Reproduction in Animals

Reproduction in Animals is a chapter given in the book prescribed in CBSE schools like Podar International Schools in India based on the NCERT Book for class 8.
Here, you can find the question and answers given in the book "Science Matters" by Shikshan Publication.

Reproduction in Animals: Science Matters Book Questions and Answers

Let Us Exercise (Reproduction in Animals)

1. Choose the correct option from the following.

a. ________ reproduce by fragmentation.
(i) Paramecium and starfish
(ii) Paramecium and planaria
(iii) Planaria and starfish
(iv) Starfish and flatworm

(iii) Planaria and starfish reproduce by fragmentation.

b. The pathway of sperm after entering the female reproductive system is:
(i) Cervix ⇾ Vagina ⇾ Uterus ⇾ Oviduct
(ii) Vagina ⇾ Cervix ⇾ Uterus ⇾ Oviduct
(iii) Uterus ⇾ Cervix ⇾ Vagina ⇾ Oviduct
(iv) Oviduct ⇾ Vagina ⇾ Cervix ⇾ Uterus

(ii) Vagina ⇾ Cervix ⇾ Uterus ⇾ Oviduct

c. Which of the following is an oviparous animal?
(i) Cat
(ii) Rat
(iii) Dog
(iv) Turtle

(iv) Turtle is an oviparous animal.

d. It takes about __________ for a human embryo to develop into a foetus.
(i) 4 weeks
(ii) 16 weeks
(iii) 8 weeks
(iv) 20 weeks

(iii) It takes about 8 weeks for a human embryo to develop into a foetus.

2. Assertion-Reasoning questions.

For questions (i) and (ii), two statements are given—one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:

(a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of the Assertion (A).
(b) Both Assertion (A) and Reason (R) are true, and Reason (R) is not the correct explanation of the Assertion (A).
(c) Assertion (A) is true, but Reason (R) is false.
(d) Assertion (A) is false, but Reason (R) is true.

(i) Assertion (A): An enzyme is secreted from the head region of a sperm during fertilization.
Reasonn (R): The enzyme secreted by sperms easily digests the jelly coat of an ovum so that the nucleus of the sperm can fuse with the nucleus of the ovum.

(a) As an enzyme is secreted from the head region of a sperm to digest the jelly coat of an ovum. So, Reason (R) is the correct explanation of Assertion (A).

(ii) Assertion (A): The scrotum is present outside the abdominal cavity.
Reasonn (R): The scrotum helps to maintain the testes at an elevated temperature.

(c) Assertion A is correct as the scrotum is present outside the abdominal cavity. But Reason (R) is incorrect, as the scrotum helps in lowering the body temperature and not in elevating the body temperature.

3. Answer the following questions in one sentence.

a. Define the term reproduction.

Reproduction is a process by which organisms produce offspring of their own kind.

b. What is semen?

Semen is a mixture of sperm and secretions of seminal vesicles, the prostate gland, and Cowper's glands.

c. State one difference between binary fission and budding.

One difference between binary fission and budding:

Binary FissionBudding
It involves the division of a parent organsim into two identical daughter cells.It involves small outgrowths or bulges called buds due to repeated cell division.

d. What is the process of specialisation of cells to form organs and organ systems of the body called?

The process of specialisation of cells to form organs and organ systems of the body is called cell differentiation.

4. Answer the following questions in 2-3 sentences.

a. State two similarities between estrogen and progesterone with respect to their functions.

The two similarities between estrogen and progesterone with respect to their functions are
(i) Both hormones regulate the changes observed in the female body, such as breast development and widening of hips.
(ii) Both hormones help to maintain the uterus lining for implantation of embryo.

b. Many eggs need to be fertilised in organisms that have adapted for external fertilisation. Give two reasons to show the importance of this characteristic in the continuation of their species.

Many eggs need to be fertilised in organisms that have adapted for external fertilisation, because of the following two reasons.
(i) Most of the fertilised eggs may get washed away as it happens in water.
(ii) Most of the eggs are eaten up by the predators.

c. What is asexual reproduction? Why do buds develop on the body of a hydra?

A type of reproduction where offspring are produced from a single parent without the fusion of sex cells is known as asexual reproduction.
Buds develop on the body of a hydra due to repeated cell division.

4. Answer the following questions in 3-5 sentences.

a. List any three advantages of asexual reproduction.

The three advantages of asexual reproduction are:
(i) Only one parent is needed.
(ii) No gametes (sex cells) are involved.
(iii) All characteristics are passed on to the offspring.

b. Which organ in the human male reproductive system is also a part of the urinary system? Where is this organ located? State its function in both the organ systems.

Urethra in the human male reproductive system is also a part of the urinary system. This organ is located in penis.
The urethra carries sperm as a part of the reproductive system and urine as a part of the urinary system.

Science Matters Class 8 Questions and Answers

Chapter 3: Combustion and Flame

Extra Questions on Reproduction in Animals, Class 8

1. Choose the correct option from the following.

(a) Which of the following modes of reproduction is asexual?
(i) Binary Fission
(ii) Budding
(iii) Fragmentation
(iv) All of the above

(iv) Binary fission, budding, and fragmentation are all modes of asexual reproduction.

(b) In which of the following modes of reproduction does a new organism develop from parts of the parent body?
(i) Binary Fission
(ii) Budding
(iii) Fragmentation
(iv) None of these

(iii) Fragmentation is a type of reproduction in which a new organism develops from parts or fragments of the parent body.

(c) In which of the following modes of reproduction do small outgrowths or bulges develop on the body of the parent organism due to repeated cell division?
(i) Binary Fission
(ii) Budding
(iii) Fragmentation
(iv) None of these

(ii) Budding is a type of reproduction in which small outgrowths or bulges develop on the body of the parent organism due to repeated cell division.

(d) Which of the following modes of reproduction involves the division of a parent organism into two identical daughter cells?
(i) Binary Fission
(ii) Budding
(iii) Fragmentation
(iv) None of these

(i) Binary fission involves the division of a parent organism into two identical daughter cells.

(e) Which of the following modes of reproduction involves the division of a parent organism into two identical daughter cells?
(i) Binary Fission
(ii) Budding
(iii) Fragmentation
(iv) None of these

(i) Binary fission involves the division of a parent organism into two identical daughter cells.

(f) Which of the following is another name of gametes?
(i) sex cells
(ii) foetus
(iii) zygote
(iv) embryo

(i) Another name of gametes is sex cells.

(g) Which of the following parts of the male reproductive organ produces the male sex hormone testosterone?
(i) Prostate gland
(ii) Cowper's glands
(iii) Urethra
(iv) Testes

(iv) Testes produce the male sex hormone testosterone.

(h) Which part of the female reproductive system is called the womb?
(i) Ovaries
(ii) Oviducts
(iii) Uterus
(iv) Vagina

(iii) The uterus is also known as womb.

(h) In which part of the female reproductive system does fertilization take place?
(i) Ovaries
(ii) Oviducts
(iii) Uterus
(iv) Vagina

(ii) Fertilisation takes place in the oviducts or fallopian tubes of the female.

(i) In which part of the female reproductive system does the development of a baby take place?
(i) Ovaries
(ii) Oviducts
(iii) Uterus
(iv) Vagina

(iii) Development from embryo to foetus to baby takes place in the uterus.

3. Answer the following questions.

a. Define asexual reproduction.

Asexual reproduction is a type of reproduction where offspring are produced from a single parent without the fusion of sex cells.

b. In which mode of reproduction are the offspring identical to each other? And why?

The offspring are identical to each other, both physically as well as genetically, in asexual mode of reproduction. This is so because only one parent is involved in the reproduction process.

c. What is sexual reproduction?

Sexual reproduction is a type of reproduction where new organisms are formed by the fusion of male and female gametes.

d. What is fertilisation?

The process of fusion of a male gamete with a female gamete to produce a single-celled zygote is called fertilisation.

e. Write two disadvantages of sexual reproduction.

Two disadvantages of sexual reproduction are:
1. Two parents are involved. It cannot be done by a single parent.
2. Slower process than asexual mode of reproduction.

f. Write the different parts of the male reproductive system.

The male reproductive system in human beings includes:
-- a pair of testes (main reproductive organ)
-- ducts (epididymis, sperm ducts or vas deferens and urethra)
-- accessory reproductive organs (penis, seminal vesicles, prostate gland, and Cowper's glands)

g. What are the differences between asexual and sexual reproduction.

Difference between asexual and sexual reproduction.

Criteria Asexual reproduction Sexual reproduction
Number of parents.One parent is needed.Two parents are needed.
Level of genetic similarityOffspring is genetically
similar to the parent.		Offspring is genetically
different from the parent.
Number of offspringA larger number of
offspring are produced.		Usually, a limited number of
offspring are produced.
Time taken to produce
offspring		It is a faster process.It is a slower process.