During sexual reproduction in humans: - Gametes are produced during puberty through processes like meiosis which create haploid cells. - Fertilization occurs when a sperm cell fuses with an egg cell internally, forming a zygote with a full complement of DNA. - The zygote then divides many times to form an embryo that develops further into a fetus in the uterus, receiving nutrients via the umbilical cord.

1. CH-8:- HOW DO ORGANISMS
REPRODUCE?
• CLASS:- X
• SUB:- SCIENCE
PART-2

2. Reproduction :-
Reproduction is the process by which living organisms
produce new individuals of the same species from the
existing organisms.
Reproduction is necessary for the survival and increase in
the population of a species. If organisms do not reproduce,
their population decreases and species will become extinct.
Do organisms create carbon copies ofthemselves ?
 The DNA (Deoxyribo nucleic acid) molecules in the
chromosomes in the nucleus is responsible for the
transfer of characters from the parents to the off springs.
 During reproduction the reproductive cells produce two
copies of the DNA which separate into two cells.
 The DNA copies will be similar but not identical to each
other. So the new individuals have slight variations from
their parents. This is the basis for variations and
evolution of new species.

3. 3) The importance of variation :-
DNA copying during reproduction is important for
maintaining the body designs of different organisms to
survive in the existing environment. But the environment
constantly changing due to changes in temperature, climate,
water levels etc. If organisms cannot adjust themselves to
the changes in the environment then their species will
become extinct.
 If there are variations in some individuals of a species
they may be able to survive the changes in the
environment.
Eg. Moth:- White colour Moth was easily visible to eagle and
were hunted but black colour Moth was not visible, so they
were protected. Because of this variation, black one was
able to survive due to variation.
 So variations in species is necessary for the survival of
different species and for the evolution of new species.
is

4. • Germ cells:- Cells that create
reproductive cells (gametes).
• Gamete:- It is a haploid cell that
fuses with another haploid cell
during fertilization in organisms that
sexually reproduce.
 Male gamete:- Sperm
 Female Gamete:- OVA
• Karyokinesis:- Process of division of a
cell's nucleus during the cell division
processes like mitosis and meiosis.
• Cytokinesis: Process of cell division,
which divides the cytoplasm of a
parental cell into two daughter cells.
• Zygote:-First diploid cell that forms
after the fusion of male and female
gamete.

5. 4) Types of reproduction :-
There are two main types of reproduction in living organisms. They
are asexual reproduction and sexual reproduction.
Asexual reproduction :- is reproduction in which new individuals
are produced from a single parent.
Sexual reproduction :- is reproduction in which two individuals
are involved to produce a new individual.
Asexual reproduction is of different types. They are:- fission,
budding, regeneration, fragmentation, spore formation, vegetative
propagation etc.

6. SEXUAL REPRODUCTION IN
FLOWERING PLANTS

7. Sexual Reproduction in Flowering
Plants
• Those plants which bear flowers are called Flowering
Plants. (Angiosperm)
• The plants in which the sex organs are carried within the
flowers and seeds are enclosed in a fruit are called
Angiosperm.
• Flowering plants reproduce by sexual reproduction method.
• Means two sex organs are involved:-
 Male Sex organs- Androecium (Consist of Stamen-
Filament & Anther)
 Female Sex Organ- Gynoecium (Consist of Carpel- Stigma,
Style & Ovary)

9. • Most flowers have both the male and female
reproductive organs:- Bisexual Flowers
E.g., Hibiscus, pea, etc.
• Some Flowers which bear either the male or the
female sex organs:- Unisexual flowers
E.g., watermelon, cucumber, etc.
• A flower generally bears a long or short axis.
• This axis has two parts—the stalk of the flower,
called pedicel, and its swollen top called
thalamus. The parts of a flower are arranged on
the thalamus (Figure6.7).

10. Male Sex organs- Androecium
Female Sex Organ- Gynoecium

11. Parts of the Flower
1. Receptacle:- The base of the flower to which all the parts of a
flower is attached.
2. Calyx:- Calyx is the outermost whorl. It consists of sepals. The
sepals are usually green, but sometimes they may be coloured.
Calyx protects the floral whorls in the bud stage.
3. Corolla:- Corolla, the next inner whorl, consists of petals.
Petals may be white or brightly coloured. They attract insects
towards the flower and thus help in pollination. Corolla protects
the reproductive whorls in the bud stage.
4. Androecium:- The stamens are collectively called androecium,
which is the third whorl. Each stamen consists of a filament and
an anther. Each anther has two chambers called pollen sacs. If
we touch the stamens of a flower, a yellowish powder may come
off on your hands called Pollen grains. Anthers produce these
numerous yellowish pollen grains, which contain male gametes.

13. Male Sex organs- Androecium
Female Sex Organ- Gynoecium

14. 5. Gynoecium:- The gynoecium (or pistil) is in the centre
of the flower.
• It is the fourth whorl.
• It bears the female reproductive organ, called carpel.
• Each carpel consists of three parts—a basal swollen
portion called ovary, a narrow stalk like middle portion
called style and a one- to many-lobed flattened disc
like sticky structure called stigma at the top of the
style.
• The ovary is surrounded by an outer wall. The ovary
may be divided into chambers. The chambers contain
ovules. Each ovule has an egg cell (female gamete).

15. Sexual Reproduction in flowering Plants

16. b) Pollination :-
The transfer of pollen grains from the anther to the stigma
of a flower is called pollination. It takes place by wind, water or
insects. If the pollen grains are transferred from the anther to the
stigma of the same flower it is self pollination and if it is
transferred from the anther of one flower to the stigma of another
flower is called Cross Pollination.
Cross Pollination
Self pollination

17. Agents for Pollination
• Anemophily:- a form of pollination where pollen is distributed by
wind.
• Zoophily:- a form of pollination by insects, birds, bats, snails or
other animals.
 Entomophily:- a form of pollination where pollen grains of
flowering plants are distributed by insects.
 Ornithophily:- a form of pollination which takes place with the
help of birds.
 Chiropteriphily:- a form of pollination which takes place with the
help of bats.
 Malacophily:- a form of pollination which takes place with the
help of snails.
• Hydrophily: a form of pollination in which pollen is carried to a
flower with the help of water.

18. c) Fertilisation :-
After the pollen grain is
transferred to the stigma it
produces a pollen tube which
passes through the style and
enters the ovary and ovule. In
the ovule the male germ cell
(male gamete) fuses with the
female germ cell (female
gamete) to form a zygote. This
process is called fertilisation.
After fertilisation the zygote
divides several times and forms
the embryo which then develops
into the seed and the ovary
develops into the fruit.

20. Formation of Seeds and Fruits
• After the fertilization of eggs(zygote), it divides several times to form
a embryo within the ovule.
• The ovule develops a tough coat around it and is gradually converted
into a seed (containing baby plant).
• A seed is the reproductive unit of a plant which can be used to grow a
new plant.
• The Ovary of flower develops and becomes a fruit (with seeds inside
it).
• The other part of flower like sepals, petals, stamens and style dry up
and fall. Only ovary is left behind.
• Now at the place of flower, we have a fruit.
• A fruit protects the seeds.
• Some fruits are soft, sweet and juicy like mangoes, and oranges etc.
while some fruits are hard, dry, and woody like the peanuts and
almonds etc.

22. Seeds
• Seed:- Reproductive unit of a plant.
• A structure that encloses the embryo of a plant in a
protective outer covering.
• Under favorable conditions of growth, a seed gives rise
to a new plant, using the nutrients stored in them.
• The union of the male and female reproductive cells
inside the ripened ovule of a flower, helps in the
formation of seeds in a plant.
• Different seeds have different sizes, shapes, and colors
that participate in the reproduction of flowering plants.

24. A typical seed consists of three main parts:
1) Seed coat
2) Endosperm
3) Embryo.

25. 1. Seed Coat
• They are the protective outer covering of a seed that is usually
hard, thick, and brownish in color.
• The seed coat is formed from the outer covering of the ovule
called the integument.
• It usually contains two layers: i) testa – the thick outer layer,
and ii) tegmen – the delicate inner layer.
• Functions of Seed coat:
 Protecting the seed from physical and mechanical damage
 Preventing the seed from germination even under
favorable conditions of growth (seed dormancy).
 Preventing the excessive loss of water from the seeds.
 Acting as a physical barrier against the entry of parasites.

26. 2. Endosperm
• It is a tissue that is rich in oil, starch, and protein.
Depending on the presence or absence of endosperm,
seeds are of two types:
 i) Non-endospermic or exalbuminous seeds – Characterized
by the complete absence of the endosperm, such as the
seeds of the pea plant, groundnut, and gram.
 ii) Endospermic or albuminous seeds – Characterized by the
presence of the endosperm, such as the seeds of millets,
palms, and lilies.
• Storing of reserve foods that provide nourishment to the
developing plant
• Protecting the embryo, the next part of the seed, by acting as the
mechanical barrier

27. 3. Embryo
• They are the young plant that is developing inside the seed coat.
• An embryo contains the underdeveloped tissues of leaves, stem, and roots
of a plant.
Parts of an Embryo
• a) Epicotyl – The tiny shoot of an embryo, from which the entire shoot
system develops. The tip of the epicotyl is called plumule.
• b) Hypocotyl – The stage of transition for the growing shoot and root of
the embryo
• c) Radicle – The tiny root of the embryo
• d) Cotyledons – They are the leaves of the embryo that provide
nourishment to the developing plant. There are two types of cotyledons
present in flowering plants: i) monocotyledonous or monocots – embryo
with one cotyledon ii) dicotyledonous or dicots – embryo with two
cotyledons.
 Functions: 1. Giving rise to a new complete new plant,
2. Storing food and nourishing to the baby plant

28. Germination of Seeds
• Fundamental process by which different plant species grow from
a single seed into a plant is called Germination of seeds.
• Seeds obtained from the plant are usually dry and are in inactive
state i.e. in dormancy.
• But when its gets adequate temp., water and nutrients, it gets
germinated.
• Germination begins when the seeds absorb water, swells, and
bursts through the seed coat.
• The water helps the enzyme to function in the seed.
• The enzyme digest the stored food in cotyledons and make it
soluble.
• This soluble food makes the radicle and plumule present in the
seed to grow.

29. • The radicle of the seed grows first to form the root.
• The root pushes down into the soil and begins to absorb water
and minerals from the soil.
• After this, the plumule grows upwards to form the shoot.
• When the shoot comes up above the ground, it develops green
leaves.
• The green leaves of the shoot begin to synthesise own food in the
presence of sunlight.
• Then seedling grows gradually and finally becomes a new plant.

30. SEXUAL REPRODUCTION IN
HUMAN BEINGS

31. Important terms related to Reproductive
System in Animals
• Germ cells:- Cells that create reproductive cells called gametes.
• Gamete:- It is a haploid cell that fuses with another haploid cell
during fertilization in organisms that sexually reproduce.
 Male gamete:- Sperm
 Female Gamete:- OVA
• Zygote:-First diploid cell that forms after the fusion of male and
female gamete. Zygote is a fertilized egg or ovum.
• Fertilization:- The fusion of a male gamete with a female gamete
to form a zygote during sexual reproduction.
• Embryo:- The unborn baby in the uterus in the early stages of
development (when its body parts are not much developed).

