NCERT SOLUTIONS- REPRODUCTION IN ANMIALS- CHAPTER 9

Q- Explain the importance of reproduction in organisms?

Ans- Reproduction is very important for the organisms because it ensures the continuity of species generation after generation.

Q- Describe the process of fertilisation in human beings?

Ans- The first step in the process of reproduction is the fusion of a sperm and an ovum. For this to happen, million of sperms from the male are transferred into the female body. The sperms swim upto the oviduct with the help of their tails and reach the egg. When they come in contact with the egg, one of the sperm may fuse with the egg. Such fusion of the egg and sperm is called fertisation. During fertilisation , the nuclei of the sperm and the egg fuse to form a single nucleus.This results in the formation of egg or zygote.

Q- Differentiate between zygote and a foetus?

Ans-   Zygote                                                                                                 foetus

It is single celled.                                                                             It is multicellular.
Zygote  is formed by the fusion                                                        foetus is formed by the repeated
of male and female gametes                                                             division of embryo and differentiation.

Q- Define asexual reproduction. Describe two methods of asexual reproduction in animals?

Ans- The type of reproduction in which only one single parent is involved is called asexual reproduction. Asexual reproduction may occur in many ways-

By budding- In hydra new individuals develop from buds. This process of asexual reproduction is called budding.

By binary fission- Amoeba reproduces by simply dividing itself into two. This type of asexual reproduction is called binary fission.

Q- In which type of female reproductive organ does the embryo get embedded.?

Ans- Uterus

Q- What is metamorphosis ? Give examples?

Ans- The drastic change that transforms a larva into  an adult is called metamorphosis. Egs- frog, silkworm, honeybee etc.

Q- Differentiate  between internal fertilisation and external fertilisation?

Internal fertilisation                            

Takes place inside the body of the female.                                  Takes place outside the body of the female.
Female lays either fertilized eggs or a complete                             female lays unfertilized egg.
individual is born.