STUDENT SUPPORT MATERIAL - CLASS 12

STUDENT SUPPORT MATERIAL - 2021-22

KENDRIYA VIDYALAYA SANGATHAN

AHMEDABAD REGION

SESSION 2021-22

SUBJECT – BIOLOGY (TERM I)
CLASS - XII

CHIEF PATRON
Dr Jaideep Das, Deputy Commissioner, KVS RO Ahmedabad

PATRON
Smt Shruti Bhargava , Assistant Commissioner, KVS RO Ahmedabad

CO-ORDINATOR

MRS MAMTA SINGH – PRINCIPAL KV 2 KRIBHCO

CONTENT DEVELOPMENT COMMITTEE

MR. GIRISH KUMAR – PGT BIOLOGY KV NO. 2 ARMY BHUJ
MRS. MINAKSHI SHARMA – PGT BIOLOGY KV ONGC SURAT

REVIEWED BY

MR. NIRANJAN RAM – PGT BIOLOGY KV 2 KRIBHCO SURAT

1

INDEX PAGE NO.

S.NO. TOPIC 3-7
8-34
Unit wise distribution of marks 35-64
1 & detailed syllabus 65-85
86-97
Chapter 2 98-110
2 Sexual Reproduction in Flowering Plants 111

Chapter 3
3 Human reproduction

Chapter 4
4 Reproductive Health

Chapter 5
5 Principles of Inheritance and Variations

Chapter 6
6 Molecular Basis of Inheritance

7 Useful links

2

BIOLOGY

(Code No. 044)
COURSE STRUCTURE
CLASS XII (2021 - 22)

Units EVALUATION SCHEME Marks
VI Theory 15
VII
Term – I
Units Reproduction: Chapter - 2, 3 and 4
VIII
Genetics and Evolution: Chapter – 5 and 6 20
IX
X Term - II Marks

Biology and Human Welfare: Chapter – 8 and 10 14

Biotechnology and its Applications: Chapter – 11 and 12 11

Ecology and Environment: Chapter – 13 and 15 10

Total Theory (Term – I and Term – II) 70
Practicals Term – I 15
Practicals Term – II 15
Total 100

TERM - I
Unit-VI Reproduction

Chapter-2: Sexual Reproduction in Flowering Plants

Flower structure; development of male and female gametophytes; pollination - types, agencies and
examples; outbreeding devices; pollen-pistil interaction; double fertilization; post fertilization events
- development of endosperm and embryo, development of seed and formationof fruit; special modes-
apomixis, parthenocarpy, polyembryony; Significance of seed dispersal and fruit formation.

Chapter-3: Human Reproduction

Male and female reproductive systems; microscopic anatomy of testis and ovary; gametogenesis
- spermatogenesis and oogenesis; menstrual cycle; fertilisation, embryo development upto blastocyst

formation, implantation; pregnancy and placenta formation (elementary idea); parturition
(elementary idea); lactation (elementary idea).

Chapter-4: Reproductive Health

Need for reproductive health and prevention of Sexually Transmitted Diseases (STDs); birth control -
need and methods, contraception and medical termination of pregnancy (MTP); amniocentesis;
infertility and assisted reproductive technologies - IVF, ZIFT, GIFT (elementary idea for general
awareness).

Unit-VII Genetics and Evolution

Chapter-5: Principles of Inheritance and Variation

Heredity and variation: Mendelian inheritance; deviations from Mendelism – incomplete dominance,
co-dominance, multiple alleles and inheritance of blood groups, pleiotropy; elementary idea of

3

polygenic inheritance; chromosome theory of inheritance; chromosomes and genes; Sex
determination - in human being, birds and honey bee; linkage and crossing over; sex linked
inheritance - haemophilia, colour blindness; Mendelian disorders in humans -thalassemia;
chromosomal disorders in humans; Down's syndrome, Turner's and Klinefelter's syndromes.

Chapter-6: Molecular Basis of Inheritance

Search for genetic material and DNA as genetic material; Structure of DNA and RNA; DNA packaging;
DNA replication; Central Dogma; transcription, genetic code, translation; gene expression and
regulation - lac operon; Genome, Human and rice genome projects; DNA fingerprinting.

TERM - II
Unit-VIII Biology and Human Welfare

Chapter-8: Human Health and Diseases

Pathogens; parasites causing human diseases (malaria, dengue, chikungunya, filariasis, ascariasis,
typhoid, pneumonia, common cold, amoebiasis, ring worm) and their control; Basic concepts of
immunology - vaccines; cancer, HIV and AIDS; Adolescence - drug and alcohol abuse.

Chapter-10: Microbes in Human Welfare

Microbes in food processing, industrial production, sewage treatment, energy generation andmicrobes as
bio-control agents and bio-fertilizers. Antibiotics; production and judicious use.

Unit-IX Biotechnology and its Applications
Chapter-11: Biotechnology - Principles and Processes

Genetic Engineering (Recombinant DNA Technology).

Chapter-12: Biotechnology and its Application

Application of biotechnology in health and agriculture: Human insulin and vaccine production, stem cell
technology, gene therapy; genetically modified organisms - Bt crops; transgenic animals; biosafety
issues, biopiracy and patents.

Unit-X Ecology and Environment
Chapter-13: Organisms and Populations

Organisms and environment: Habitat and niche, population and ecological adaptations; population
interactions - mutualism, competition, predation, parasitism; population attributes - growth, birth
rate and death rate, age distribution.

Chapter-15: Biodiversity and its Conservation

Biodiversity - Concept, patterns, importance; loss of biodiversity; biodiversity conservation; hotspots,
endangered organisms, extinction, Red Data Book, Sacred Groves, biosphere reserves, national parks,
wildlife, sanctuaries and Ramsar sites.

4

PRACTICALS

Max. Marks: 15 for each Term

Evaluation Scheme TERM - II MARKS
TERM - I
4
Part A Experiment No. – 1 Experiment No. - 3 3
One Major Experiment
3
One Minor Experiment Experiment No. - 2 Experiment No. – 4, 5 5

Part B

Spotting B.1, 2, 3, 4, 5 B.6, 7, 8
(3 Spots of 1 mark each)

Practical Record + Investigatory Project &Record + Viva Voce

Total 15
Practicals should be conducted alongside the concepts taught in theory classes.

A. LIST OF EXPERIMENTS

TERM - I:

1. Isolate DNA from available plant material such as spinach, green pea seeds, papaya, etc.
2. Prepare a temporary mount to observe pollen germination.

TERM - II:

3. Prepare a temporary mount of onion root tip to study mitosis.
4. Collect water from two different water bodies around you and study them for

pH, clarity andpresence of any living organism
5. Collect and study soil from at least two different sites and study them for

texture, moisturecontent, pH and water holding capacity. Correlate with the
kinds of plants found in them.

B. Study/observation of the following

(Spotting)

TERM - I:

B.1 Flowers adapted to pollination by different agencies (wind, insects, birds).
B.2 Identification of stages of gamete development, i.e., T.S. of testis and T.S. of ovary

throughpermanent slides (from grasshopper/mice).
B.3 Meiosis in onion bud cell or grasshopper testis through permanent slides.
B.4 T.S. of blastula through permanent slides (Mammalian).
B.5 Prepared pedigree charts of any one of the genetic traits such as rolling of tongue,

bloodgroups, ear lobes, widow's peak and colourblindness.

TERM – II:

B.6 Common disease - causing organisms like Ascaris, Entamoeba, Plasmodium, any fungus
causing ringworm through permanent slides, models or virtual images. Comment on
symptoms of diseases that they cause.

5

B.7 Two plants and two animals (models/virtual images) found in xeric conditions.
Comment upon their morphological adaptations.

B.8 Two plants and two animals (models/virtual images) found in aquatic conditions.
Comment upon their morphological adaptations.

Practical Examination for Visually Impaired Students of Classes XI and
XII

Evaluation Scheme

Max. Marks: 15 for each Term

Topic Marks
Identification/Familiarity with the apparatus 5
Written test (Based on given/prescribed practicals) 5

Practical Records and Viva 5
Total 15

General Guidelines

 The practical examination will be of one-hour duration.
 The written examination in practicals for these students will be conducted at the

time ofpractical examination of all other students.
 The written test will be of 30 minutes duration.
 The question paper given to the students should be legibly typed. It should contain a

total of 8 practical skill based very short answer type questions. A student would be
required to answer any 5 questions.
 A writer may be allowed to such students as per CBSE examination rules.
 All questions included in the question paper should be related to the listed
practicals. Every question should require about two minutes to be answered.
 These students are also required to maintain a practical file. A student is expected to
record the listed experiments Term -wise as per the specific instructions for each
subject. These practicals should be duly checked and signed by the internal
examiner.
 The format of writing any experiment in the practical file should include aim, apparatus

required, simple theory, procedure, related practical skills, precautions etc.

