NCERT Solutions Class 7 Science Chapter 3 Fibre to Fabric

NCERT Solutions for Class 7 Science for chapter 3 Fibre to Fabric

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 fleece (hair) of sheep.
(b) White fleece refers to white thick hairy coat of 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.

The correct option is (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: Bringing up and looking after farm animals are known as rearing.

(ii) Shearing: The process of removing the fleece of sheep along with a thin layer of skin is called shearing.

(iii) Sericulture: Rearing (raising) of silkworms for producing silk is known as sericulture.

 

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

Shearing, ____________. sorting ________

Answer.

Shearing, scouring, sorting, drying, carding

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.

 

Question.7 - Out of the following, which are the two terms related to silk production?

Sericulture, floriculture, moriculture, apiculture and silviculture.

Hint: (i) Silk production involves cultivation of mulberry leaves and rearing silkworms.

(ii) Scientific name of mulberry is Morus alba.

Answer.

Out of the given, terms related to silk production are sericulture and moriculture.

Note:

Sericulture: Rearing of silkworms for the production of silk is known as sericulture.

Moriculture: Science of mulberry plant cultivation is known as moriculture.

 

Question.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 silk worm
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 silk worm
3. Yak                                        (b) Wool yielding animal
4. Cocoon                                   (a) Yields silk fibres

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

Answer