Solution of Chapter 9. Reproduction in Animals (NCERT Science Exemplar Book)

Sets of reproductive terms are given below. Choose the set that

has an incorrect combination.

In humans, the development of fertilized egg takes place in the

In the list of animals given below, hen is the odd one out.

human being, cow, dog, hen

The reason for this is

Animals exhibiting external fertilization produce a large number of gametes. Pick the appropriate reason from the following.

Reproduction by budding takes place in

Which of the following statements about reproduction in humans is correct?

In human beings, after fertilization, the structure which gets embedded in the wall of the uterus is

Aquatic animals in which fertilization occurs in water are said to be:

After fertilization, the resulting cell which gives rise to a new individual is the

In human beings, the correct sequence of events during reproduction is

Although 2 cells called gametes fuse, the product formed is a single cell called zygote. Justify.

Stages in the lifecycle of silkworm are given below. Write them in sequential order.

pupa, silkworm, egg, silkmoth

What is the importance of reproduction?

In markets, eggs of birds are available but never eggs of dogs. Why?

The eggs of frogs do not have shells for protection, yet they are safe in the water. How?

Fill up the blanks with the terms given below:

body, asexual, binary, single, nucleus

Amoeba is a ___________ celled organism. It reproduces by ___________ reproduction. The process of reproduction begins by the division of its ___________ into two. This is followed by the division of its ___________ into two. This type of reproduction is called ___________ fission.

The term metamorphosis is not used while describing human development. Why?

Mother gives birth to a baby but the baby has characters of both parents. How is this possible?

How is a reproduction in hydra different from that in amoeba?

State whether the following statements are True or False. If false, correct the statement:

(a) External fertilization can occur both in water and on land.

(b) The eggs of fish are covered by hard shells for protection.

(c) The human egg has a head, middle piece, and tail.

(d) In adult human females, a single mature egg is released into an oviduct every month.

Why do only male gametes have a tail?

What does Fig. 9.1 represent?

Observe the figure given as Fig. 9.2 and answer the questions that follow.

(a) Label A and B.

(b) Identify the process.

(c) What happens during this process and what is formed?

How can we say that fish exhibits external fertilization?

After observing Fig. 9.3 answer the following.

a. Read the following statements and label them in the figure:

(i) The part which produces female gametes.

(ii) The part where the development of the baby takes place.

(iii) The part through which the developing embryo passes to reach the uterus.

b. Explain the future development of the embryo that would take place after it gets embedded in the uterus.

Hens and frogs are both oviparous exhibiting different types of fertilization. Explain.

Observe the following figures.

(a)

(b)

(c)

(d)

(i) Identify the stages a to d in Fig. 9.4 during the development of the human baby.

(ii) Arrange the stages in the correct sequence of development.

(iii) Explain the development that takes place in any one stage.