NCERT Solutions for Class-7 Science Chapter-3 Fibre to Fabric

NCERT TEXTBOOK EXERCISES

Question 1. 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?
Answer:
(a) The hairy skin - called fleece, has wool in black sheep.
(b) White fleece means hairy skin which is white in colour.

Question 2. 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)
Answer:
(iii) both (a) and (b)

Question 3. Which of the following does not yield wool?
(i) Yak
(ii) Camel
(iii) Goat
(iv) Woolly dog
Answer:
(iv) Woolly dog

Question 4. What is meant by the following terms?
1. Rearing
2. Shearing
3. Sericulture
Answer:
1. Rearing: Bringing up and looking after the sheep is called rearing.
2. Shearing: To obtain wool, the fleece of the sheep along with a thin layer of skin is removed from its body. This process is called shearing.
3. Sericulture: The rearing of silkworms for obtaining silk is called sericulture.

Question 5. Given below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.
Shearing, ……., sorting ………, ………., ……….
Answer: Shearing, scouring, sorting, picking out burrs, colouring, rolling.

Question 6. Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.
Answer:

Question 7. Out of the following, which are the two terms related to silk production?
Sericulture, floriculture, moriculture, apiculture and silviculture.
Hints:
(i) Silk production involves the cultivation of mulberry leaves and rearing silkworms.
(ii) Scientific name of mulberry is Morus alba.
Answer: Sericulture, Moriculture.

Question 8. Match the words of Column I with those given in Column II:

Column I	Column II
1. Scouring	(a) Yields silk fibres
2. Mulberry leaves	(b) Wool yielding animal
3. Yak	(c) Food of silkworm
4. Cocoon	(d) Reeling
	(e) Cleaning sheared skin

Answer:

Column I	Column II
1. Scouring	(e) Cleaning sheared skin
2. Mulberry leaves	(c) Food of silkworm
3. Yak	(b) Wool yielding animal
4. Cocoon	(a) Yields silk fibres

Question 9. 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
Answer: