed as the number of individuals per unit area.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

Slide Preparation: (5 marks)

(Preparation of Temporary mount to observe Pollen Germination)

Aim: To study the pollen germination on slide.

Requirements:
Freshly plucked seasonal flowers Jasmine/lily/Hibiscus, beaker, boric acid, sucrose, microscope and glass
slide.
Procedure:
1. The first step involves the preparation of a sugar solution. This is done by dissolving 10g of sucrose 90ml
of water.
2. Pour a few drops of this solution onto the glass slide.
3. Then, use a brush or fingers to gently dust a few pollen grains from the stamen of mature flowers.
4. Let the slide set for 5 minutes.
5. Then, use the microscope to view the slides in 30- minute intervals.

Observation:
The pollen grains will germinate when submerged in the sugar rich nutrient medium. This is characterized
by the enlargement of the vegetative/tube cell. It emerges through one of the germ pores, eventually forming
a pollen tube. The generative cell nucleus grows into the pollen tube and makes two male gametes (sperm
nuclei). The male gamete is either spherical or lenticular in outline.

Precautions:
• Flowers should be freshly plucked.
• Use clean glass slide to observe the pollen grains.
• The slides should not be disturbed; otherwise position of pollen grains will get changed.
• During observations pollen grains must be properly dipped in nutrient solution.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

(Prepare a temporary mount of onion root tip to study mitosis)

Aim: Prepare a temporary mount of onion root tip to study mitosis.

Requirement: Onion bulbs, wide mouth glass tubes/jar/bottle, glacial acetic acid, ethanol 2-4%,
Acetocarmine stain, HCl, spirit lamp, slide, cover slips, blotting paper, molten wax/nail polish and
compound microscope
Procedure:
• Take a medium sized bulb of onion and trim off the old roots from the base by the help of sharp blade.
• Place the bulbs in a beaker containing water to grow the root tips for 4 to 6 days.
• Trim around 3 cm of the newly grown roots and place them in a watch glass.
• With the help of forceps, shift it to a vial holding freshly prepared aceto-alcohol i.e., a mixture of glacial
acetic acid and ethanol in the ratio 1:3
• Allow the root tips to remain in the vial for one complete day.
• With the help of forceps, pick one root and set in on a new glass slide.
• With the help of a dropper, allow one drop of N/10 HCl to come in contact with the tip of the root.
Additionally, add around 2 to 3 drops of the acetocarmine stain.
• Heat it lightly on the burner in such a way that the stain does not dry up.
• Excessive stain can be carefully treated using filter paper.
• Add a droplet of water to it.
• With the help of a needle, a coverslip can be mounted on it.
• Gently tap the coverslip with an unsharpened end of a needle in order for the meristematic tissue of the
root tip present under the coverslip to be squashed properly and to be straightened out as a fine cell layer
• The onion root tip cells’ slide is now prepared and ready to be examined for different stages of mitosis.
Observe and study mitosis by placing the slide under the compound microscope.
Observation:
1. Interphase:
The cells are mostly rectangular, oval or even circular in shape, with almost centrally situated densely
stained nucleus. The chromatic (coloured) material of the nucleus is homogeneous and looks granular. The
boundary of the nucleus is distinct. One or few nucleoli (sing: nucleolus) can also be observed inside the
nucleus.
2. Prophase
Intact nuclear outline is seen. The chromatin (seen as a homogeneous material in the nucleus at interphase)
appears as a network of fine threads (chromosomes). Nucleoli may or may not be visible.
3. Metaphase
The nuclear membrane disappears. Chromosomes are thick and are seen arranged at the equatorial plane of
the cell. Each chromosome at this stage has two chromatids joined together at the centromere. Nucleolus is
not observed during metaphase.
4. Anaphase
This stage shows the separation of the chromatids of each chromosome. The chromatids separate due to the
splitting of the centromere. Each chromatid now represents a separate chromosome as it has its own
centromere. The chromosomes are found as if they have moved towards the two poles of the cell. The
chromosomes at this stage may look like the shape of alphabets 'V', 'J' or 'I' depending upon the position of
centromere in them
5. Telophase
Chromosomes reach the opposite poles, lose their individuality, and look like a mass of chromatin. Nuclear
membrane appears to form the nuclei of the two future daughter cells

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

Precautions:
• The base of the onion bulb should be n contact with water while growing the roots.
• Clean the slide and coverslip thoroughly before use.
• Avoid air bubbles while putting coverslip on the slide.
• Root tips should be fixed in the morning between 8 to 10 am.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

Spotting (7)

1. Flowers adapted to pollination by different agencies (wind, insects, and birds).

• Flowers adapted to pollination by BIRDS

COMMENTS:
1. Pollination is the process of transferring pollen from the male anther of a
flowerto the female stigma of the same or different flower.
2. Pollination of flowers by birds is called ornithophily.
3. The flowers pollinated by birds are strong and are adapted to allow the
birds tostay near the flowers without their wings getting entangled in them.
4. The flowers are tubular and curved that facilitates nectar-sucking by birds.
5. The flowers are odourless and bright-coloured that attracts the birds.
Whilesucking the nectar, the pollen gets deposited on their beaks and
neck and is transferred to the plant they visit next.
6. Few examples of flowers pollinated by birds include: Hibiscus,
Bignonia,Verbenas,

• Flowers adapted to pollination by WIND

COMMENTS:
1. Pollination is the process of transferring pollen from the male anther of a
flowerto the female stigma of the same or different flower.
2. Most of the conifers and angiosperms exhibit wind pollination.
Pollination offlowers by the wind is called as anemophily.
3. Such flowers do not produce nectar and fragrance.
4. In the flowers pollinated by the wind, the microsporangia hang out of the
flower.As the wind blows, the light-weight pollen blows with it. The pollen
gets accumulated on the feathery stigma of the flower.
5. Few examples of such flowers include: Rice, Barley, Papaya, Maize,Oats

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

• Flowers adapted to pollination by INSECTS

COMMENTS:

1. Pollination is the process of transferring pollen from the male anther of a

flowerto the female stigma of the same or different flower.
2. Pollination of flowers by insects is called entomophily.
3. The flowers pollinated by insects are bright-coloured and produce nectar.
Nectarguides are present on the petals.
4. The fragrance of the flowers attracts the insects.
5. The pollens are sticky, large, heavy and rough so that stick to the body
of theinsects.
6. The stigmas are also sticky so that the pollens depositing are not dispersed.
Few examples of the flowers pollinated by insects are: Salvia, Datura, Gulmohar

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

2. Aim: To observe pollen germination on stigma through a permanent slide.

Materials Required

1. Microscope
2. Permanent slide

Procedure
The permanent slide is placed under a microscope and the pollen germination is observed.

Theory
Pollination refers to the transfer of pollen grains from the anther of a flower to the stigma of the same or
different flower through biotic or abiotic means. The complete process of pollination is as listed below:

• Once the pollen grains are deposited on the stigma, it starts to germinate with the absorption of
nutrients and water.
• A small pollen tube is produced through the style to the ovary.
• The tube cell moves out of the pollen grain and through one of the germ pores forms a pollen tube.
• The nucleus of the tube moves down to the tip of the pollen tube.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

3. . Identification of stages of gamete development, i.e., T.S. of testis and T.S. of ovary through
permanent slides (from mice).

T.S. OF TESTIS
CHARACTERSISTICS:
1. The testes comprise several seminiferous tubules embedded in the interstitial
tissues.
2. Thick fibrous tissues called tunica albuginea cover the testes.
3. It comprises different types of cells from the outside to the lunar in the
manner given below:
Spermatogonia → Spermatocytes → Spermatids → Spermatozoa (sperms)
4. Sertoli cells are located between the germinal cells.
5. The Leydig cells that produce testosterone are present in the interstitial
tissues.

