NCERT Solutions for Class 7 Science Chapter 3 Fabric To Fiber

Q.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.

Q.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

Q.3 Which of the following does not yield wool? (i) Yak (ii) Camel (iii) Goat (iv) Woolly dog

Answer :

(iv) woolly dog

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

Answer :

(i) Rearing: The process of keeping, feeding, breeding and medical care of useful animals is called rearing of animals
(ii)Shearing: It is the process of removal of fleece along with a thin layer of skin from the body of sheep.
(iii) Sericulture : Rearing of silkworms to get silk is known as Sericulture.

Q.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, rolling.

Q.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 :

Q.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

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

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

Q.13 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 an egg of a moth

Answer :

Down:
1D. Scour
2D. Silk
3D. Fibre
Across
1A. Wool
2A. Mulberry
3A. Caterpillar