Study Materials

NCERT Solutions for Class 7th Science

 

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Chapter 3. Fibre to Fabric

NCERT Exercise

 

 

 

Exercise:


Q1. 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] Mainly the abdomen and back of the sheep have wool.

[b]White fleece refers to the white hair of lamb that is used to make wool.

 

Q2. 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:

[a] Caterpillar.

Q3. Which of the following does not yield  wool .

(i) Yak (ii) Camel (iii)Goat (iv)wooly dog

Answer:

(iv)wollydog

Q4. What is meant by the following terms?

(i) rearing (ii) Shearing (iii) Sericulture 

Answer:

(i) Rearing: The bringing up and looking after the livestoks and other animals for our commercials benefit is known as rearing.

(ii) Shearing: To obtain wool, the fleece of the sheep along with a thin layer of skin is removed from its body. This process is called shearing.

(iii)sericulture: The rearing of silkworms for obtaining silk is called shearing.

Q5. Given below is a sequence of steps in the processing of wool. Which are the missing steps?

Add them. Shearing, __________, sorting, __________, __________.

Answer:

Scouring,dying,rolling into yarn.

Q6. Make sketches of the two stages in the life history of silk moth which are directly related to the production of silk.

Answer:

 

Q7. Out of the following, which are the two terms related to silk production?

Sericulture, floriculture, moriculture, apiculture and silviculture.

Hints: (i) Hints: Silk production involves cultivation of mulberry leaves and rearing silkworms. (ii) Scientific name of mulberry is Morus alba.

Answer:

Sericulture and moriculture.

Q8. 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 1 Column 2
1.Scouring (e) cleaning sheared skin
2.Mulberry leaves  (c) Food of silkworm
3.Yak (b) Wool yielding animal
4.Cocoon (a) Yeilds silk fibres

Q9. 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

 

 

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