Page 34 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

Making of yarn : 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.
4. Explain in detail the occupational hazards of making fibres from wool and silk.
Ans. Wool industry has a sizeable workforce. However, people employed in the sorting

process, called sorters, run the risk of getting infected with a disease called anthrax
(also known as sorter’s disease). It is a bacterial infection caused by Bacillus anthracis.
This disease is fatal because it can range from skin ulcers with a dark scab to difficulty

in breathing. It mainly affects animals but humans can also get infected through
contact with an infected animal or by inhaling spores. Such risks faced by workers in

any industry are called occupational hazards.
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.
5. What should be included in the diet of sheep to obtain good quality wool?

Ans. Wool-yielding varieties of sheep are reared and bred in different parts of our country.
Shepherds take the herds to graze in the open fields. Sheep are herbivores and eat
grass and leaves. To get good quality wool, pulses, corn, jawar and oil cakes are also

included in their diet. In winter, however, they are kept indoors and fed on leaves,
grain and dry fodder. In India, sheep are reared and bred in Jammu and Kashmir,
states of Himachal Pradesh, Uttaranchal, Sikkim, Arunachal Pradesh, Rajasthan and

Gujarat. After the fleece of a sheep grows thick, it is shaved off to obtain wool.

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