NCERT Solutions for Class 7 Science Chapter 3 Fibre to Fabric

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?

Answer: The hairy skin of black sheep has wool called fleece.

(b) What is meant by the white fleece of the lamb?

Answer: The white coloured hairs of sheep is known as white fleece of the lamb.

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

3. Which of the following does not yield wool?

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

Answer: (iv) Woolly dog

4. What is meant by the following terms?

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

Answer:

• Rearing: The process of bringing up and taking care of livestock like cow, goat, sheep,etc until they are fully grown up is called rearing.
• Shearing: The process in which fleece of sheep is cut off along with thin layer of skin is called shearing.
• Sericulture: Sericulture is rearing of silkworms to obtain silk.

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 of burrs, dying of fibres, making of yarn.

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:

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 cultivation of mulberry leaves and rearing silkworms.(ii) Scientific name of mulberry is Morus alba.

Answer: Sericulture and moriculture.

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

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. [Find figure of puzzle in CBSE textbook ]

Answer:

Down:

• 1D: Thorough washingAnswer: SCOUR
• 2D: Animal fibreAnswer: SILK
• 3D: Long thread like structureAnswer: FIBRE

Across:

• 1A: Keeps warmAnswer: WOOL
• 2A: Its leaves are eaten by silkwormsAnswer: MULBERRY
• 3A: Hatches from egg of mothAnswer: CATERPILLAR

Check other lessons NCERT Solutions for Class 7

Download free NCERT textbook class 7 Science – Chapter 3 Fibre to Fabric