NCERT Solutions Class 8 Science Chapter 9 Reproduction In Animals
NCERT Solutions Class 8 Science Chapter 9 Reproduction In Animals: National Council of Educational Research and Training Class 8 Science Chapter 9 Solutions – Reproduction In Animals. NCERT Solutions Class 8 Science Chapter 9 PDF Download.
NCERT Solutions Class 8 Science Chapter 9: Overview
|
Board |
NCERT |
| Class |
8 |
|
Subject |
Science |
| Chapter |
9 |
|
Chapter Name |
Reproduction In Animals |
| Topic |
Exercise Solutions |
NCERT Solutions Class 8 Science Chapter 9 – Reproduction In Animals
CHAPTER: – 9
(REPRODUCTION IN ANIMALS)
Exercise: –
1)Explain the importance of reproduction in organisms.
Ans: – The reproduction process in organisms is the reason for the remain in the environment. These organisms increase their population by this process. Reproduction happened throughout the various way in organisms like sexual reproduction or asexual reproduction.
2)Describe the process of fertilisation in human beings.
Ans: – The process of fertilization in human being happen in the female body. The sperm from the male body and ovum from the female body after mixing create the egg or zygote which after fertilization prepare the single cell from which the complete cell produce.
3)Choose the most appropriate answer.
(a) Internal fertilisation occurs
(i) in female body.
(ii) outside female body.
(iii) in male body.
(iv) outside male body.
Ans: – Option(i).
Explanation– female ovary the fertilization happens.
(b) A tadpole develops into an adult frog by the process of
(i) fertilisation (ii) metamorphosis (iii) embedding (iv) budding.
Ans: – Option(ii).
Explanation– (The way through the complete frog grows from tadpoles is known as metamorphosis)
(c) The number of nuclei present in a zygote is
(i) none (ii) one (iii) two (iv) four.
Ans: – Option(ii).
Explanation- (When one sperm unites and one eggs from ovaries meet one zygote form and then complete cell made)
4) Indicate whether the following statements are True (T) or False (F).
(a) Oviparous animals give birth to young ones.
Ans: – False.
Explanation- (For example, man is like oviparous as young one came from mother body)
(b) Each sperm is a single cell.
Ans: – True.
Explanation- (For this single zygote is formed)
(c) External fertilisation takes place in frog.
Ans: – True.
Explanation– (Through metamorphosis process frog grows)
(d) A new human individual develops from a cell called gamete.
Ans: – False.
Explanation– (This known as zygote)
(e) Egg laid after fertilisation is made up of a single cell.
Ans: – True.
Explanation– (As a result, from only one zygote complete cell form)
(f) reproduces by budding.
Ans: – False.
Explanation– (This is asexual reproduction)
(g) Fertilisation is necessary even in asexual reproduction.
Ans: – False.
Explanation– (In this case reproduction happen outside of the cell through various process)
(h) Binary fission is a method of asexual reproduction.
Ans: – True.
Explanation– (This process happens outside of the body)
(i) zygote is formed as a result of fertilisation.
Ans: – True.
Explanation– (Male sperm and female eggs are fertilized after meeting)
(j)An embryo is made up of a single cell.
Ans: – False.
Explanation– (Embryo is multicellular)
5) Give two differences between a zygote and a foetus.
Ans: –
| Zygote | Foetus |
| It is a Single cell. | It is a Multicellular |
| Male and female gametes after fusion create zygote. | Zygote after division create foetus. |
6)Define asexual reproduction. Describe two methods of asexual reproduction in animals.
Ans: – The asexual reproduction is the process of reproduction in which the sexual activity happens in the outside of the cell.
The method of asexual reproduction is
Budding: – The bud is formed outside the parent cell and from there when it detached the new body is formed.
Binary fission:- The animal body after division of the parents’ nucleus forms a new organism.
7)In which female reproductive organ does the embryo get embedded?
Ans: – In the wall of the uterus of the female body the embryo gets embedded. And after that a new cell is brought up.
8)What is metamorphosis? Give examples.
Ans: – Some of the organisms from with the larva so, the process in which a new body is formed from the larva is known as metamorphosis process. In the outside of the body from larva a complete cell form.
Example: – Frog.
9)Differentiate between internal fertilisation and external fertilisation.
Ans: –
| Internal fertilization |
External fertilization |
| This fertilization happens inside the body. | This fertilization happens outside the body. |
| Fertilized egg is produced | Unfertilized egg is produced. |
| Example: – Human being | Example: – Frog |
10) Complete the crossword puzzle using the hints given below.
Across
- The process of the fusion of the gametes.
- The type of fertilisation in hen.
- The term used for bulges observed on the sides of the body of hydra.
- Eggs are produced here.
Down
- Sperms are produced in these male reproductive organs.
- Another term for in vitro fertilisation.
- These animals lay eggs.
- A type of fission in amoeba.
Ans: –