32. • Foetus/Fetus:- The unborn baby in the uterus in the later stages
of development (when its body parts are well developed and can
be identified).
• Internal Fertilization:- Which occurs inside the female body.
Eg- Mammals, Birds, and Reptiles, etc.
• Copulation:- Act by which male animals transfers his sperms into
the female body.
• External Fertilization:- Which occurs outside the female body. In
this male and female animals release their sperms and eggs in
water where fertilization takes place by collisions between
sperms and eggs. Eg- In Amphibians, fishes, etc.
• Umbilical Cord:- The umbilical cord is a narrow tube-like
structure that connects the developing baby to the placenta. The
cord is sometimes called the baby's “supply line” because it
carries the baby's blood back and forth, between the baby and
the placenta. It delivers nutrients and oxygen to the baby and
removes the baby's waste products.

33. Advantages of Sexual Reproduction
• Offspring are not identical to their parents or one
another.
• produces genetic variation in the offspring.
• The species can adopt to new environments due
to variation, which gives them a survival
advantages.
• a disease is less likely to affect all the individuals
in a population.

34. Why the amount of DNA does not get doubled
during sexual reproduction?
• The gametes are special types of cells called reproductive cells
which contain only half the amount of DNA (or half the
number of chromosomes) as compared to the normal body
cells of an organism.
• So, when a male gamete combines with a female gamete
during sexual reproduction, then the new cell ‘zygote’ will
have the normal amount of DNA (or normal number of
chromosomes in it).
• For example, the human sperm has 23 chromosomes and the
human egg (or ovum) has also 23 chromosomes.
• So, when a sperm and an egg fuse together during
fertilization, then the zygote formed will have 23 + 23 = 46
chromosomes, which is the normal number of chromosomes
in human beings.

35. During sexual reproduction the amount of DNA does not get doubled because
:---
●We know that gametes are always haploid so the sperm from man has 23
chromosomes and similarly the egg has 23 chromosomes, so when they fuse
they give rise to organism having 46 chromosomes hence restoring amount of
DNA and number of chromosomes.
●During reproduction the germ cells have half the number of chromosomes
and DNA as compared to non-reproducing cells.
●As the offspring receives only one copy from each parent, thus maintaining
amount of DNA .
●If it gets double then each next generation would end up having double
amount of DNA as previous generations so at then end a stage will be there
when there will only be DNA and no other cells.
●Hence to resolve this problem the DNA does not get doubled in next.
During sexual reproduction the amount of DNA does
not get doubled. Why ?

36. How Sexual Reproduction in Human
takes Place?

37. Adolescence
• When a child is small, sometimes it become difficult to tell
from appearance whether it is a boy or girl.
• Then a time of rapid growth and body changes starts early
teens which makes the boy and the girl appear different and
also behave differently.
• So Adolescence is the transitional stage of physical and
psychological development that generally occurs during the
puberty to adulthood.
• Adolescence usually associated with the teenage years, but its
physical, psychological or cultural expressions may begin
earlier and end later. Eg. Puberty now typically begins during
preadolescence, particularly in females.

38. Puberty
• The age at which the sex hormones (or gametes) begin to
produce and the boy and girl become sexually mature (able to
reproduce).
• Puberty tends to start earlier in females (girls) than in males
(boys).
• Boys attain puberty at the age of 13 to 14 years while girls
reach puberty at the age of 10 to 14 years.
• On attaining puberty, the male gonads called testes start
producing male gametes called Sperms and female gonads
called ovaries start producing female gametes called ova (or
eggs).
• In addition to the production of gametes, these gonads also
start producing and secreting sex hormones with onset of
puberty. Testes:-Testosterone, Ovaries:-Oestrogen (estrogen)
& Progesterone

39. Hormonal Control of Puberty
• As shown in the diagram below, in both boys and girls, the
changes of puberty are triggered by the hypothalamus in the
brain.
• For unknown reasons, the hypothalamus starts releasing
pulses of gonadotropin-releasing hormone (GnRH).
• This hormone travels directly to the anterior pituitary gland
and stimulates it to secrete hormones that target the gonads
(testes in males and ovaries in females).
• The main pituitary hormones are follicle-stimulating hormone
(FSH) and luteinizing hormone (LH).
• FSH stimulates the testes to produce sperm and follicles in the
ovaries to mature and secrete estrogen.
• LH stimulates the testes to secrete testosterone and the
ovaries to secrete estrogen.

40. • Testosterone and estrogen, in turn, stimulate the development
of primary and secondary sex characteristics and contribute to
the spurt in physical growth.
Figure shows Hormonal regulation of the male reproductive system: GnRH stimulates the production of
FSH and LH, which act on the testes to begin spermatogenesis and to develop secondary sex characteristics in
the male. In turn, the testes production of testosterone and the hormone inhibin inhibit the release of GnRH,
FSH, and LH in a negative feedback loop.

41. Various changes at Puberty
1. Changes in Boys:
 Hair growth in armpits and pubic region (genital area) between
the thighs, and other parts of body like chest, moustache, beard
etc.
 Body becomes more muscular due to development of muscles.
 The voice deepens (or cracks).
 Chest and shoulders broaden.
 The penis and testes become larger.
 The testes start to make sperms.
 Feelings and sexual drives associated with adulthood begin to
develop.
 All these changes in boys are brought about by the male sex
hormone ‘testosterone’ made in testes.

42. Various changes at Puberty
2. Changes in Girls:
 Hair growth in armpits and pubic region (genital area) between
the thighs.
 Mammary glands (or breasts) develop and enlarge.
 The hips broaden. Extra fat is deposited in various parts of the
body like hips and thighs.
 Fallopian tubes, uterus and vagina enlarges.
 Ovaries start to release eggs.
 Menstruation (monthly periods) start.
 Feelings and sexual drives associated with adulthood begin to
develop.
 All these changes in girls are brought about by the female sex
hormones ‘Oestrogen (estrogen)’ and ‘Progesterone’ made in
ovaries.

43. 6) Reproduction in human beings :-
a) Male reproductive system :-
The male reproductive system consists of a pair of testes which
produces the male reproductive cells called sperms and the hormone
testosteron. It is contained in sac like structures called scrotum. From
each testis arises a tube called vas deferens. It joins into the urethra.
The urethra is enclosed in a muscular organ called penis. It has an
opening called genital pore. The seminal vesicles and prostate glands
produce fluids which provide nutrition and help in the movement of the
sperms.
Sperm

45. Why testes are outside the abdominal cavity?
• Testes are outside the abdominal cavity
because the sperm formation requires a lower
temperature than the normal body
temperature.
• Being outside the abdominal cavity, temp. of
the scrotum sac is about 30 C lower than the
temp inside the body.
• In this way testes provide the optimal temp. for
the formation of sperm.

46. Structure of Sperm

47. Sperm Production to Ejaculation
• Sperms are formed in the testes.
• After this, sperms come out and go into a coiled tube called Epididymis. Here it
stored temporarily.
• From Epididymis, sperms are carried by a long tube called Vas deferens (sperm
duct) which joins with another tube called Urethra coming from the bladder.
• Along the path of vas deferens, the glands called Seminal Vesicles and Prostate
glands add their secretion to sperm so that the sperms are now in liquid.
• This liquid plus the sperm it contains is called Semen (which is a thick liquid).
• The secretion of seminal vesicles and prostate gland provide nutrition to the
sperms and also make their further transport easier.
• Urethra forms a common passage for sperms and urine.
• Urethra carries the sperms to an organs called Penis which opens outside the
body.
• In man, there is only one opening for the urine and sperms to pass out of the
body.

