Class 7 Science

Fibre to Fabric

NCERT Solution

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

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

Answer the following question.
(a) Which parts of the black sheep have wool?

Answer: The skin of black sheep has wool.

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

Answer: Fleece means hair of the lamb.

Question 2: The silkworm is (a) caterpillar (b) a larva; choose the correct option.
(i) a (ii) b (iii) both ‘a’ and ‘b’ (iv) neither ‘a’ nor ‘b’

Answer: (b) both 'a' and 'b'


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

(a)Yak
(b) Camel
(c) Goat
(d) Woolly dog

Answer: (d) Woolly dog

Question 4: What is meant by the following terms?

(a) Rearing
(b) Shearing
(c) Sericulture

Answer:
(a) Rearing: Taking care of animals including feeding, grazing, breeding, etc. for meat, and other useful products.
(b) Shearing: The removal of wool from the sheep is called shearing.
(c) Sericulture - The rearing of silkworm for obtaining silk is known as sericulture.



Questions 5: Give below is sequence of steps in the processing of wool. Which are the missing steps? Add them.
Shearing _________ Sorting _________ _______________.

Answer: Shearing Scouring Sorting Colouring Spinning

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:

stages of life cycle of silk moth



Question7: Out of the following which are the two terms related to silk production?

a. Sericulture
b. Floriculture
c. Moriculture
d. Apiculture and
e. Silviculture

Answer: (a) Sericulture and (b) Moriculture are related to silk production.

Question 8: Match the following

Column IColumn 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: 1 – (e), 2 – (c), 3 – (b), 4 – (a)