CBSE Class 8 Science Chapter 9 Revision Notes

Chapter 8: Reproduction In Animals Revision Notes

Reproduction is the process through which organisms give birth to their own offspring.


Animals reproduce in two different ways:

(i) Sexual reproduction and(ii) Asexual reproduction


  • Sexual reproduction is the process of combining male and female gametes to produce offspring.

  • The female reproductive organs are the ovaries, oviducts (fallopian tubes), and uterus.

  • Testes, sperm ducts, and the penis are among the male reproductive organs.

  • The ovary generates ova, female gametes, while the testes create sperm, male gametes.

reproductive organsSource

  • Fertilization is the process of combining the ovum with sperm.

  • A zygote is a fertilised egg.

  • Internal fertilisation refers to fertilisation that occurs within the female body. This can be seen in humans and other animals, including hens, cows, and dogs.

  • External fertilisation refers to fertilisation that occurs outside of the female body. This is seen in frogs (in the water), fish, starfish, and other animals.

  • To produce an embryo, the zygote splits several times.

  • For future development, the embryo is implanted in the uterine wall.

  • The foetus is the embryo stage in which all of the body components can be identified.

  • Animals that give birth to offspring, such as humans, cows, and dogs, are viviparous.

  • Oviparous animals lay eggs, such as frogs, lizards, and butterflies.

  • Metamorphosis is the process of a larva growing into an adult through significant changes (moth to a cocoon).


  • Asexual reproduction refers to the process of reproduction in which only one parent is involved.

hydra Source

  • Buds in hydra evolve into new individuals. Budding is the term for this type of asexual reproduction.

  • Amoeba reproduces by separating the nucleus followed by its body into two halves. Binary fission is the name for this sort of asexual reproduction.

Source: Chapter-9.pmd (


Similar Posts