ICSE EIGHTH GRADE

1. Draw or type 2 things you already know about today’s topic:

2. Reproduction in
Humans
Jegatheeswari Karthik

3. Reproduction
It is the process in which the organisms give rise to new individuals of
their own kind.
It helps in continuation of the species.
Different organisms reproduce in different ways.
Two different types of reproduction in Animals.
1. Asexual reproduction
2. Sexual reproduction

4. Asexual reproduction in Animals
● Fission
A. Binary fission
B. Multiple fission
● Budding
● Regeneration

5. Fission
● Common in single-celled organisms
● Fission means Splitting
● Two types
● Binary fission (Two) - Amoeba , Paramecium
● Multiple fission (Many) - Plasmodium

6. Steps in fission
Parent cell
Nucleus division
Cytoplasm division
Daughter cell formation

8. Binary fission in Paramaecium
● Longitudinal division

9. Reproduction in paramecium

10. Budding
Buds grow on outside of the parent body
Buds later detach themselves when it become big enough
Eg. Hydra

12. Regeneration
● Few animals have the capacity to regrow the missing or
lost parts of their body.
● The process of generating lost parts is called
regeneration.
● E.g. Hydra, Starfish, Planaria
● If hydra is cut transversely into two 2-3 pieces each will
regenerate and give rise to new individual.

13. Planaria Regeneration
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14. Sexual Reproduction in Animals
● Male and female produce special type of reproductive
cells.
● Males produce male gametes or sperm cells.
● Females produce the female gametes or egg cells or ova.

15. Fertilisation and Development
● Sperm and ovum fuses and fertilisation occurs.
● Sperm and ovum fuse to form a zygote.
● The zygote grows to form a embryo.
● Embryo grows into a new individual

16. Sperm and egg cell

17. Fertilisation and development

18. Make connections
How are these two things connected?
What connects these concepts?
Reproduction in Plants
Reproduction in
Animals

19. Human reproductive system
● Female reproductive system parts
1. Uterus
2. Ovary
3. Oviduct or Fallopian tube
4. Cervix
5. Vagina

20. Human reproductive system

21. Ovary
● There are two ovaries present one on either side of the
uterus.
● Ovaries are whitish oval bodies, lying within the lower
half of the abdomen.
● The ovaries function is to produce eggs.
● Only one egg is produced by an ovary alternatively every
month.

22. Fallopian tube
● Also called as oviducts.
● A pair of narrow, muscular, long ducts extends from each
ovary to the upper part of the uterus.
● Mouth of the oviducts is expanded to form a funnel-
shaped structure.
● Through this the egg enters the uterus.

23. Uterus
● Is a hollow, inverted pear-shaped muscular organ found in
the pelvic cavity between the urinary bladder and the
rectum.
● Embryo grows and develops in the uterus.

24. Vagina
● The uterus opens to the outside through a long, muscular
tube called the vagina.
● Situated between the rectum and Urethra.
● Through this the male gamete enters
● It serves as a Birth Canal

25. Cervix
● The cervix is a cylinder-shaped neck of tissue that
connects the vagina and uterus. Located at the
lowermost portion of the uterus, the cervix is composed
primarily of fibromuscular tissue.

26. Male reproductive system
● Testes or testicles
● Scrotum
• The duct system, which is made up of the
epididymis and the vas deferens
• The accessory glands, which include the seminal
vesicles and prostate gland.
• The Cowper’s gland
• The penis

28. Testes or testicle
● Oval shaped
● Pair of testes lie outside the abdominal cavity in a sac
called scrotum.
● The testes consists of mass of sperm –producing tubes.
● These tubules are responsible for producing the sperm cells
through a process called spermatogenesis.
● Testes has two main functions
1. Produce male gametes or sperms
2. Produce Testosterone.

29. Scrotum
The scrotum is the loose pouch-like sac of skin that hangs
behind the penis.
It contains the testicles (also called testes), as well as many
nerves and blood vessels.
The scrotum has a protective function and acts as a climate
control system for the testes. For normal sperm development,
the testes must be at a temperature slightly cooler than the
body temperature.

30. Scrotum
● Usually it maintains 2-3 degree Celsius lesser than body
temperature.
● This is the suitable temperature for sperm production and
development.

31. Duct system
● Includes epididymis and the vas deferens.
● The epididymis is a long, coiled tube that rests on the
backside of each testicle.
● Two main functions
1. Store male gamete.
2. It bring the sperm to maturity, since the sperm that
emerge from the testes are immature and incapable
of fertilization.

32. Duct system
● Includes epididymis and the vas deferens.
● The vas deferens is a long, muscular tube that travels from
the epididymis into the pelvic cavity, to just behind the
bladder.
● The vas deferens transports mature sperm to the urethra.
● It is also called Sperm duct.
● Two sperm ducts arise one from each testes.

33. Accessory glands
● Includes the seminal vesicles and prostate gland.
● The seminal vesicles are sac-like pouches that attach to the
vas deferens near the base of the bladder.
● The seminal vesicles produce a sugar-rich fluid (fructose)
that provides sperm with a source of energy and helps with
the sperms’ motility (ability to move).

34. Semen
● Is a mixture of Sperms and secretions from seminal
vesicles, Prostate and Cowper’s glands.
● Is a milky white fluid.
● It’s average amount is 2-3 ml
● Contains 20,000,000 - 40,000,000 sperms.

35. Accessory glands
● Includes the seminal vesicles and prostate gland.
● The prostate gland is a walnut-sized structure that is
located below the urinary bladder.
● The prostate gland pours an alkaline secretion into the
semen as it passes through the Urethra.
● Prostate fluids also help to nourish the sperm.

36. Cowper’s gland
● Are two small ovoid glands found below the Prostate
gland.
● It will secrete some secretions.
● It will serve as Lubricants.

37. Penis
● The penis is actually made up of two parts: the shaft and
the glans.
● The shaft is the main part of the penis and the glans is the
tip (sometimes called the head).
● At the end of the glans is a small slit or opening, which is
where semen and urine exit the body through the urethra.
● The inside of the penis is made of a spongy tissue that can
expand and contract.

38. Fertilization
● The fusion of male and female gamete is called
fertilization.
● Male gametes are released in the vagina.
● Male gametes swim upwards with the help of the tail.
● Out of the millions of male gametes only a few of them
will reach the upper part of the oviduct.

39. Fertilization
● The rest will die on its way.
● From the ovary egg will be released into the oviduct.
● There fertilization will takes place.
● The head of the male gamete contains the nucleus.
● The head part only penetrates into the egg.
● The nucleus of the male gamete fuses with the nucleus of
the egg.
● This act of fusion is known as fertilization.

40. Implantation
● The fertilized egg is called zygote.
● And it reaches the uterus.
● Before reaches the uterus, a growth of zygote will takes
place.
● A small ball of numerous cells will form.
● It becomes embryo.
● It will get fixed in the walls of uterus.

41. Implantation
● The natural way of fixing of the embryo in the wall of the
uterus is called implantation.
● This produces a state of pregnancy.

42. Fertilization in Humans
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43. Embryo formation
● Growth
● Differentiation
● Growth is the type of irreversible increase in the size and weight of an
individual during the process of development.
● Zygote divides and redivides to form a cluster of cells by cell division.
● Then starts specialisation.
● The specialisation of cells leads to formation of different parts of the
body.
● The whole process is called differentiation.

44. Embryo formation
● Differentiation gives rise to various tissues , organs and organ systems.
● In this way zygote develops into an embryo.
● Embryo soon develops into a baby – Foetus
● At the end of five weeks of pregnancy , the heart and circulatory system
will form.
● After two months, limbs will be produced.

45. Birth
● Gestation
● The full term of the development of an embryo in the uterus is called
gestation.
● In Humans, it lasts for 280 days.
● Baby will come outside through contractions of the muscles of the
uterus.
● Head will comes out first through vagina.