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Living Science Solutions for Class 7 Science Chapter 4 - Animal Fibres

Living Science Solutions for Class 7 Science Chapter 4 Animal Fibres are provided here with simple step-by-step explanations. These solutions for Animal Fibres are extremely popular among class 7 students for Science Animal Fibres Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Living Science Book of class 7 Science Chapter 4 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Living Science Solutions. All Living Science Solutions for class 7 Science are prepared by experts and are 100% accurate.

Page No 42:

Question 1:

Name the source from which the following are obtained:

(a) silk
(b) wool
(c) angora

Answer:

(a) Silk is obtained from a silkworm.
(b) Wool is obtained from a sheep.
(c) Angora is obtained from an Angora rabbit.

Page No 42:

Question 2:

Which complex compounds are animal fibres made up of?

Answer:

Proteins are the complex compounds that make up animal fibres.

Page No 42:

Question 3:

Which material forms the base of vegetable fibres?

Answer:

Cellulose forms the base of all vegetable fibres.

Page No 42:

Question 4:

The removal of wool from a sheep is called _______

Answer:

The removal of wool from a sheep is called shearing.

Page No 42:

Question 5:

___________ is the management and breeding of silkworms for the production of silk.

Answer:

Sericulture is the management and breeding of silkworms for the production of silk.

Page No 42:

Question 6:

Wool traps more air than cotton. True of false?

Answer:

True.
Wool can trap more air because of the air spaces present in its fibres.



Page No 43:

Question 4:

Which of these fabrics traps air the most−silk, wool or cotton? What is the effect of this on the porperty of the fabric made from this fibre?

Answer:

Wool fabric can trap most of the air. This property of the fabric helps it to prevent heat from escaping. Because air is a bad conductor of heat, the body heat cannot escape. Thus, the fabric helps in keeping our body warm and protecting us from the harsh cold.

Page No 43:

Question 5:

Mention the steps in silk production.

Answer:

Steps involved in silk production are as follows:

  • The first step is to collect the cocoons and kill the insect inside them. For this, the cocoons are either boiled, steamed or treated in an oven.
  • The next step is reeling or filature. It is a delicate process of extracting silk fibres from the treated cocoons. In the next step, these fibres are then spun into threads.
  • These silk threads are then used to weave silk clothes.

Page No 43:

Question 6:

What adverse effects are observed on health of workers in the silk industry?

Answer:

Those working in the silk industry are prone to respiratory diseases, scabies or other skin infections.
The vapour produced during the steaming, cooking and reeling of cocoons, if inhaled, can cause asthma, respiratory problems or bronchial ailments. During reeling, the workers need to boil the cocoons in warm water. Because of the regular dipping of hands into the warm or boiling water, their skin develops blisters, and later starts peeling-off.

Page No 43:

Question 1:

Why is sheep shearing not done during the cold season?

Answer:

Sheep shearing is avoided in the winters so as to allow the sheep to keep itself warm with its thick coat of hair. This wooly coat protects the sheep from the harsh winter conditions. In summers, sheep need to keep their body cool and no more need the thick coat of wool. Thus, shearing is done in the summers and not in the winters. 

Page No 43:

Question 2:

Does shearing hurt the sheep?

Answer:

No, shearing does not hurt the sheep. Shearing is the process of shaving the thick coat of wool from the sheep's skin. Since, hair is a dead tissue, its shaving does not hurt the sheep.

Page No 43:

Question 3:

Animal activists oppose the present process of getting silk from the cocoon. Why do you think they are against it?

Answer:

The present process of extracting silk from the cocoons involves boiling and killing of cocoons. For obtaining 1 kg of silk, 5500 silkworms are killed. Animal activists are against this process, as it involves the killing of silkworms on a large scale.



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