NCERT Solution class 7 Science Chapter-3

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NCERT Solution class 7 Science Chapter-3

Chapter – 3    Fibre to Fabric

Chapter Exercise

Page No. – (32)

 

Q.1- You must be families with the following with the following nursery rhymes:-

  1. ‘Baa baa black sheep, have you any wool.’
  2. ‘Mary had a little lamb, whose fleet was white as snow.’
  3. Which parts of the black sheep have wool?
  4. What is meant by the white fleece of the lamb?

Ans.1- a. The hair skin called fleece has wool in black sheep.

  1. The white fleece of lamb is known hair skin.

 

Q.2- The silkworm is (a) a caterpillar, (b) a larva. Choose the correct option.

  1. a
  2. b
  • both a and b
  1. neither a nor b

Ans.2- iii. Both a and b.

 

Q.3- Which of the following does not yet wool?

  1. Yak
  2. Camel
  • Goat
  1. Woolly Dog

Ans.3- iv. Woolly Dog

 

Q.4- What is meant by following terms?

  1. Rearing
  2. Shearing
  • Sericulture

Ans.4- i. Rearing:- The process of Keeping, Breeding and Medical Care is known as Rearing of animal.

  1. Shearing:- Shearing is a process to removing the fleece of a sheep by a machine.

iii. Sericulture:- The Rearing  of Silkworm to get is known as Sericulture.

 

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

Shearing, ____, sorting, ____, ____, ____.

Ans.5- Shearing, __scouring__, sorting, __picking of burs__, __dying of fibers__, __making of yarn__.

 

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.

Ans.6-

Q.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 rearing silkworms.
  2. Scientific name of mulberry is Morus alba.

Ans.7- i. Sericulture.

  1. Moriculture.

 

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

S. No. Column I S. No. Column II
1. Scouring a. Yields silk fibres
2. Mulberry leaves b. Wood yielding animal
3. Yak c. Food of silk worm
4. Cocoon d. Reeling
    e. Cleaning sheared skin

Ans.8-

S. No. Column I S. No. Column II
1. Scouring e. Cleaning sheared skin
2. Mulberry leaves c. Food of silk worm
3. Yak b. Wood yielding animal
4. Cocoon a. Yields silk fibres
    d. Reeling