49. b) Female reproductive system :-
The female reproductive system consists of a pair of ovaries which
produces the female reproductive cells called ova or eggs and the
hormone oestrogen and Progesterone. Each ovary is composed of
several thousand follicles which are a kind of unripe eggs or unripe
ova. At puberty these follicles mature to form the ripe eggs.
Human ovum (egg)

50. • Oviducts (Fallopian Tube):- Present just above the ovaries.
Ovaries are not directly connected to it but it has a funnel
shaped or finger like projections which almost covers the
ovaries. The ovum or egg released by an ovary goes into the
oviduct through this funnel shaped opening. The fertilization of
egg/ova by a sperm takes place in this only.
• Uterus (Womb):- It is a hollow pear shaped muscular organ
located in pelvis between the bladder and rectum through
which both oviducts are connected. It is within the uterus, fetus
develops during gestation period. The inner lining of uterus
called Endometrium protects and nourishes the developing
embryo.
• Endometrium:- It is one of the most important part of female
reproductive system which plays key roles during menstrual
cycle as well as during pregnancy. It is also called endometrial
lining, the tissue it’s made up of serves as the “wallpaper” of
the uterus, or womb that houses/nourishes a developing baby.

51. • Cervix:- It is cylindrical-shaped tissue that connects the vagina
and uterus. It is located at the lowermost portion of the uterus,
the cervix is composed primarily of fibromuscular tissue. The
cervix produces cervical mucus that changes in consistency
during the menstrual cycle to prevent or promote pregnancy.
During child birth, cervix dilates widely to allow the baby to pass
through. And during menstruation, cervix opens a small amount
to permit passage of menstrual flow.
• Vagina:- It is an elastic, muscular canal with soft, flexible lining
that provides lubrication and sensation. Uterus open into vagina.
The vagina receives the penis during sexual intercourse and also
serves as a passage for menstrual flow from the uterus. It is also
known as birth canal because it is through which this passage
baby is born after the completion of development inside the
uterus of the mother.

52. • Bartholin’s Gland:- Are located just near to vaginal opening. They
release fluid that lubricates vagina.
• Skene’s Gland:- Are located on the either side of the urethral
opening. They release fluid during female ejaculation . They are
also called para-urethral gland or female prostate glands.
Note:- In human female, the opening for passing out urine called
Urethra and the vaginal opening are separate.

54. c) Fertilisation in human beings :-
During sexual intercourse, millions sperms from the male enters into
the vagina of the female. The sperms reaches the oviduct through
cervix and uterus. One sperm fuses with an egg and forms a zygote.
The zygote then gets implanted in the uterus. The zygote then starts
dividing to form an embryo. The embryo gets nutrition from the
mother’s blood through the placenta. The development of the child
takes nine months and then the child is born.

55. Development of Embryo
• After the fertilization of ovum, zygote is formed.
• The zygote divides rapidly by mitosis as it moves down slowly in the
oviduct and forms a hollow ball of hundreds of cells.
• This hollow ball of cells, now called embryo, which sinks into soft and
thick lining of uterus and gets embedded in it.
• This embedding of embryo in the thick lining of the uterus is called
Implantation.
• After implantation, a disc like special tissue develops between the
uterus wall or uterine wall and the embryo which is called as Placenta.
• The foetus is connected to placenta in mother’s body through umbilical
cord.
• The exchange of nutrients, oxygen and waste products between the
embryo and the mothers takes place through placenta via umbilical
cord.

56. Gestation Period
• The time period from the fertilization up to the birth of the
baby is called Gestation Period.
• The average gestation period in human is about nine months
or about 38 weeks.
• During the gestation period, the foetus grows to become a
baby.
• Birth begins when the strong muscles in the walls of the
uterus start to contract rhythmically.
• The rhythmically contraction of uterus muscles gradually
pushes the baby out of the mother’s body through vagina.

57. Stages in the early development of the embryo

61. Diploid Haploid
About Diploid cells contain two
complete sets (2n) of
chromosomes.
Haploid cells have half the
number of chromosomes (n) as
diploid - i.e. a haploid cell
contains only one complete set
of chromosomes.
Cell Division and
Growth
Diploid cells reproduce by
mitosis making daughter cells
that are exact replicas.
Haploid cells are a result of the
process of meiosis, a type of cell
division in which diploid cells
divide to give rise to haploid
germ cells. A haploid cell will
merge with another haploid cell
at fertilization.
Examples Skin, blood, muscle cells (also
known as somatic cells)
Cells used in sexual
reproduction, sperm and ova
(also known as Gametes).
Comparison chart b/w Haploid and Diploid

62. Differences b/w Gamete-Zygote-Embryo-Foetus

64. Sexual Cycles in Females:- Menstruation
• As we know, when a girl child is born, her ovaries already contain many
thousands of immature ova or eggs which are contained in immature
follicles.
• When a girl reaches the age of puberty, then one follicle develops at a
time to form a mature ovum or egg.
• On maturing, the follicle bursts and the ovum or egg shoots out of the
ovary which is called Ovulation.
• In other words, the release of an ovum or egg from an ovary almost
once every month is called ovulation.
• In a normal, healthy girl or woman, ovulation takes place on the 14th
day of the beginning of menstrual cycle of 28 days. This means that
ovulation takes place in the middle of the menstrual cycle (because
14th day is the middle of 28 days).
• In human female or girls, the ovaries start releasing ovum or egg or
female gamete once every 28 days from the age of puberty.

65. 1. When a girl reaches puberty at the age of about 10-12 years, the sex
hormone released into her blood cause some of the ova in her ovaries
to become mature (or ripe).
2. Usually one mature ovum is released from the ovary into the oviduct
once every 28 days which is called ovulation.
3. Before ovulation or release of ovum, the inner lining of uterus
becomes thick and spongy, and the full of tiny blood vessels or blood
capillaries, and prepares itself to receive the fertilized ovum or egg (in
case it gets fertilized by sperm).
4. If the ovum does not get fertilized due to non availability of sperm in
the female body) then the thick and soft lining of uterus is no longer
needed and hence it breaks. So, the thick and soft inner lining of
uterus along with blood vessels and the dead ovum comes out of the
vagina in the form of a bleeding called menstruation.
Sexual Cycles in Females:- Menstruation

66. 5. Menstruation usually occurs 14th days after ovulation and
usually lasts for about 3 to 5 days.
6. After menstruation is over, the inner lining of the uterus starts
building up again so that it may become ready to receive the next
ovum or egg in case it gets fertilized.
7. If the ovum or egg does not get fertilized even now, then
menstruation takes place again.
This cycle of menstruation is repeated again and again in woman
after every 28 days till the time ovum gets fertilized.
And if the ovum gets fertilized then the woman become pregnant
and after the birth of child it restarts again.

67. Menarche and Menopause
 The first occurrence of menstruation or periods at puberty is
called Menarche which starts when the girl reaches at the age
of puberty or around 10 to 12 years of age.
 The permanent stoppage of menstruation or periods in a
woman is called Menopause which occurs in the female after
the age of 45 to 50 years.
 In this stage, ovary does not release eggs hence ovulation stops
and woman can not become pregnant now.
 It is the end of the reproductive life of the female.
 Therefore we can say that the reproductive life of woman
starts at Menarche and ends at Menopause.

68. Birth Control
• As we already know, population of our country is increasing day by
day and due to this rise of population, our governments are unable
to provide adequate food, clothing, housing facility, proper
education and employment to may people.
• It is therefore very important for the couples who are in the
reproductive stage of their lives to control the size of their families
by having fewer children by practising family planning through
birth control measures having small family and happy family.
• Birth control can be done by preventive pregnancy in females or
woman.
• Pregnancy can be prevented by adopting a method or procedures
by which sperms produced during copulation between man and his
wife can be prevented from meeting the ovum and fertilizing it.

69. Birth Control Measures
• The prevention of pregnancy in women by preventing fertilization
is called Contraception.
• Any device or chemical or drug which prevents pregnancy in
woman is called Contraceptive.
• The various birth control methods are as follows:-
1. Barrier Methods
2. Chemical Methods
3. Surgical Methods

70. 1.Barrier Methods:- In this methods, physical devices like
condoms and diaphragm (or cap) is used. Condoms are used by
males (by putting them as a covering on the penis). Diaphragm
(or cap) is used by females (by putting it in the vagina to cover
the cervix). These devices prevents sperms from meeting the
ovum or egg by acting as a barrier between them. Condom is
the only method of contraception which also protects the
person from sexually transmitted diseases.
2.Chemical Methods:- In this method, the females use two types
of pills: oral pills and vaginal pills to prevent pregnancy. Oral pills
contain hormones which stop the ovaries from releasing ovum
or eggs into the oviduct if it is taken at right time to prevent
pregnancy but there is also some side effects like hormonal dis-
balance etc. due to its excess use. The vaginal pills contain
chemical called spermicides which kill the sperms in the vagina.

71. 3. Intra-Uterine Contraceptive Devices(IUCD):- In this method, a
IUCD device called Copper-T is placed inside the woman uterus by
a doctor or a trained nurse. This Copper-T prevents the
implantation of fertilized egg in the uterus. It is also a very effective
methods in preventing pregnancy. But by this method woman can
not be protected from sexually transmitted disease if her partner
has such a disease.
4. Surgical Methods:- This methods of birth control are available
for both males and females. In males, a small portion of the sperm
duct (vas deferens) is removed by surgical operation and both the
cut ends are tied or ligated properly. This prevents the sperm
coming out. This process in males is called Vasectomy. In females,
a small portion of the oviduct is removed by surgical operation and
cut ends are ligated or tied which prevents the ovum or egg from
entering into the oviduct. This method in females is known as
Tubectomy.

73. Reproductive Health
• A total well-being in all aspects of reproductive, i.e, physical, emotional,
social and behavioural is called Reproductive health.
• Contraception:- It is the avoidance of pregnancy.
• Sexually transmitted diseases (STDs):- The diseases which are spread by
sexual contact with an infected person are called STDs. In this, a healthy
person get infected by having sex with an infected person. Some of the
STDs are:- Gonorrhoea, Syphilis, Trichomonas, AIDS etc.
 Gonorrhoea and Syphilis are caused by bacteria. The common symptoms
are sensation at urination, passing of urethral discharge containing pus and
sores at genitals.
 Trichomonas is caused by protozoans parasite called Trichomonas vaginalis.
 Gonorrhoea, Syphilis and Trichomonas are curable disease.
AIDS (Acquired Immune Deficiency Syndrome) is cause by a deadly virus
called HIV (Human Immunodeficiency Virus). This virus damages the patients
body immune system in which patients body becomes weak and cannot
protect themselves against infection and hence leads to death. Till now there
is no definite cure of this deadly virus.

74. Sexually Transmitted Diseases (STD)
• Gonorrhoea- Caused by the bacteria Neisseria gonorrhoeae.
• Syphilis- Caused by the bacteria Treponema pallidum
• AIDS- Caused by HIV (Human Immunodeficiency Virus)

75. Stop Female Foeticide!
• In our country, people are misusing the surgical operation and
Sonography test to get rid of female foetus or girl child.
• In order to have a male foetus, some misguided people get the
sex of the unborn child determined by ultra sound techniques
and if it is female foetus then they get removed by surgery.
• For a healthy society, the male-female sex ratio must be
maintained at almost the same level.
• Because of this killing, the girls population in our society is
decreasing day by day.
• We should not forget our mother, sisters and our wife’s are
female. Then why not have a female as our daughter?
• The person who blames their wives for having a girl child, he
should not forget that only male is responsible for having a male
or female child because of having XY chromosome.

76. Healthy society needs a balanced sex ratio that can
be achieved by educating people to avoid
malpractices like female foeticide & prenatal sex
determination.
Even our govt. has banned prenatal sex
determination.
Agar beti ko marvaoge, Tab dulhan kaha se
laoge!