Page 28 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

v The silk fibres thus obtained are drawn and rolled into silk threads or yarn. The silk yarn is

used by weavers to weave silk cloth.
v People employed in the silk industry run a risk of getting infected with diseases, such as

respiratory diseases, scabies and other skin infections. While boiling cocoons in water,
workers remain in contact with the boiling water due to which their skin becomes raw,
develops blisters and begins to peel off. Some also suffer from respiratory problems from the

vapours produced while reeling or steaming the cocoons. This leads to bronchial ailments
and asthma.

Exercise

A. Tick (3) the correct answer.
1. Which of the following is not a type of silk?

(a) Mulberry silk (b) Tassar silk (c) Muga silk (d) Moth silk
Ans. (d)

2. Silk fibre is obtained from the ...................... .

(a) Fleece of sheep (b) Cotton ball (c) Cocoon (d) Shiny jute stalk
Ans. (c)

3. The general process that takes place at a sheep shearing shed is ...................... .
(a) Removal of fleece

(b) Rolling of sheep fibre into yarn

(c) Washing of sheep fibre to remove grease
(d) Separating hair of different textures

Ans. (a)

4. Silkworms secrete fibre made of ...................... .
(a) Fat (b) Cellulose (c) Protein (d) Nylon

Ans. (c)

5. Yak wool is common in...................... .
(a) Tibet (b) Ladakh (c) Both (a) and (b) (d) None of these

Ans. (c)
6. Which of the following is NOT a plant fibre?

(a) Flax (b) Silk (c) Hemp (d) Jute

Ans. (b)
7. Which country is the largest silk producing country in the world?

(a) China (b) India (c) Bangladesh (d) Japan
Ans. (a)

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