ALLSOL

NCERT Solutions for Class 8 Science Chapter 9 Reproduction in Animals

NCERT Solutions for Class 8 Science Chapter 9 Reproduction in Animals

Exercises

Question :- 1. Explain the importance of reproduction in organisms.

Answer:-  Reproduction is a biological process through which organisms give birth to their off springs. It helps in maintaining the continuity and increasing the population of a particular species.

Question :- 2. Describe the process of fertilisation in human beings.

Answer:-  The fusion of male gametes “Sperms” with the female gametes “Ova”  is called fertilization.  This results in the formation of a fertilised egg or zygote

Question :- 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.

Answer:- (i) in female body.

(b) A tadpole develops into an adult frog by the process of

(i) fertilisation (ii) metamorphosis (iii) embedding (iv) budding

Answer:-  (ii) metamorphosis

(c) The number of nuclei present in a zygote is

(i) none (ii) one (iii) two (iv) four

Answer:-  (ii) one

Question :- 4. Indicate whether the following statements are True (T) or False (F).

  • (a) Oviparous animals give birth to young ones. ( )
  • (b) Each sperm is a single cell. ( )
  • (c) External fertilisation takes place in frog. ( )
  • (d) A new human individual develops from a cell called gamete. ( )
  • (e) Egg laid after fertilisation is made up of a single cell. ( )
  • (f) Amoeba reproduces by budding. ( )
  • (g) Fertilisation is necessary even in asexual reproduction. ( )
  • (h) Binary fission is a method of asexual reproduction. ( )
  • (i) A zygote is formed as a result of fertilisation. ( )
  • (j) An embryo is made up of a single cell. ( )

Answer:-

  • (a) False
  • (b) True
  • (c) True
  • (d) False
  • (e) True
  • (f) False
  • (g) False
  • (h) True
  • (i) True
  • (j) False

 

Question :- 5. Give two differences between a zygote and a foetus.

Answer:- 

Zygote

Foetus

It is a Unicellular, i.e. it contains only one cell

It is a Multicellular, i.e. it contains many cell

It is formed when a male gamete or sperm and a female gamete or ova fuse together.

It is formed by the zygote’s repeated division.

Question :- 6. Define asexual reproduction. Describe two methods of asexual reproduction in animals.

Answer:- Asexual reproduction means the process of reproduction in which only one parent is involved.  There are mainly two methods of asexual reproduction:-

(i) Binary fission: In binary fission, a single parent cell is divided into two equal individual cells. It occurs in Amoeba.

(ii) Budding: Budding occurs when an organism develops a bulge known as bud, which develops into an adult organism and separates from the parent body to live a life of its own. It occurs in Hydra.

Class 8 Science Chapter 9 Reproduction in Animals Question 6 Answer
NCERT Solutions for Class 8 Science Chapter 9 Reproduction in Animals Question 6 Answer

Question :- 7. In which female reproductive organ does the embryo get embedded?

Answer:- Uterus

 

Question :- 8. What is metamorphosis? Give examples.

Answer:- The transformation of the larva into adult through drastic changes is called metamorphosis. For example it occurs in frog and butterfly.

 

Question :- 9. Differentiate between internal fertilisation and external fertilisation.

Answer:-

Internal Fertilisation

External Fertilisation

It occurs inside the female body.

It occurs outside the female body.

Offsprings have a high chance of survival.

Offsprings have a low chance of survival.

The females lay either fertilised eggs or a fully grown young one.

The females lay unfertilised eggs

Examples are  humans, dogs, cows etc.

Examples are fish and frogs etc.

 

Question :- 10. Complete the crossword puzzle using the hints given below.

Across

  1. The process of the fusion of the gametes.
  2. The type of fertilisation in hen.
  3. The term used for bulges observed on the sides of the body of hydra.
  4. Eggs are produced here.

Down

  1. Sperms are produced in these male reproductive organs.
  2. Another term for in vitro fertilisation.
  3. These animals lay eggs.
  4. A type of fission in amoeba.
NCERT Solutions for Class 8 Science Chapter 9 Reproduction in Animals
NCERT Solutions for Class 8 Science Chapter 9 Reproduction in Animals Question 10 answer