 Questions may be generated jointly by the external/internal examiners and
used forassessment.

 The viva questions may include questions based on basic theory/principle/concept,
apparatus/materials/chemicals required, procedure, precautions, sources of error
etc.

6

Practicals should be conducted alongside the concepts taught in theory classes.
A. Items for Identification/ familiarity with the apparatus for assessment in practicals

(Allexperiments)
TERM -I:
 Beaker, flask, petri plates, test tubes, aluminium foil, paint brush, bunsen
burner/spiritlamp/water bath.
 Starch solution, iodine, ice cubes.
 Developmental stages of frog highlighting morula and blastula.
TERM -II:
 Soil from different sites- sandy, clayey, loamy; Small potted plants, Cactus/Opuntia
(model),Large flowers, Maize inflorescence.
 Model of Ascaris
TERM -I:
1. Study of flowers adapted to pollination by different agencies (wind, insects).
2. Identification of T.S of morula or blastula of frog (model).
3. Preparation of pedigree charts of genetic traits such as rolling of tongue, colour blindness.
TERM -II:
4. Study of the soil obtained from at least two different sites for their texture.
5. Identify common disease-causing organisms like Ascaris (Model) and learn
somecommon symptoms of the disease that they cause.
6. Comment upon the morphological adaptations of plants found in xerophytic conditions.

Note: The above practicals may be carried out in an experiential manner rather than recording
observations.

Prescribed Books:

1. Biology, Class-XII, Published by NCERT
2. Other related books and manuals brought out by NCERT (including multimedia)
3. Biology Supplementary Material (Revised). Available on CBSE website.

7

CHAPTER 2 : SEXUAL REPRODUCTION IN FLOWERING PLANTS
KEY POINTS

S. No Term Explanation

1 Microsporogenesis Formation of microspores from a PMC through meiosis

2 Megasporogenesis Formation of megaspores from the megaspore mother cell

3 Monosporic development Embryo sac formation from a single megaspore

4 Pollination Transfer of pollen grains from anther to the stigma of a pistil
5 Autogamy Transfer of pollen grains from the anther to the

6 Geitonogamy stigma of the same flower
7 Xenogamy Transfer of pollen grains from the anther to the stigma of
8 Artificial hybridization another flower of the same plant
Transfer of pollen grains from anther to the stigma of a
different plant

Crossing different species to combine desirable

characters to produce superior varieties

9 Emasculation Removal of anthers from flower bud before the anther dehisces

10 Bagging Covering emasculated flowers with a bag to prevent
contamination of its stigma with unwanted pollen

11 Syngamy Fusion of male and female gametes

12 Triple fusion Fusion of three haploid nuclei

13 Double Fertilization Two types of fusions syngamy and triple fusion that takes place
in an embryo sac

14 Post fertilization events Events of endosperm, embryo development, maturation of

ovule into seed, ovary into fruit

Free –nuclear endosperm The stage of endosperm development wherein PEN undergoes
15 successive nuclear divisions to give rise to free nuclei

16 Dormancy of seed Embryo enter a state of inactivity (Resting period of seed)

17 False fruit Thalamus contributes to fruit formation
18 True fruit Fruits develop from the ovary
19 Parthenocarpic fruits Fruits develop without fertilization

20 Apomixis Production of seeds without fertilization, in grasses

21 Polyembryony More than one embryo in a seed

22 Filament Long slender stalk of stamen

23 Anther Bilobed structure of stamen

24 Dithecous Two theca in each lobe of anther

25 Tapetum Innermost wall layer of microsporangia

26 Sporogenous tissue Compactly arranged homogenous cells in the
centre of microsporangia
27 Microspore tetrad
28 Pollen grains Cluster of four microspores
Male gametophyte

8

29 Exine Hard outer layer of pollen grain
30 Sporopollenin Most resistant organic material of exine
31 Germ pore Apertures in pollen grain
32 Intine Inner wall of the pollen grain
33 Generative cell Cell floats in the cytoplasm of vegetative cell
34 Monocarpellary Single pistil
35 Multicarpellary More than one pistil
36 Syncarpous Fused pistils
37 Apocarpous Free pistils
38 Stigma
39 Style Landing platform of pollen grains
40 Ovary Elongated slender part beneath the stigma
41 Ovule
Basal bulged part of pistil
42 Funicle Megasporangium
43 Hilum
44 Integuments Stalk of ovule
45 Micropyle Region where the body of the ovule fuses with funicle
46 Chalaza
47 Embryo sac Protective envelopes of ovule
48 Egg apparatus Small opening in the ovule

49 Antipodals Basal part of the ovule
Female gametophyte
50 Cleistogamous flower Three cells at the micropylar end with two synergids and one egg
cell
51 Zygote Three cells at the chalazal end

52 Primary endosperm cell Flowers that do not open at all

53 Embryogeny Diploid cell resulting out of fertilization
54 Epicotyl
55 Hypocotyl Central cell after triple fusion becomes PEC
56 Scutellum
Embryo development
57 Coleorrhiza Portion of embryonal axis above the level of cotyledons
58 Coleoptile
Portion of embrgonic axis below the level of cotyledons
59 Non-albuminous seed or Cotyledon of grass family situated towards one side of embryonal
ex- albuminous axis
Undifferentiated sheath that encloses radical and root cap
60 Albuminous
Hollow foliar structure that encloses a shoot apex and a few leaf
61 Perisperm primordial
62 Pericarp No residual endosperm as it is completely consumed during
embryo development
Retain a part of endosperm as it is not completely used up during
embryo development
Residual persistent nucellus
Wall of the fruit

9

Mind Map
10

SEXUAL REPRODUCTION IN FLOWERING PLANTS
FLOWER

 Site of sexual Reproduction
 Male and female reproductive organs are borne on flower
PARTS OF FLOWER
 Four whorls – calyx (sepals), corolla (petals), androecium (Male

reproductive organ), gynoecium (Female reproductive organs)
 Function of calyx: protects the bud.
 Function of corolla: attracts insects by its colour
Male Reproductive Organ/Adroecium
 Androecium consists of Stamens.
 Stamen consists of anther.
 Anther- bilobed 4 Microsporagia.

Refer fig. 2.1 of NCERT (L.S. OF A FLOWER WITH DIFFERENT PARTS)

MICROSPOROGENESIS
 The process of formation of microspores from pollen mother cell through
meiosis is called microsprogenesis.
 Tapetum: Inner most layer of wall of microsporangium. Cells have dense
cytoplasm. Generally, have more than one nucleus. Nourishes the
developing pollen grains.

11

Microspore mother cell (2n)

↓ Meiosis Microspore (n)
↓

Pollen grains (n)

 Pollen Grains have 2 outer walls

i.Exine

ii.Intine Exine is mass of spropollenin.(Hardest natural substance).
Intine is made of cellulose and pectin.
 Mature pollen grains have two cells– large vegetative cell & small generative
 cell.
 Generative cell forms two male gametes by mitotic division.
Pollen grains (Refer fig 2.7 of text book) shed in 2-celled / 3 celled stage)



See Fig 2.5 a and b page 23

Gynoecium / Carpel (the female reproductive organ)

 Each carpel consists of ovary, style and stigma.
 Ovules are attached to ovary by placenta.
 Funicle– stalk of ovule.

12

 Hilum, a region where funicle is attached.
 Micropyle, a pore for entry of pollen tube & to imbibe water. (Structure

of anatropous ovule).
 Megasporangium

13

Megasporogenesis:

Megaspore mother cell (2n)
Meiosis

↓

4 Megaspores (n)
(3 megaspores degenerate, 1 remains functional)

↓
Funtional Megaspore (n) (Divides 3times by mitosis)

↓
8 Nucleated Embryo Sac formed

↓ ↓ ↓

2 polar nuclei at 3 cells at chalazal end 3 cells group at micropylar end -
center(n each ) called antipodals(n) the egg cell(n) & 2 synergids(n)

POLLINATION– Transfer of pollen from anther to stigma. Agents of
pollination –air, water, insect, bat, bird, man.
Double Fertilisation

 Pollen grains geminate on stigma & pollen tube grows through style.

 Pollen tube reaches micropyle & releases two male gametes into
embryo-sac. Fertilisation is the process of fusion of male& female
gametes (n+n) to form a diploid (2n) zygote. Syngamy: Fusion of one
male gamete (n) with egg (n) ---Zygote (2n) produced
First Fusion- Fusion of two Polar Nuclei (n+n=2n)

Second fusion- Male Gamete (n) Fuses with the fusion product of the two
polar nuclei (2n)

Third Fusion- Fusion of male gamete with egg cell.

 Double fertilzation

i.Fusion of male gamete with egg – First fertilization (SYNGAMY)

ii.Second fertilization- Fusion of fusion product of polar nuclei with male
gamete. (TRIPLE FUSION)
Refer fig 2.13 in NCERT

Post-fertilisation changes:

Stages of embryo development after fertilization:

1. Zygote divides by mitosis into suspensor & embryo cells

2. Suspensor cell forms a globular basal cell which remains embedded in the
endosperm & a multicellular suspensor bearing the embryo

14

3. Globular embryo becomes heart-shaped & then mature embryo with radicle,
plumule & cotyledons

 Primary endosperm nucleus– divides repeatedly to form endosperm, food
for the embryo.

 Mature ovary becomes fruit.
 Mature ovule becomes seed.
 True Fruit develops only from the ovary, e.g. mango, tomato

False Fruit develops from parts of the flower other than the ovary e.g.
apple, strawberry

Seeds are of two types
i.Albuminous (with Endosperm)
ii.Non albuminous (without Endosperm)

Special mechanism of reproduction:-
i.Apomixis- Production of seeds without fertilisation e.g.species of Astereceae
and grasses.

(ii) Polyembryony- Occurrence of more than one embryo in a seed
e.g.Orange.
Outbreeding devices:
 Continued self-pollination result in inbreeding depression.

15

 Flowering plants have developed many devices to discourage
self-pollination & encourage cross-pollination such as-

- Bearing unisexual flowers (Unisexuality)

-Anther & stigma mature at different times Dichogamy

-Anther & stigma placed at different positions Heterostyly

-Genetic mechanism by which pollen grains of a flower do not
germinate on the stigma of the same flower Self-incompatibility

Artificial Hybridisation-

Cross-pollination performed by man for crop
iprovement. Achieved by-
i.Emasculation i.e. removal of anthers from the flower bud of a bisexual flower
before the anther dehisces using a pair of forceps and
ii.Bagging i.e. covering the emasculated flowers with a bag of suitable size to
protect them from contamination with unwanted pollen.

If flower is unisexual, emasculation is not needed.

Flower bud bagged & when the stigma becomes receptive, pollination is
done using desired pollen & the flower is rebagged.

Pollen –pistil Interaction:

i.All the events from pollen deposition on the stigma until the entry of
the pollen tube into the ovule are together called pollen-pistil
interaction.

ii.It is a dynamic process involving pollen recognition by stigma/pistil for
compatible pollen by accepting them and if incompatible rejecting
them.

PRACTICE QUESTIONS

1. A bilobed, dithecous anther has 100 microspore mother cells per
microsporangium. How many male gametophytes this anther can produce?

a. 200
b. 400
c. 500
d. 600

16

2. An anther with malfunctioning tapetum often fails to produce viable male
gametophytes. Why?

a. A malfunctioning tapetum can’t provide nutrition to developing pollens
b. A malfunctioning tapetum can’t provide proper temperature to pollens
c. A malfunctioning tapetum can’t provide necessary hormones
d. None of the above

3. What are the component cells of the egg apparatus in an embryo sac?

a. An egg cell and two antipodal cells
b. Three antipodal cells
c. An egg cell and two synergids

d. Two synergids only

4. During polyembryony, if one embryo is formed from synergids and the other
from nucellus, state the one that is haploid and the one that is diploid.

a. From synergids – n, from nucellus – 2n
b. From synergids – n, from nucellus – n
c. From synergids – 2n, from nucellus – 2n
d. From synergids – 2n, from nucellus – n

5. Apple referred to as a false fruit because

a. It’s developed from ovary only
b. It’s developed without fertilization
c. It develops from thalamus
d. None of above

6. The pollinating agent of an inflorescence of small dull colored flowers
with well exposed stamens and large feathery stigma is

a. Wind
b. Insects
c. Ants
d. Water

7. What is the name of the protective substance present on outer pollen
covering to tide over adverse conditions?

a. Exine
b. Intine
c. Mucilage
d. Sporopollenin

8. Which feature is most prominent in moth pollinated flower?

a. Presence of large, colored petals
b. Presence of fragrance and nectar
c. Presence of fragrance but no nectar
d. A and b both

9. Which part of coconut is similar to mango pulp?

a. The coconut water
b. Fibrous mesocarp coir
c. The white soft part
d. No part is similar to mango pulp

17

10. Which is a triploid tissue in a fertilized ovule?

a. Zygote
b. Nucellus
c. Endosperm
d. Integuments

11. In a flower what develops into a microspore mother cell?

a. Synergid
b. Tapetal cell
c. Cell of endothecium
d. Sporogenous cell

12. In the given figure of embryo of maize 2 is

a. Scutellum
b. Epicotyl
c. Hypocotyl
d. Aleuron layer

13. Which type of pollination occurs in self-incompatible plants?

a. Cross pollination
b. Self-pollination
c. No pollination
d. Multiple pollination

14. Which cells are found in pollen grain which sheds at 3 celled stage?

a. 2 generative cells and 1 vegetative cell
b. 2 vegetative cells and 1 generative cell
c. 2 vegetative cells and 1 male nucleus
d. 2 male nuclei and 1 vegetative cell

15. Perisperm is

a. Remnant of nucellus
b. Degenerate synergids
c. Degenerated secondary nucellus

d. Peripheral part of endosperm

16. Which of the following condition will lead to formation of parthenocarpic fruit?

a. Fruit without seed after pollination
b. Fruit with seeds after fertilisation
c. Fruit with viable seeds without fertilisation
d. Fruit with viable seeds after fertilisation

17. If an endosperm cell of an angiosperm has 24 chromosomes then what will be
the number of chromosomes in megaspore mother cell

a. 8
b. 14
c. 16
d. 38

18

18. Sporopollenin is secreted by nucleus

a. Cytoplasm of pollen grains
b. Cytoplasm of pollen mother cell
c. Cytoplasm of endothecium
d. Cytoplasm of tapetum

19. In anther pollen sac is equivalent to

a. Microsporangium of Pinus
b. Microsporophyll of Pinus
c. Male cone
d. Female cone

20. Double fertilization is

a. Fusion of male and female gamete
b. Fusion of one male gamete with egg cell and one male gamete with secondary
c. Fusion of eggs and pollen nuclei of two pollens
d. Fusion of one male gamete with edd and another with synergids

21. In the process of microsporogenesis , meiosis occurs in

a. Microspore tetrad
b. Microspore mother cell
c. Endothecium cell
d. Pollen grain

22. Wind pollination is common in_______

a. Grasses
b. Legumes
c. Orchids
d. Lotus

23. In angiosperms, functional megaspore develops into

a. Endosperm
b. Embryo sac
c. Pollen chamber
d. Ovule

24. In which of the following case autogamy will occur?

a. Cleistogamy
b. Xenogamy
c. Geitonogamy
d. Chasmogamy

25. Filiform apparatus is a characterstic feature of

a. Zygote
b. Egg
c. Suspensor
d. Synergid

Q. ANS Q. NO. ANS Q. NO. ANS Q. NO. ANS Q. NO. ANS

NO.

1 B 2 a3 c4 a5 c

6 a 7 d 8 b 9 b 10 c

11 d 12 a 13 a 14 d 15 a

16 a 17 c 18 d 19 a 20 b

21 b 22 a 23 b 24 a 25 d

19

ASSERTION AND REASON TYPE QUESTIONS

Options for the questions

A. Both assertion and the reason are true and the reason is a correct explanation
of the assertion
B. Both the assertion and reason are true but the reason is not a correct
explanation of the assertion
C. Assertion is true but the reason is false
D. Both assertion and reason are false

1.Assertion: Angiospermic flowers perform the function of sexual reproduction.

Reason: The male and female reproductive structures are found in the flowers.
2. Assertion: Endosperm is a nutritive tissue and it is triploid.

Reason: Endosperm is formed by fusion of secondary nucleus to second male
gamete. It is used by developing embryo.
3. Assertion: The two cotyledons in seed are embryonic leaves.

Reason: The embryo contains radicle and plumule.
4. Assertion: The embryo which is capable to germinate should have well-
developed radical, plumule and one or two cotyledons.

Reason: In the Orobanchaceae and Orchidaceae the embryo never differentiates
a true radicle, plumule and cotyledons, but can germinate.
5. Assertion: Chasmogamous flowers require pollinating agents.
Reason: Cleistogamous flowers do not expose their sex organs.

6. Assertion: Nuclear endosperm is formed by subsequent nuclear division
without wall formation.

Reason: Coconut is an example of such endosperm, where the endosperm
remains nuclear throughout the development of the fruit.
7. Assertion: The embryo sac is 7- celled and 7- nucleated structure.
Reason: All cells are haploid.

8. Assertion: Megaspore mother cell undergoes meiotic division.
Reason: All four megaspores form female gametophyte.

9. Assertion: Tapetum helps in the liberation of microspores from tetrad.
Reason: Tapetum shows callase activity.

10. Assertion: Xenogamy is pollination between two flowers on different plants.
Reason: Autogamy is pollination between two flowers on the same plant.

11. Assertion: Maize is an albuminous seed.

Reason: The endosperm in maize is completely consumed by its developing
embryo.

20

12. Assertion: The process of parthenogenesis is a type of apomixis where seeds
are developed from unfertilized female gamete.

Reason: Parthenogenesis always occurs by the application of chemicals.
13. Assertion: Most of the insect pollinated flowers are large, colorful, fragrant and
having nectar.

Reason: Animals are attracted towards bright colors or fragrance.
14. Assertion: Pollen mother cells (PMCs) are the first male gametophytic cells.

Reason: Each PMC gives rise to two pollens.
15. Assertion: Chasmogamous flowers require pollinating agents.

Reason: Cleistogamous flowers do not expose their sex organs.
16. Assertion: Geitonogamy is genetically similar to autogamy.

Reason: The pollen grains come from same plant.
17. Assertion: A typical microsporangium of angiosperms is generally surrounded
by four wall layers.

Reason: The outer three wall layers perform the function of protection and help in
dehiscence of anther to release the pollen.

18. Assertion: Exine of a pollen grain is made up of sporopollenins which are
resistant to high temperatures, strong acids or alkali as well as enzymatic
degradation.

Reason: Sporopollenin are absent in the region of germ pores.
19. Assertion: Although geitonogamy is functionally cross-pollination involving a
pollinating agent, genetically it is similar to autogamy since the pollen grains come
from the same parent.

Reason: In geitonogamy, pollen grains from the anthers of one flower are
transferred to the stigma of another flower borne on the same plant.
20. Assertion: Hydrophily is a major mode of pollination in most of the aquatic
plants in angiosperms.

Reason: Almost all the aquatic dicot and monocot plants require water for the
transport of male gametes and for fertilisation.

ANSWER KEY

1–A 2–A 3–B 4–B 5–B
6 – C 7 – D 8 - C 9 – A 10 – C
11 - C 12 - C 13 - A 14 - D 15 -B
16 - A 17 - B 18 - B 19 - A 20 - D

21

CASE BASED QUESTIONS

1. Read the following and answer any four questions:

In angiosperm, the seed is the final product of sexual reproduction. It is
described as a fertilized ovule. The seeds are formed inside the fruit. The seed
consists of a seed coat, cotyledon, and the embryo axis. A mature seed is
usually non - albuminous or albuminous. Integument of ovules hardens as
tough protective seed coat. Sometimes due to reduced water content, the
general metabolic activity of the seed slows down and the seed enters a state
of inactivity. In the mature plant, the fruit develops from the ovary they are
called true fruit. The fruit is the result of fertilization. There are a few species
in which fruit develop without fertilization banana is such an example
i.Which of the following have non-albuminous seed?

a. Sunflower
b. Groundnut
c. Maize
d. Barley

ii.The entry of oxygen and water in the seed during germination:

a. micropyle
b. chalazal
c. epicotyl
d. hypocotyls

c. The embryo enters the state of inactivity called:
a. Pericarp
b. Dormancy
c. Apomixes
d. none of these

iv. The wall of the ovary develops into the wall of fruit called:
a. scutellum
b. pericarp
c. plumule
d. radicle

v.The figure given below represent

a. true fruit
b. parthenocarpic fruit
c. false fruit of apple
d. false fruit of strawberry

22

2. Read the following and answer any four questions:

The gynoecium represents the female reproductive part of the flower. The
gynoecium may consist of a single or more than one pistil. They may be fused
or maybe free. The placenta is located inside the ovarian cavity.
Megasporangium (ovule) consists of a small structure attached to the placenta
by a stalk called a funicle. The body of the ovules fuses with a funicle in the
region called hilum. The nucleus is located in the embryo sac. The process of
formation o, megaspore from the megaspore mother cell is called
megasporogenesis. Meiosis results in the formation of four megaspores.
i.Gynoecium with a single pistil is known as:

a. multicarpellary
b. monocarpellary
c. syncarpous
d. apocarpous

ii. Which of the following is not a part of pistil?
a. Stigma
b. Style
c. Ovary
d. Stamen

iii.The protective covering of the ovule is called:

a. Integument
b. Micropyle
c. Chalaza
d. hilum

iv.Which of the following have only one ovule in the ovary?

a. Papaya
b. Watermelon
c. Mango
d. Orchids

v. Which of the following shows the mature embryonic sac

a. only (I)
b. Both (I) and (II)
c. only (III)
d. None of these

23

3. Read the following and answer the four questions:
During fertilization in the plant, the pollen tube releases the two male
gametes into the cytoplasm of synergid. One moves toward the egg and fuse
to complete syngamy another fuse with the central cell. It involves g haploid
nuclei it is termed as triple fusion. The central cell develops into ends sperm
and the zygote develops into an embryo. The embryo develops at micropyle
ends. Zygote gives rise to proembryo and subsequently to a globular, heart-
shaped mature embryo. The embryo of monocotyledon possesses only one
cotyledon.
i. At the lower end, the embryonal axis has the radical and root cap enclosed in
an undifferentiated sheath called

a. Coleoptile
b. Coleorhiza
c. Integument
d. All of these

ii.The male gamete which moves towards the two polar nuclei located in the cell
and fuse with them to produce
a. Zygote
b. Embryo
c. Primary endosperm nucleus
d. None of these

iii.The cylindrical portion below the level of cotyle is
a. HypocotyL

b. Root cap

c. Plumule

d. Epicotyl
iv.The grass family cotyledon is called
a. Epicotyl

b. Scutellum
c. Plumule
d. Radical

v. Which of the following statement is correct for the figure given below?

24

a. (A) ertilized embryo sac

b. (D) stage in embryo development in dicot

c. (B) zygote

d. (A) is the globular embryo, (D) is the mature embryo

4. In major approaches of crop improvement program as in crossing
experiments, it’s important to make sure that only desired pollens are used for
pollination and stigma is protected from unwanted pollens. That’s why in bisexual
flowers the removal of removal of anthers from flower bud before maturity is
necessary. This emasculated flower has to be covered with bags. When the
stigma of bagged flower becomes receptive, desired mature pollens are dusted on
stigma and flowers are rebagged. In unisexual flowers there is no need of
emasculation.

i.In a hybridization experiment with dioecious plant, which of the following step
is not relevant?
a. Bagging
b. Dusting of pollens
c. Emasculation

d. Pollen collection

ii. Correct sequence of artificial hybridization experiment is
a. Bagging – Emasculation – Rebagging – Cross pollination
b. Emasculation – Bagging - Cross pollination – Rebagging
c. Rebagging – Bagging – Cross pollination - Emasculation
d. Cross pollination – Emasculation – Bagging – Rebagging

iii.In hybridization experiment bagging is done to
a. Prevent unwanted self pollination
b. Prevent unwanted cross pollination
c. Prevent contamination of germs
d. None of above

iv.Emasculation is done to
a. Prevent unwanted self pollination
b. Prevent unwanted cross pollination

25

c. Prevent temperature fluctuation
d. Prevent entry of insects

v.Assertion : If a female plant is selected for breeding experiment then in female
unisexual plant there is no need of emasculation.

Reason : Emasculation is removal of immature anthers.
a. Both assertion and the reason are true and the reason is a
correct explanation of the assertion
b. Both the assertion and reason are true but the reason is not a correct
explanation of the assertion
c. Assertion is true but the reason is false
d. Both assertion and reason are false

Read the given paragraph and answer the following:

Cross pollination is the process of transfer of pollens from anther of one flower to
stigma of another genetically different flower. This can be done by external
agency which can be biotic( as insects) or abiotic (as wind and water). In figure
an insect pollinated flower carpel is shown:

i. What can be the possible reason behind non germination of pollen Z in the given
figure
a. X and Y reached stigma before Z so they prevent pollen tube
germination of Z.
b. Z was carried by wind and X and Y by insects
c. Z lacks proper protrusions to attach to the stigma
d. Z has arrived from a flower of incompatible species.

ii.Pollination by insects is called as

a. Anemophily
b. Entomophily
c. Hydrophily
d. Chiropterophily

. Characteristics of some flowers are given below:
 Stamens are hanging out to expose anthers to wind
 Pollens are tiny and light weight
 Flower has bright and colorful petals
 Flower has fragrance

How many characters out of above are of insect pollinated flowers
a. 1
b. 2
c. 3
d. 4

26

iv. Which of the following statement describes the function of a pollen tube
a. It acts as a conduit to transport male gametes from anther to ovule
b. It acts as a conduit to transport male gametes from stigma to
ovule
c. It provides necessary nourishment to pollens
d. It digests the tissues of stigma and ovule.

v.Pollen tube germinates through

a. Exine
b. Intine
c. Germ pores
d. None of above

1 (i)- (b) 1 (ii)- (a) 1 (iii)- (b) 1 (iv)- (b) 1 (v)- (d)
2 (i)- (b) 2 (ii)- (d) 2 (iii)- (a) 2 (iv)- (b) 2 (v)- (a)
3 (i)- (b) 3 (ii)- (c) 3 (iii)- (a) 3 (iv)- (b) 3 (v)- (d)
4 (i)- (c) 4 (ii)- (b) 4 (iii)- (b) 4 (iv)- (a) 4 (v)- (b)
5 (i)- (d) 5 (ii)- (b) 5 (iii)- (a) 5 (iv)- (b) 5 (v)- (c)

CHECK YOUR GRASP

Time: 90 minutes Maximum Marks: 35

General Instructions:

i.All questions are compulsory.

ii.The question paper has three sections: Section A- MCQ, Section B -Assertion –
Reason type questions and Section C- Case study base questions. There are 27
questions in the question paper.

iii.Section–A has 15 questions of 1 mark each and. Section–B has 10 questions of
1 mark each and Section–C has 2 questions of 5 marks each.

iv.There is no overall choice.

SECTION A

Questions Mark

s

1. Name the type of flower which favors cross pollination 1

a. Chasmogamous (b) Cleistogamous (c) Both of above (d) None of

above

2. Embryo sac is related to ovule similarly ……………….is related to anther. 1

a. Androecium (b) Pollen grain (c) Stamen (d) Filament 1

3. Which regions of pistil form fruits and seeds?
a. Ovule and ovary (b) Endosperm and ovule
(c) Ovary and ovule (d) Nucellus and ovary

27

4. Choose the correct statement out of the following 1

(a) Cleistogamous flowers can perform both autogamy and 1
geitonogamy
(b) Chasmogamous flowers always perform autogamy 1
(c) Cleistogamous flowers perform autogamy always 1
(d) Chasmogamous flowers always perform geitonogamy 1
1
5. Which situation out of the following will prevent both autogamy and
geitonogamy

a. Monoecious plant bearing unisexual flowers.

b. Monoecious plant bearing bisexual flowers.

c. Dioecious plant bearing only male flowers or female flowers.

d. Dioecious plant with bisexual flowers.
6. How many nuclei are involved in double fertilization in angiosperms?

a. 2 (b) 4 (c) 5 (d) 3

7. The phenomena in which ovary develops into fruit without fertilisation
is

a. Apomixis (b) Parthenocarpy

(c) Sexual reproduction (d) Asexual reproduction

8. Why does endosperm development precedes embryo development?

a. To provide protective covering to developing embryo
b. To secrete enzymes for metabolic reactions

c. To provide nourishment for germination of seed
d. To provide nourishment to developing embryo

9. Following are the figures of a typical dicot and monocot plant, in
these two the true homologous structures are

a. Coleorhiza and Coleoptile (c) Coleoptile and Scutellum 1
1
b. Scutellum and Cotyledon (d) Hypocotyl and radicle
10. One megaspore mother cell forms 28

a. One functional megaspore (c) Two functional megaspores

b. Three functional megaspores (d) Four functional megaspores
11. In a fertilized embryo sac, the haploid, diploid and triploid structures

are
a. Synergids and antipodals (c) Synergids, zygote and PEN

b. Antipodal, synergid and PEN (d) Synergid, polar nuclei and

zygote

12 Which of the following layers is not a part of wall layer of 1
1
microsporangium? 1
1
a. Integument (c) Tapetum 1

(b) Endothecium (d) Middle layers 1
13 Pollen grain represents
(c) Male gametophyte 1
a. Female gametophyte (d) Anther
b. Sporophyte 29

14 Sporopollenin is found in

a. Exine (c) Middle

layer

b. Intine (d) Endothecium
15. Megasporophyll is called as

a. Stamen (c) Ovary

b. Carpel (d) Stigma

SECTION B
16 Assertion: Continuous self-pollination generation after generation
. results in pure line formation.

Reason: by continuous self-pollination plants becomes

pure or homozygous for its characters.

a. Both assertion and reason are true, and the reason is the
correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is not the
correct explanation of the assertion.
c. Assertion is true but reason is false.

d. Both assertion and reason are false
17. Assertion: Apple is a false fruit.

Reason: The thalamus contributes to the formation of apple
fruit along with ovary.

a. Both assertion and reason are true, and the reason
is the correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is
not the correct explanation of the assertion.
c. Assertion is true but reason is false.
d. Both assertion and reason are false
18. Assertion: Ovule after fertilization forms the
fruit. Reason: The fruits contain diploid
endosperm.

a. a. Both assertion and reason are true, and the reason is
the correct explanation of the assertion.
b. b. Both assertion and reason are true, but the reason is not
the correct explanation of the assertion.
c. c. Assertion is true but reason is false.
d. d. Both assertion and reason are false

19. Assertion: Protandry is a condition in which anthers matures earlier 1
than stigma. 1
Reason: Cleistogamous flowers are bi-sexual and never open
1
a. a. Both assertion and reason are true, and the reason is the 1
correct explanation of the assertion. 1
b. b. Both assertion and reason are true, but the reason is not
the correct explanation of the assertion. 30
c. c. Assertion is true but reason is false.
d. d. Both assertion and reason are false
20. Assertion: Pollen grains can germinate on the stigma of any species

of plants.
Reason: Pollen grains represent the male gamete.

a. Both assertion and reason are true, and the reason is
the correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is
not the correct explanation of the assertion.
c. c. Assertion is true but reason is false.
d. d. Both assertion and reason are false
21 Assertion: The innermost layer of microsporangium is called as
tapetum.

e. Reason: Tapetum nourishes the developing pollen grain.

f. a. Both assertion and reason are true, and the reason is the
correct explanation of the assertion.

g. b. Both assertion and reason are true, but the reason is
not the correct explanation of the assertion.

h. c. Assertion is true but reason is false.

i. d. Both assertion and reason are false
22 Assertion: Fertilisation in flowers, produces fruits and seeds.

Reason: After fertilization the ovary develops into fruits and ovule
develops into seed.

a. Both assertion and reason are true, and the reason is the
correct explanation of the assertion.

b. Both assertion and reason are true, but the reason is not the
correct explanation of the assertion.

c. Assertion is true but reason is false.
d. Both assertion and reason are false
23 Assertion: Mustard, pea and bean are non-albuminous seeds.
Reason: The non - albuminous seeds retain a part of endosperm as
it’s not completely used up during embryo development.

a. Both assertion and reason are true, and the reason
is the correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is
not the correct explanation of the assertion.
c. Assertion is true but reason is false.
d. Both assertion and reason are false

Assertion: Cleistogamous flowers are able to produce seeds without
24 pollination.

Reason: Cleistogamous flowers have no chance of cross pollination
and they are truly autogamous.
a. Both assertion and reason are true, and the reason is the
correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is not the
correct explanation of the assertion.
c. Assertion is true but reason is false.
d. Both assertion and reason are false

Assertion: In anther abnormal pollens are produced if the tapetum
25 is not intact or not functioning properly.

