In this article, discuss the notes of the Chapter Reproduction in Animals of Class 8 CBSE Board with detailed explanation with help of point, Class 8 Chapter 9 Reproduction in Animals Notes PDFs.
Reproduction in Animals Notes
1. There are two modes by which animals reproduce. These are: (i) Sexual reproduction, and
(ii) Asexual reproduction
2. Reproduction resulting from the fusion of male and female gametes is called sexual reproduction.
3. The reproductive organs in the female include ovaries, oviducts and uterus.
4. The reproductive organs in males include the testes, sperm ducts and penis.
5. The ovary produces female gametes called ova and the testes produce male gametes called sperms.
6. The fusion of the ovum and sperm is called fertilization. The fertilized egg is called a zygote.
7. Fertilization that takes place inside the female body is called internal fertilization. This is observed in human beings and other animals such as hens, cows and dogs.
8. Fertilization that takes place outside the female body is called external fertilization. This is observed in frogs, fish, starfish, etc.
9. The zygote divides repeatedly to give rise to an embryo.
10. The embryo gets embedded in the wall of the uterus for further development.
11. The stage of the embryo in which all the body parts are identifiable is called a foetus.
12. Animals such as human beings, cows and dogs which give birth to young ones are called viviparous animals.
13. Oviparous Animals: Animals that lay eggs are called oviparous animals, e.g., frogs, lizards, butterflies, etc.
14. Animals such as hen, frog, lizard and butterfly which lay eggs are called oviparous animals.
15. The transformation of the larva into an adult through drastic changes is called metamorphosis.
16. The type of reproduction in which only a single parent is involved is called asexual reproduction.
17. In hydra, new individuals develop from buds. This method of asexual reproduction is called budding.
18. Amoeba reproduces by dividing themselves into two. This type of asexual reproduction is called binary fission.