T.S. OF OVARY
CHARACTERSISTICS:
1. An ovary is a germinal epithelium bounded by a solid structure covered by a
thick layer of fibrous tissue known as tunica albuginea.
2. It consists of an inner medulla and an outer cortex.
3. The medulla comprises several round or oval bodies known as ovarian
follicles.
4. Follicle development takes place in the following stages:
5. Primary follicle → Secondary follicle → tertiary follicle → Graafian follicle →
Corpus luteum
6. Cortex comprises corpus luteum along with mature follicles.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

4. Aim: Meiosis in onion bud cell or grasshopper testis through permanent slides

Theory:
• Meiosis is a double division which occurs in diploid cells and give rise to four haploid cells each having
half the number of chromosomes as compared to the parent cells.
• It occurs in cells that produce gametes in sexually reproducing organisms.
• The male gametes (sperms) are produced in testes and the female gametes (egg’s) are produced in the
ovaries through meiosis.
• Meiosis comprises of two division- meiosis I and meiosis II. Meiosis I result in reduction of
chromosomes number into half. i.e from 2n to n. hence is called reductional division. Meiosis II
maintains same number of chromosomes, hence is called equational division

Material/Apparatus Required:

• Permanents slides of different stages of meiosis

• Microscope

Procedure:

• Fix the permanent slide under the microscope.

• First observe it under the low power and then under high power of the microscope.

Observation:

Meiosis I (reductional division or heterotypic)

i. Prophase I
a. Leptotene: appearance of beaded chromosomes.
b. Zygotene: pairing of homologous chromosomes.
c. Pachytene: formation of tetrad, crossing over and chaismata formation.
d. Diplotene: Two chromosomes of each bivalent move away and chaismata disappears.
e. Diakinesis: nucleolus and nuclear envelope disappear and spindle begin to formed.
ii. Metaphase I: Formation of spindle and arrangement of chromosome at equator.
iii. Anaphase I: Separation of homologous chromosome and their movement towards the
opposite to poles of the spindle.
iv. Telophase I: Formation of two haploid nuclei.
Meiosis II (homotypic or equational division)
v. Prophase I: Sister chromosome of each chromosome begins to condense.
vi. Metaphase II: Formation of spindle, arrangement of chromosome at equator.
vii. Anaphase II: Movement of daughter chromosomes towards pole of spindle.
viii. Telophase II: Formation of two daughter nuclei from each daughter cell formed by meiosis I.
Cytokinesis: division of cytoplasm resulting into four haploid daughter cells form a diploid cell.

Precautions:

1. First observe the slide under low power and then under high power of the microscope.
2. Use fine adjustment of the microscope for focusing the slide under high power.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

5. T.S. of blastula through permanent slide (Mammalian).

CHARACTERSISTICS:
1. The zygote undergoes a few cycles of mitotic divisions to form a solid ball of cells called morula.
The cellscontinue to divide and at a later stage a cavity is formed within it. This stage is blastula.
2. Blastula appears as a sphere with a cavity known as blastocoel.
3. An outer layer of blastomeres known as trophoblasts is observed.
4. One end of the blastula shows a cellular mass adhered to the trophoblast. This is known as the
inner cell mass.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

6. Aim: Mendelian inheritance using seeds of different colour/sizes of any plant

Theory:

Mendel hybridized or crossed pollinated plants with alternate forms of one or more traits. He
performed monohybrid, dihybrid and polyhybrid crosses and formulated basic law of heredity. These
laws are:

1. Law of dominance: when two factors (genes) of a pair of contrasting characters are bought
togetherin a cross, only one of them express itself in the resulting hybrids. The character expressed
is said to be dominant and the other which remains suppressive is called recessive.
2. Law of segregation: two factors (alleles) of charters separate or segregate from each other during
gamete formation and the paired condition is restored by the random fusion of gametes during
fertilization.
3. Law of independent assortment: when the factors (genes) for different characters inherited from
parents, do not remain linked in the offspring, but their distribution in the gametes and in the
progenyof subsequent generation is independent of each other.

The characters which follow the Mendel laws during inheritance are called mendelian traits.

Material/Apparatus Required:

• Peas seeds samples

• Petri dish
• Notebook
• Pencil/ pen

Procedure:

• Take about 100 pea seeds in a tray.

• Separate out round and wrinkled and put in separate Petri dish
• Note down the number of round and wrinkled seed and calculate their appropriate ratio.
• Repeat the process for the other contrasting traits of the seed i.e., yellow and green colour.

Observation:

Sr. Character / traits of the seed Total no. of No. of seed showing Appropriate
no. seed observed contrasting form of the trait ratio
1 Seed shape (Round/ wrinkled)
2 Seed shape (yellow/green)

Result:

The contrasting forms in both the traits of pea seed (i.e., seed shape and seed colour) show an
approximate ratio of .

Precautions:

Observe the contrasting traits carefully and take sufficient large number of seed for analysis to minimize
theerror.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

7. Prepared pedigree charts of any one of the genetic traits such as rolling of tongue,
blood groups, ear lobes, widow's peak and colour blindness.

Pedigree Analysis

Pedigree analysis is the analysis of traits in several generations of a

family. The inheritance of a particular trait is represented in the family
tree over generations. It is a strong tool to trace the inheritance of a
specific trait abnormality or disease. Some specific symbols are used to
show pedigree in a pedigree chart.

Significance of pedigree analysis

• It can be used to track and trace the inheritance of a character.

• It can be used to trace the pattern of inheritance of trait of
abnormality or disease.
• It has been used by genetic counsellors to inform the couples, if
their child will have any genetic defect or not.

WIDOW'S PEAK

COMMENTS:

1. Widow's peak is a hairline that forms distinct peak on forehead, it is an Autosome Linked
Dominanttrait.
2. Transmission of traits occurs from parents of either sex. Males and females are equally affected.
3. The pedigree is vertical, i.e., the trait is marked to be present in each of the generations.
Multiplegenerations are characteristically affected.
4.

(AUTOSOMAL DOMINANT)

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

ROLLING OF TONGUE & FUSED EAR LOBES:

COMMENTS:

1. Rolling of tongue (Ability to roll tongue in U shape) & fused ear lobes (Ear lobes attached to
head) arean Autosome Linked Recessive trait.
2. Occur in equal proportions in multiple male and female siblings, whose parents are normal but
carriers;
3. The siblings are homozygous for the defective allele, but their parents, though some may
appearnormal, are obviously heterozygous, i.e., are merely carriers of the trait.
4. Consanguinity (marriage between man and woman genetically related to each other, such as
cousins)occasionally results in the appearance of such traits.

(AUTOSOMAL RECESSIVE)

COLOUR BLINDNESS:

COMMENTS:

1. Red-green colour blindness is an example of Sex (X- chromosome) linked recessive trait.
2. Females express the trait only when they are homozygous for the mutant allele, whereas the
males doso even when they are hemizygous for it.
3. About half of the sons of the carrier (heterozygous for the trait) females are affected. In case of
homozygous females showing the trait, fifty percent of her daughters and all of her sons are likely
to beaffected. Therefore, the males are most affected in the population.
4. This trait shows cris-cross inheritance or skipping of generation.

(SEX-LINKED RECESSIVE)

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

BLOOD GROUP:

COMMENTS:

1. Inheritance of Blood group is an example of Dominance, Multiple allelism and co-dominance.

2. Gene for ABO blood group having 3 alleles: IA, IB and Io in which IA and IB are dominant while Io
isrecessive.
3. It is independent of sex of the organism.

