Solution of Chapter 3. Fibre to Fabric (NCERT Science Book)

You must be familiar with the following nursery rhymes:

i. ‘Baa baa black sheep, have you any wool.’

ii. ‘Mary had a little lamb, whose fleece was white as snow.’

Answer the following:

a. Which parts of the black sheep have wool?

b. What is meant by the white fleece of the lamb?

The silkworm is (a) a caterpillar, (b) a larva. Choose the correct option.

(i). a (ii). b (iii) both a and b (iv) neither a nor b.

Which of the following does not yield wool?

(i) Yak (ii) Camel (iii) Goat (iv) Woolly dog.

What is meant by the following terms?

(i) Rearing (ii) Shearing (iii) Sericulture

Given below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.

Shearing, ______, sorting, ______, ___________.

Make sketches of the two stages in the life history of the silk moth which are directly related to the production of the silk.

Out of the following, which are the two terms related to silk production?

Sericulture, floriculture, moriculture, apiculture and silviculture.

Hints: (i) Silk production involves cultivation of mulberry leaves and rearing silkworms.

(ii) Scientific name of mulberry is Morus Alba.

Match the words of Column I with those given in Column II:

Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.

Down

(D)

1. Thorough washing

2. Animal fibre

3. Long thread like structure

Across

(A)

1. Keeps warm

2. Its leaves are eaten by silkworms

3. Hatches from egg of moth

Paheli wants to know the maximum length of continuous silk thread that can be obtained from a cocoon.

Find out for her.

Boojho wants to know why caterpillars need to shed their skin when they grow bigger but we humans do not.

Do you have any idea?

Boojho wants to know why caterpillars should not be collected with bare hands. Can you help him?

Paheli wanted to buy a silk frock and went to the market with her mother. There they found that the artificial (synthetic) silk was much cheaper and wanted to know why. Do you know why? Find out.

Someone told Paheli that an animal called “Vicuna’ also gives wool. Can you tell her where this animal is found? Look for this in a dictionary or an encyclopedia.

When handloom and textile exhibitions are held, certain stalls display real moths of various varieties of silk and their life histories. Try and visit these stalls with elders or teachers and see these moths and stages of their life history.

Look for eggs of any moth or butterfly in your garden or park or any other place full of plants. They look like tiny specks (dots) laid in a cluster on the leaves. Pull out the leaves containing eggs and place them in a cardboard box. Take some leaves of the same plant or another plant of the same variety, chop them and put them in the box. Eggs will hatch into caterpillars, which are busy eating day and night. Add leaves everyday for them to feed upon. Sometimes you may be able to collect the caterpillars. But be careful. Use a paper napkin or a paper to hold a caterpillar.

Observe everyday. Note the (i) number of days taken for eggs to hatch, (ii) number of days taken to reach the cocoon stage, and (iii) number of days to complete life cycle. Record your observations in your notebook.