Class.7-Science-Chapter.3- FIBRE TO FABRIC

Class.7-Science-Chapter.3- FIBRE TO FABRIC

Exercise Questions

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?

Ans.
a) Wool is obtained from hairy fibres of the sheep.

b) White fleece of the lamb refers to the white colour of their fur.

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.

Ans.
(iii) both a and b

3. Which of the following does not yield wool?

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

Ans.:

The answer is (iv) Woolly dog

4.What is meant by the following terms? (i) Rearing (ii) Shearing (iii) Sericulture

Ans. i) Raising of domestic animals like sheep, goat, yak, cow and buffaloes for commercial purposes such as for milk and fur is known as rearing.

ii) Shearing is a process of removal of animal hair by using machines similar to those used by barbers.

ii) Rearing of silkworms to get silk is known as Sericulture.

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

Shearing, __________, sorting, __________, __________, _________.

Ans.
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.

Ans. Text book diagram.

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

Ans.

Sericulture and moriculture

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

Ans:

Column-I	Column-I
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.

Down

(D) 1 : Thorough washing

2 : Animal fibre

3 : Animal fibre

Across

(A) 1 : Keeps warm

2 : Its leaves are eaten by silkworms

3: Hatches from egg of moth

Ans.:

Down:

1D. Scour

2D. Silk

3D. Fibre

Across

1A. Wool

2A. Mulberry

3A. Caterpillar