(SEX-LINKED DOMINANT)

Y-chromosome Linked Traits

1. The gene for such traits is present on the Y-chromosome.

2. Any trait linked to Y-chromosome is found only in males and not in females because the Y-
chromosome is present only in males.
3. All the sons of the affected male exhibit the trait, whereas, none of the daughters exhibits the trait.
4. Eg: Male Pattern baldness, Hyper Trichosis etc.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

8. Aim: Controlled pollination - emasculation, tagging and bagging

Theory:

1. Plant breeding is a science of changing and improving the heredity of plant ans production of new
varieties which are far better than original type.
2. Hybridization is a method by which improved varieties of economical important plants/crops
areproduced by crossing two or more genetically different plants.

A. Emasculation
Material/Apparatus Required: forceps or scissors method of emasculation.

Comment

• This method is employed in the crops having flower sufficiently large size.
• The instrument used in this method includes pocket lens, forceps, needle, scissors, scalpel,
hairbrush, etc.
• In this process anther are removed from flowers before their maturation.
• The anthers are cut with the help of sterilized forceps’s or scissors.
Material/Apparatus Required: Hot or cold water and alcohol

Comment
• This method of emasculation is employed the crop having small flowers like paddy, sorghum, etc.
• In this method the penicles (clusters of flowers are dipped in hot water (44 - 45°C) for 1 -10
minutesto kill the anthers.
• In the same way emasculation is done with cold water or alcohol.

B. Tagging and Bagging

Material/Apparatus Required: Bagging, tagging and labelling.

Comment

• After emasculation, the flower are covered with small bags to prevent pollination with
undesiredpollen grains.
• These bags are made up of polyethene, paper, muslin cloth or parchment paper.
• The bags are punctured or made perforation so as to provide aeration to the flowers.
• The flower of male parents are also protected in bags to prevent mixing of their pollen grains
with foreign pollens.
• After dusting of the desired pollen grains on the emasculated flowers, the bags are re-tagged.
• A label of paper is tagged on the plant which display the date of emasculation, crossing and
briefaccount of the parent.

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

9. (Common disease - causing organisms like Ascaris, Entamoeba, Plasmodium, ringworm through
permanent slides, models or virtual images. Comment on symptoms of diseases that they cause.)

1. Identification: Ascaris
Systematic position:
Phylum – Aschelminthes
Class – Nematoda
Genus – Ascaris
Species- lumbricoides
Characteristics:
• It has a long, cylindrical and un-segmented body.
• The male and female organisms are separate.
• It bears a mouth at the anterior end surrounded by three lips.
• There is an excretory pore on the ventral surface slightly behind the anterior end.
• A pair of penial spicules are present in the male worms close to the cloacal opening.
• The female genitals are present at about one-third distance from the anterior end.

Disease: Round worm or Ascaris is one of the common parasites found in the intestine of human beings that
causes Ascariasis.
Symptoms: (a) Irregular bowel, (b) Occasional vomiting, (c) Anaemia (d)Abdominal cramping & swelling
(e) Nausea

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BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

2. Identification: Entamoeba
Systematic position:
Phylum: Protozoa
Class: Rhizopoda
Genus: Entamoeba
Species: hystolytica
Characteristics
• It is a unicellular organism with an irregular shape.
• It consists of a few food vacuoles. The contractile vacuole is absent.
• Cysts with four nuclei are present.
• It consists of a nucleus located eccentrically in the cell.

Disease: Entamoeba histolytica is an organism found in the intestines of humans that is responsible for
causing amoebic dysentery.
Symptoms: Abdominal pain, Watery diarrhea with mucus, blood and pus, Fatigue, Fever, Nausea, Vomiting

3. Identification: Plasmodium
Systematic position:
Phylum: Protozoa
Class: Sporozoa
Genus: Plasmodium
Species: vivax
Characteristics
• It is a unicellular endoparasite found within the red blood cells of the diseased person.
• The parasite is mostly diagnosed at the “signet ring” stage where the parasite appears as a round
body.
• There is a big vacuole present inside the cell. The cytoplasm is accumulated at one place and
contains the nucleus.
• Plasmodium vivax is a protozoan parasite that causes malaria in humans. The infected female
anopheles bites a healthy person and transmits the sporozoite into the peripheral blood vessels of
humans.

Disease: The infective stage sporozoites causes the disease Malaria. This stage undergoes several rounds of
multiplication in liver and erythrocytes of Human.
Symptoms: High fever, shaking chills, Headache, Vomiting, Nausea.

Contacts: Suman Debnath, Ph-7687931008. E-Mail: sumandebnath98@gmail.com, Class: XII Page 19

BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

10. Objective: To study symbiotic association in root nodules of leguminous plant,

cuscuta on host and Lichens through model / specimen/ chart
1. Symbiotic association in root nodules of leguminous plant

• Rhizobium bacteria are present in root nodules of leguminous plant and form a symbiotic relationship,
mutualism, where both are benefited from each other. Nitrogen fixing bacteria like Rhizobium fixes
atmospheric nitrogen into nitrogenous compounds
• Rhizobium can convert atmospheric nitrogen to ammonia that can be used by pea plant for growth and
development.
• Bacteria receive nutrients and suitable place to grow from plant.
2. Cascuta

• Cuscuta commonly called dodder or amerbel and live as stem ectoparasite onother plants.
• Cuscuta has no fully expanded form of leaves (scale like leaves are present)and has no
chlorophyll.
• Stem of cuscuta is thin and slender shaped and It winds around the stem of host plant.
• Stem of cuscuta fixes itself to the stem of host plant with specialstructures called Haustoria
• It forms direct connection to the vascular bundles of the host andwithdraw water, carbohydrates
and other solutes.
3. Lichen
• Lichens are composite organisms representing a
symbiotic association (mutualism) between fungus
and algae
• The algal component is known as phycobiont and fungal
component is known as mycobiont.
• Algae prepare food for fungi and fungi provide shelter
and absorb mineral, nutrients and water forits partner.
• They grow on lands, rocks, tree trunks and walls of
houses, like dry vegetation.

Contacts: Suman Debnath, Ph-7687931008. E-Mail: sumandebnath98@gmail.com, Class: XII Page 20

BIOLOGY SUMAN DEBNATH (M.Sc in ZOOLOGY), B.Ed (Life Science), C.TET

11.Objective: To study homology and analogy with the help of preserved specimens, of
organs of animals

Apparatus and Materials Required:

Preserved specimens of different organs of animals / flash cards.

Theory: In animals, organs that are functionally dissimilar but anatomically, or structurally, similar are
called homologous organs. Different modes of life have created the differences, i.e, modified the organs to
enable them to survive. Analogous organs are those which are functionally similar but structurally
dissimilar.

Homologous Organs in Animals

Wings of birds, and forelimb of mammals/reptiles/ frog: All have the same bony elements
(Humerus, radius -ulna, carpals, metacarpals and phalanges), but perform different (flying in birds, for
holding or walking etc. in other) functions.
Analogous Organs in Animals

(i) Wings of dragonfly/cockroach/butterfly and of birds.

(ii) Mandible of cockroach and mandible (lower jaw) of a vertebrate.

Homologous Organs in Plants

Example of such homologous structure in plants is that of tendril
of Cucurbita and thorn of Bougainvillea.
Both these structures are similar, as they are stem modifications,
but they perform different functions.
The thorn protects the plant from grazing animals while the
tendril provides support to growing plant stem.

Analogous Organs in Plants

Modified underground stems and modified roots Modified stems
(rhizome, corm, tuber) are analogous to modified roots (carrot, radish)
as they perform similar function of storage of food but their origin is
different. Rhizome of ginger, potato tuber, Colocasia are stems and
beetroot, radish etc.pear.

Contacts: Suman Debnath, Ph-7687931008. E-Mail: sumandebnath98@gmail.com, Class: XII Page 21