Reason: Tapetum secretes nourishment for developing pollen
grains.

a. Both assertion and reason are true, and the reason is the
correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is not the
correct explanation of the assertion.
c. Assertion is true but reason is false.
d. Both assertion and reason are false

CASE BASED QUESTIONS

26. Read the following and answer the questions from 15(i) to 15(v) given

below:

Double Fertilisation 5

After pollen germination in flowering plants, the pollen tube penetrates
through the stigma and the tube grows through the style and reaches
the ovary. Once it reaches the ovary, the tube penetrates it and reaches
the micropyle of the ovule and enters into the embryo sac. Here, one of
the two male nuclei fuse with the nucleus of the egg cell to form a
zygote. This fusion of the male and female gametes is known as
syngamy. The other male gamete fuses with the two polar nuclei located
in the central cell to produce the triploid endosperm nucleus in a primary
endosperm cell (PEC). This fusion of three nuclei is termed as triple
fusion.
Since two types of fusions, syngamy and triple fusion take place in an
embryo sac, the phenomenon is termed double fertilization.
The zygote develops into an embryo while PEC develops into the
endosperm. The cells of endosperm tissue are filled with reserve food
materials and are used for the nutrition of the developing embryo.

i. Name the diploid cell of the embryo sac.
a. Egg cell
b. Ovary
c. Ovule
d. Central cell

31

ii. Double fertilization is a phenomenon found in
a. Bryophytes
b. Pteridophytes
c. Angiosperms
d. All of the above.

iii. At least how many pollen grains are required to fertilize 10 ovules in a
carpel?
a. 5
b. 10
c. 15
d. 20

iv. The ploidy of a zygote formed as a result of syngamy is
a. Diploid
b. Haploid
c. Triploid
d. None of the above.

v. Assertion: Endosperm development precedes embryo development.
Reason: Embryo develops at the micropylar end of the embryo sac where
the zygote is situated.
a. Both assertion and reason are true, and the reason is the
correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is not the
correct explanation of the assertion.
c. Assertion is true but reason is false.

d. Both assertion and reason are false 5

27. Read the following and answer any four questions from 16(i) to 16(v)
given below:
Pollinating agents

The pollen-pistil interaction begins with pollination, followed by pollen
adhesion to the stigma. After it adheres, it imbibes water and gets
hydrated which initiates pollen tube germination. There are different
agents of pollination like wind, insects, birds and water.
Anemophilous flowers are pollinated by the agency of wind. These flowers
are small and inconspicuous. The pollen grains are very light, non-sticky
and sometimes winged.
Entomophilic flowers are pollinated by insects.

These flowers are often attractive to look at with bright petals and are
fragrant to attract the insect visitors to them. They often have broad
stigmas or anthers to allow the insect to perch on it. Many of the insect-
pollinated flowers also secrete nectar which attracts bees, butterflies or
other similar insects to the flowers. The pollen grain surfaces of such
flowers produce mucilaginous secretion.Hydrophilic flowers are pollinated
by water. It is commonly found in algae,bryophytes, pteridophytes and
some angiosperms. The pollen grains may have a mucilaginous covering
to protect it from getting wet.

32

i. The pollinating agent of an inflorescence of small dull coloured flowers
with well exposed stamens and large feathery stigma is
a. Water
b. Wind
c. Insects
d. Birds.

ii. An example of biotic agent for pollination is
a. Air
b. Water
c. Honey bee
d. All of the above.

iii. The pollen grains in the flowers are generally sticky that help them to
a. stick on to the body of the insects
b. float on water
c. float in the air
d. fall on the ground safely.

iv. Which of the following statements seem to describe the water-
pollinated submerged plants?
a. The flowers do not produce nectar.
b. The flower petals are not brightly coloured.
c. The pollen grains have mucilaginous covering.
d. The female flowers have long stalk to reach the surface.

v. Assertion: The pollen grains are easily carried by the wind.
Reason: They are very light and sometimes winged.

a. Both assertion and reason are true, and the reason is the
correct explanation of the assertion.
b. Both assertion and reason are true, but the reason is not the
correct explanation of the assertion.
c. Assertion is true but reason is false.

d. Both assertion and reason are false.

33

MARKING SCHEME

Value Points Marks

SECTION – A 1
1
1 a. Chasmogamous flowers
2 b. Pollen grain 1
1
3 (c)Ovary and Ovule
4 (b) Chasmogamous flowers always perform autogamy 1
1
5 1
a. Dioecious plant bearing only male flowers or female flowers. 1
1
6
(c) 5 1

7 1
(b) Parthenocarpy
1
8
(d) Parthenocarpy 1

9 b. Scutellum and Cotyledon 1

10 (a) One functional megaspore 1

11 (b )Synergids, zygote and PEN 1
1
12 (a) Integument 1
1
13 (c)Male gametophyte 1
1
14 a. Exine 1
1
15. (b)Carpel SECTION – B 1
SECTION C 1
16 (a)
17 (c) 1
18 (d) 1
19 (b) 1
20 (d) 1
21 (b) 1
1
22 (a) 1
23 (c) 1
1
24 (a) 1

25 (a) 34

26.i D
26.ii C
26.iii B
26.iv A
26.v B*
27.i B
27.ii C
27.iii A
27.iv C
27.v A

CHAPTER 3 HUMAN REPRODUCTION

Basic Steps in Human Reproduction:

1. Gametogenesis
2. Insemination
3. Fertilization
4. Blastocyst development
5. Implantation
6. Embryo development
7. Parturition

 The male reproductive system has four main parts:

1. Testes
2. Accessory ducts
3. Glands
4. External Genitalia

Testes (singular Testis):

35

 Situated in the pelvic region outside the abdominal cavity within a pouch
called as scrotum.

 Scrotum is a small muscular sac that contains and protects the testes. It
is a part of the external malegenitalia and is located behind the penis.

 The testes are placed outside the abdominal cavity so as to
maintain a temperature that is 2-2.50C lower than the average
human body temperature.

 The lower temperature in testes is required for spermatogenesis as the
normal human body temperaturecan lead to mutation in the sperms.

 Each testis has about 250 compartments called as Testicular lobules
 Each lobule contains 1-3 highly coiled seminiferous tubules.
 Seminiferous tubules are the site for meiosis that leads to the formation of

spermatozoa.
 The inner lining of each seminiferous tubule consists of two types of cells:

Spermatogonia andSertoli cells.
 Spermatogonia are the immature male germ cells that undergo meiosis

that leads to formationof sperms. Each spermatogonium is diploid and
contains 46 chromosomes
 Sertoli cells provide nutrition to the spermatogonia
 Interstitial spaces: These are the regions outside the seminiferous tubules.
They contain small blood vessels, some immunocompetent cells and
interstitial cells or the Leydig cells.
 Leydig cells: These are the cells that synthesise and secrete testicular
hormones called androgens.
Accessory Ducts:
The accessory ducts transport the sperms from the testes to the urethra for their
release outside the body. There arefour accessory ducts in the male reproductive
system:

 Rete Testis
 Vasa efferentia
 Epididymis
 Vas deferens
 Ejaculatory duct

36

 Urethra

Acessory glands: They are:

 Seminal vesicles: They contribute approximately 60-75% of the
fluid in semen. The secretions are rich in proteins, enzymes, fructose,
vitamin C, phosphoryl choline and prostaglandins. The high fructose
content provides nutrient energy for the spermatozoa.

 Prostate Gland: It secretes a slightly alkaline milky fluid. This helps in
the survival of sperms in the acidic vaginal environment. The secretions
also improve the motility of the sperms

 Bulbourethral glands: The secretions of this gland lubricate the
penis and neutralise any residual acidity in the urethra.

Female Reproductive System
The human female reproductive system is specialised to support the process of

ametogenesis, ovulation, fertilisation, pregnancy, birth and child care. The parts of
the female reproductive system are:

1. A pair of ovaries

2. A pair of oviducts

3. Uterus

4. Cervix

5. Vagina

6. External genitalia

7. Mammary glands

Ovaries:

They are the primary female sex organs

 They produce the female gamete- ovum
 They also produce steroid hormones (Ovarian hormones)
 2-4cm in length and connected to the pelvic wall and uterus by ligaments
 Each ovary is covered by a thin epithelium enclosing an ovarian stroma
 Ovarian stroma- It is the matrix of the ovary and is divided into two zones:
 Peripheral cortex

37

 Inner medulla

Accessory Ducts:

They are the oviducts, uterus and the vagina
Oviduct (Fallopian Tube):
Each fallopian tube is 10-12 cm long
It extends from the periphery of each ovary to the uterus
Infundibulum: It is the funnel shaped part closer to the ovary
Fimbriae: They are the finger like projections at the edges of the infundibulum that
aid in collecting the ovum after ovulation

 Ampulla: It is the wider part of the oviduct after the infundibulum
 Isthmus: It is the last part of the oviduct. It has a narrow lumen and joins

the uterus
Uterus:

 It is also called as the womb
 It is shaped like an inverted pear
 It is attached to the pelvic wall by ligaments
 The uterus is the part where the embryo develops into the foetus.
 The uterus opens into the vagina through a narrow cervix
 Uterine wall has three layers of tissues: perimetrium, myometrium and the

endometrium
 Perimetrium: It is the thin external membranous layer
 Myometrium: It is the thick middle layer made up of smooth muscle. It

exhibits strong contractions during the delivery of the baby
 Endometrium: It is the inner glandular layer that lines the uterine

cavity. It undergoes periodic changes duringthe menstrual cycle.

38

Cervix:
 It is a narrow canal connecting the uterus to the vagina
 Cervical canal: The cavity of the cervix is called as the cervical canal.
 Birth canal: The cervical canal along with the vagina forms the birth canal

External Female Genitalia:
 They consist of: mons pubis, labia majora, labia minora, hymen and clitoris
 Mons pubis: It is a mass of fatty tissue covered by skin and hair
 Labia majora: They are fleshy folds of tissue that extend from the mons pubis

and cover the vaginal opening
 Labia minora: They are the paired folds of tissue under the labia majora
 Clitoris: It is a tiny finger-like projection that lies at the junction of the labia

minora above the urethral opening.
Mammary Glands:
 The presence of functional mammary glands is characteristic of all female mammals
 They are paired structures of breasts that contain glandular tissue and variable
amounts of fats.
 Glandular tissue in each mammary gland consists of 15-20 mammary lobes.
 The mammary lobes have clusters of cells called alveoli
 The cells of alveoli secrete milk.
 The milk is stored in the lumen or cavities of the alveoli
 The alveoli open into mammary tubules.
 The tubules of each lobe join to form a mammary duct.
 Several mammary ducts join to from a wider mammary ampulla
 The mammary ampulla is connected to a lactiferous duct through which milk is sucked
out.

39

Gametogenesis
Gametogenesis is the process by the primary male and female sex organs produce the
male and female gametes respectively.

Spermatogenesis: The process by which the immature male germ cells or spermatogonia
produce mature sperm cells in the testis
Oogenesis: The process by which the immature oogonia in the ovaries produce mature
ovum
Spermatogenesis:
The process of spermatogenesis begins at puberty and proceeds as follows:

 The spermatogonia multiply by mitosis to increase in number. They are
present in in the inner wall ofseminiferous tubules. Each spermatogonium
is diploid. Each spermatogonium contains 46 chromosomes.

 Some spermatogonia called as the primary spermatocytes periodically
undergo meiosis to form two equal, haploid cells called as the secondary
spermatocytes. They contain 23 chromosomes.

 The secondary spermatocytes produce four equal haploid cells after they
undergo second meiotic division.They are called as the spermatids. They
contain 23 chromosomes.

 The spermatids undergo spermiogenesis to form spermatozoa or sperms.
 The sperm heads are embedded in the Sertoli cells
 They are finally released from the seminiferous tubules by the process of

spermiation

Hormones affecting spermatogenesis:

 Gonadotropin releasing hormone (GnRH): It is a hormone secreted by the
hypothalamus. Its levels increase significantly at puberty. The increased levels
of GnRH stimulates the release of two gonadotropins – Follicle Stimulating
Hormone (FSH) and Luteinizing Hormone (LH), from the anterior pituitary.

 Follicle Stimulating Hormone (FSH): FSH acts on the Sertoli cells
and stimulates the release of some factors that help in the process of
spermatogenesis.

40

 Luteinizing Hormone (LH): LH acts on the Leydig cells and
stimulates the synthesis and secretion of androgens which in turn
stimulate the process of spermatogenesis

STRUCTURE OF SPERM

 It consists of a head, neck, middle piece and a tail
 Plasma membrane covers the whole body of the sperm
Oogenesis:
The process of formation of a mature female gamete is oogenesis and it is
initiated during the embryonic development stage. During this stage a couple of
million gamete mother cells or oogonia are formed in the fetal ovary. No more
oogonia are formed and added after birth.
 aTrhreesotoegdoantiathfoerm primary oocytes. The oogonia start the process of meiosis and get
stage of Prophase I. These cells originating from the oogonia that are
arrested at the prophase I are called as primary oocytes.
 Each primary oocyte gets surrounded by a layer of granulosa cells and is
now called as the primary follicle.
 A large number of primary follicles get degenerated between birth and
puberty. At puberty, therefore, there are only about 60,000-80,000
primary follicles in the ovary.
 These remaining primary follicles get surrounded by more layers of
granulosa cells as well as a new theca. They now form the secondary
follicle.

 The secondary follicle then gives rise to the tertiary follicle. The tertiary
follicle is characterised by the presence of a fluid filled cavity called as
antrum. The theca is organised into two layers-inner theca interna and the
outer theca externa. The primary oocyte grows in size and completes the

41

first meiotic division. It is an unequal division forming a large secondary
oocyte and a tiny first polar body.
 Secondary oocyte retains much of the nutrient rich cytoplasm.
 The tertiary follicle changes into the mature Graafian follicle.
 The secondary oocyte forms a new layer called as the zona pellucida around it.
 The Graafian follicle now ruptures to release the secondary oocyte (ovum)
from the ovary by the process of ovulation

42

Menstrual Cycle:

 Menstrual Cycle: The reproductive cycle in the female primates like
monkeys, apes and human beings is called as the menstrual cycle. The
cycle of events starting from one menstruation till the next one is called
menstrual cycle. This cycle is essential for the production of oocytes and for
the preparation of uterus for pregnancy. Thecycle repeats 28-35 days and
normally one egg is released per cycle.

 Menstruation: Menstruation is the process by which blood and mucosal
tissue are regularly discharged in a periodic manner from the inner lining of
the uterus through the vagina. It is also known as a period or monthly.

 Menarche: Menarche is the first menstruation for a human female. It begins
at puberty. The actual age for menarche varies from person to person.
Menarche signals the beginning of reproductive age in females.

 Menopause: Menopause is the permanent ceasing of menstrual cycle in
females due to the depletion of oocytes as a result of aging. The age of
menopause varies from person to person. The average age of menopause is
between 45-50 years.

Phases of the Menstrual Cycle:

Menstrual cycle follows four phases:
1. Menstrual phase
2. Follicular phase
3. Ovulation
4. Luteal Phase

1. Menstrual Phase: This is the period of menstruation when the menstrual flow
occurs.

 It typically lasts from 3-5 days.

 There is breakdown of the endometrial lining of the uterus and
its blood vessels which forms a liquidsubstance that comes out of
the vagina.

 It occurs when the ovum released by the ovary is not fertilised.

 Lack of menstruation may indicate pregnancy

 Menstruation may also be affected due to stress, poor diet, poor health,
etc.

2. Follicular Phase: This is the phase of maturation of follicle

 The primary follicles in the ovary grow to form a fully mature Graafian
follicle.

 The endometrium of the uterus regenerates through proliferation.

 These changes in ovary and uterus are induced by ovarian hormones-
Luteinising Hormone (LH) andthe Follicle Stimulating Hormone
(FSH).

 The levels of gonadotropins gradually increase through the follicular phase

43

 The increased levels of-LH and FSH gonadotropins stimulate follicular
development. They alsostimulate secretion of oestrogens by the
growing follicles.

3. Ovulation/Ovulatory Phase: This is the phase of release of ovum from
ovary

 The levels of LH and FSH reach their peak at mid-cycle, around 14th day.
 LH surge: The rapid increase in LH mid cycle leading to maximum LH

level mid cycle is called as the LH surge. This induces the rupture of
the Graafian follicle and thereby the release of ovum.
 Ovulation: The process by which an ovum is released by a mature
Graafian follicle from the ovary. It is a result of the LH surge which
occurs mid-cycle around the 14th day.
4. Luteal Phase: This is the phase of formation of corpus luteum
 The remaining parts of the Graafian follicle after ovulation form the
corpus luteum. Corpus luteum is therefore the structure that is
formed the ruptured Graafian follicle.
 The corpus luteum secretes large amounts of progesterone which is
essential for the maintenance of endometrium. The endometrium is
necessary for the implantation of the fertilized ovum and other events
of pregnancy.

Fertilisation and Implantation:
 Fertilisation: It is the fusion of the sperm and the egg.
During fertilisation the sperm induces changes in the zona
pellucida layer of the ovum that block the entry of additional
sperms ensuring that only one sperm can fertilise an ovum.

44

 The secretions of the acrosome help the sperm enter the
ovum through the zona pellucida and the plasma membrane.

 This induces the secondary oocyte to complete meiosis. This is
again an unequal division. It results in the formation of a
second polar body and a haploid ovum.

 The haploid nuclei of the sperm and the ovum fuse to form a
diploid zygote. The zygote contains 46 chromosomes.

 The zygote undergoes mitotic cleavage as it moves along
the isthmus of the oviduct towards the uterus. It forms 2,
4, 8 and 16 daughter cells called as blastomeres.

 Morula: The embryo with 8-16 blastomeres.
 The morula continues division as it moves further along into

the uterus. The blastomeres arrange in to an outer layer
called as the trophoblast. The inner cell mass is attached to
the trophoblast.
 The trophoblast attaches to the endometrium
 The inner cell mass differentiates to form the embryo

 Pregnancy and Embryonic Development:
 After implantation finger-like projections called as chorionic villi
appear on the trophoblast.
 The chorionic villi are surrounded by uterine tissue and maternal
blood. It causes the chorionic villi and the uterine tissue to
become interdigitated with each other and jointly form a
structural and functional unit between the developing foetus and
the maternal body called as the placenta.
 Placenta supplies oxygen and nutrients to the developing embryo
and removes the carbon dioxide and excretory waste from the
foetus.

45

 The placenta is connected to the embryo through umbilical
cord. The embryo transports nutrients and wastesto and from
the placenta through the umbilical cord.

 Additionally the placenta functions as an endocrine gland. It

produces several hormones such as human chorionic

gonadotropin (hCG), human placental lactogen (hPL),

oestrogen, progesterone etc.



 Later in the pregnancy another hormone called as relaxin is
produced by the ovary.

 During pregnancy production of various hormones is increased.
These hormones include oestrogens, progesterone, cortisol,
thyroxine, prolactin, etc. High levels of these hormones are
essential for supporting foetal growth, metabolic changes in
pregnancy as well as maintenance of pregnancy.

 Soon after implantation the embryo differentiates into the outer
ectoderm and the inner endoderm. The mesoderm develops soon
after. These three tissues soon give rise to the tissues in the
body.

 The inner cell mass contains stem cells that have the ability to
give rise to all the tissues and organs in thebody.

Fetal development:

 1 month- heart is formed

 2 month- limbs and digits are formed

 3 months- most of the major organ systems are formed

 5 months- appearance of hair on the head and the first
movements of the foetus

 6 months- body is covered with fine hair, eyelids separate,
eyelashes are formed

 9 months – foetus is fully developed and ready for delivery

Parturition and Lactation:

46

 Gestation Period: The average duration of pregnancy is called as
gestation period. In humans the gestationperiod is 9 months

 Parturition: The process of childbirth by which the foetus is expelled
or delivered due to vigorous contractionsof the uterus.

 A fully developed foetus and placenta induces parturition. This causes
mild uterine contractions called foetal ejection reflex.

 This triggers the release of oxytocin from the mother’s pituitary.

 Oxytocin stimulates stronger uterine contractions which stimulates more
production of oxytocin

 The stimulatory positive feedback reflex continues between the uterine
contractions and oxytocin secretion. This leads to stronger and
stronger contractions till the baby is expelled out of the uterus through
the birth canal.

 Soon after the foetus is delivered the placenta is also delivered.

 Lactation: The production of milk by the mammary glands of the
females towards the end of the pregnancy is called lactation.

 Colostrum: The milk produced during the initial few days of lactation is
called as the colostrum. It is rich in antibodies that provide resistance
and immunity to the new-born.

PRACTICE QUESTIONS

1. Identify the follicular stage represented by given picture.

a. Morula
b. Gastrula
c. Blastula
d. Graafian follicle
2. What will happen to Graafian follicle after ovulation?

(a) It will rupture

(b) Graffian follicle changes into corpus luteum.
(c) It will increase in size
(d) It will be removed with ovum
3. Write the ploidy of primary oocyte and secondary oocyte.

(a) 2n, n

(b) n, n

(c) n, 2n

(d) 2n, 2n

47

4. Which one out of the following is a primary sex organ?
(a) Scrotum
(b) Epididymis
(c) Testis
(d) Prostate gland
5. Identify the embryonic stage represented by given picture. Also name part
labelled as A and B.

(a) A – Inner cell mass B – Trophoderm
(b) A – Trophoderm B – Blastomeres
(c) A – Trophoblast B – Inner cell mass
(d) None of above

6. Which of the following hormone is secreted by palcenta only
a. Progesteron
b. Estrogen
c. h CG
d. LH

7.After how many days of fertilization implantation occurs?

a. 5 days

b. 6 days

c. 7 days

d. 8 days

8. In human females oxytocin during parturition

(a) Stimulates pituitary to secrete vasopressin

(b) Causes strong uterine contractions during parturition process

(c) Stimulates mammary gland growth

(d) Is secreted by pineal gland
9. Which is the unpaired gland in human male reproductive system?
a. Prostate gland
b. Seminal vesicle
c. Bartholin gland
d. Cowper’s gland

10. In mammals testis are present in scrotal sacs because

a. of presence of urinary bladder

48

b. of the rectum
c. long vas deferens
d. requirement of low temperature for spermatogenesis

11. In humans the functional unit of testis is
a. Uriniferous tubule
b. Lobules
c. Seminiferous tubules
d. Malpighian tubule

12. During spermatogenesis how many spermatozoa are produced from a single
primary spermatocyte?
a. 1
b. 2
c. 4
d. 8

13. Which part of sperm I enters in egg in case of human beings?
a. Whole sperm
b. Only head
c. Head and middle piece
d. Head and acrosome

14. Location and secretion of Leydig cells are respectively
a. Liver , cholesterol
b. Ovary, progesterone
c. Ovary , estrogen
d. Testis, testosteron

15. The process of releasing female gamete from ovary is called as
a. Parturition
b. Ovulation
c. Implantation
d. Fertilisation

16. In human female eggs liberated from ovary are in
a. Secondary oocyte stage
b. Primary oocyte stage
c. Mature ovum
d. Oogonial stage

17. In case of absence of fertilization, corpus luteum
a. Stops progesterone secretion
b. Modifies into corpus albicans
c. Start to produce progesterone
d. None of above

18. In humans site of fertilization is
a. Ampullary – isthmic junction
b. Isthmus
c. Fimbrae
d. Uterus

19. Hormone responsible for ovulation is
(a) FSH
(b) ICSH

49

(c) LH
(d) Testosterone

20. Sertoli cells are regulated by hormone secreted from pituitary gland called
as

(a) FSH
(b) GH
(c) Prolactin
(d) LH

21. Identify the stage of embryo development shown in following figure and it’s
place of occurrence:

a. Late morula – Middle opart of oviduct
b. 8 celled stage – Starting point of oviduct
c. Blastula – End part of oviduct
d. Blastocyst – Uterine wall

22. The male germ cell undergoes divisions to produce sperms. Then choose
the correct statement from given below:
a. Spermatogonia contain 46 chromosomes and undergo meiosis always
b. Primary spermatocyte undergoes mitosis
c. Secondary spermatocyte contains 23 chromosomes and performs second meiosis.
d. Spermatozoa are transformed into spermatids.

23. Morula is the developmental stage
a. Between zygote and blastocyst
b. Between blastocyst and gastrula
c. After implantation
d. Between implantation and parturition

24. Identify the odd one from the following options.
(a) Fimbriae
(b) Infundibulum
(c) Labia majora
(d) Isthmus

25. Low level of progesterone and estrogen causes production of
(a) FSH
(b) LH
(c) FSH – RH
(d) GH

ANSWERS

Question Number Answer
1
(d) Mature follicle/Graffian follicle
2 (b) Graffian follicle changes into corpus luteum.

50