3. Fibre to Fabric Science class 7 in English Medium ncert book solutions Long Answered Questions

Long Answered Questions: 

Ques1: Name the animals those yield wool?
Ans: (i) Angora goat

(ii) Goat

(iii) Sheep

(iv) Camel

(v) yak

(vi) Llama

(vii) Alpaca 

Ques8: Write the steps of obtaining wool. 
Ans: There are six steps of obtaining wool. 

(i) Shearing: The fleece of the sheep along with a thin layer of skin is removed from its body. This process is called shearing. In this process the hairs are shaved off. The hair provide woolen fibres.

(ii) Scouring : The sheared skin with hair thoroughly washed in tanks to remove grease, dust and dirt. This is called scouring.

(iii) Sorting: The hairy skin is sent to a factory where hair of different textures are separated. This ia called sorting.

(iv) Cleaning of Burrs: The small fluffy fibres, called burrs, are picked out from the hair. The fibres are scoured again and dried. This is the wool ready to be drawn into fibres.

(v) Dyeing : The dyeing in various colours. as the natural fleece of sheep and goats is black, brown or white.

(vi) Rolling into Yarn : The fibres are straightened, combed and rolled into yarn. The longer fibres are made into wool for sweaters and the shorter fibres are spun and woven into woollen cloth.

Ques3: write the life history of the silk moth.
Ans: The female silk moth lays eggs, from which hatch larvae which are called caterpillars or silkworm. They grow into pupa. It first weaves a net to hold itself is known as cocoon. Then they swing and move during these movement they secrete fibre made of a protein which hardens on exposure to air and becomes silk fibre. 

Ques4: Make sketches of the life history of the silk moth. 
Ans: