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

Fibre to Fabric

Question 1.
You must be familiar with the following nursery rhymes:

1.  ‘Baa baa black sheep, have you any wool.’
2. ‘Mary had a little lamb, whose fleece was white as snow.’

(a) Which parts of the black sheep have wool?
(b) What is meant by the white fleece of the lamb?

Solution:
(a) Mainly the abdomen and back of the sheep have wool.
(b) White fleece refers to the white hair of lamb that is used to make wool.

Question 2.
The silkworm is
(a) a caterpillar
(b) a larva
Choose the correct option :

1. a
2. b
3. both a and b
4. neither a nor b

Solution:
1. a caterpillar.

Question 3.
Which of the following does not yield wool?

1. Yak
2. Camel
3. Goat
4. Woolly dog

Solution:
4.  Woolly dog.

Question 4.
What is meant by the following terms?

1. Rearing
2. Shearing
3. Sericulture

Solution:

1.  Rearing :
   The 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, …………, …………, ………… .

Solution:
Scouring, picking out of 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.

Solution:

Question 7.
Out of the following, which are the two terms related to silk production? Sericulture, floriculture, moriculture, apiculture and silviculture.
Hints :

1. Silk production involves cultivation of mulberry leaves and reàring silkworms
2. Scientific name of mulberry is Morus alba.

Solution:
Sericulture and moriculture.

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

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

Solution:
(l)-(e)
(2)-(c)
(3)-(b)
(4)-(a)

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

Solution: