NCERT Solutions for Class 7 Science Chapter 3 – Fibre to Fabric
Page No 32:
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) Wool is obtained from the hairy fibres (hair) of the sheep.
(b) White fleece of the lamb refers to the white coloured hair of the lamb.
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?
(i) Rearing (ii) Shearing (iii) Sericulture
Answer:
(i) Rearing: Rearing means helping someone to grow up.
(ii) Shearing: It is the process of removal of fleece along with a thin layer of skin from the body of sheep.
(ii) Sericulture: Sericulture refers to the rearing of silkworms to obtain silk.
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 of burrs__, __dying of fibres__, making of yarn__
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:
The two stages in the life history of silk moth directly related to silk production are
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 cultivation of mulberry leaves and rearing silkworms.
(ii) Scientific name of mulberry is Morus alba.
Answer:
Sericulture and moriculture
Question 8:
Match the words of Column I with those given in Column II:
Column I
|
Column II
| ||
| (i) | Scouring | (a) | Yields silk fibres |
| (ii) | Mulberry leaves | (b) | Wool yielding animal |
| (iii) | Yak | (c) | Food of silk worm |
| (iv) | Cocoon | (d) | Reeling |
| (e) | Cleaning sheared skin |
Answer:
Column I
|
Column II
| ||
| (i) | Scouring | (e) | Cleaning sheared skin |
| (ii) | Mulberry leaves | (c) | Food of silk worm |
| (iii) | Yak | (b) | Wool yielding animal |
| (iv) | Cocoon | (a) | Yields silk fibres |
Page No 33:
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 Across
(D) 1: Thorough washing (A) 1: Keeps warm
2: Animal fibre 2: Its leaves are eaten by silkworms
3: Long thread like structure 3: Hatches from egg of moth
Answer:
