Active Science Solutions for Class 7 Science Chapter 3 Fibres, Fabric And Clothing are provided here with simple step-by-step explanations. These solutions for Fibres, Fabric And Clothing are extremely popular among class 7 students for Science Fibres, Fabric And Clothing Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Active Science Book of class 7 Science Chapter 3 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Active Science Solutions. All Active Science Solutions for class 7 Science are prepared by experts and are 100% accurate.

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Question 1:

The silkworm is a _______________
(a) caterpillar
(b) egg laid by the moth
(c) larva
(d) worm

Answer:

(a) caterpillar
The silkworm is a caterpillar.

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Question 2:

The following are the steps involved in the processing of wool fibres.
A. The fibres are washed to remove dirt and then dried.
B. The fleece of the sheep is removed.
C. The woollen yarn is then dyed in various colours.
D. The fibres are then combed to straighten them.
E. The fibres are then spun into yarn.
F. The fleece is then sorted according to texture and quality.

The correct sequence in which this process takes place is ____________________  
(a) B, A, E, D, F, C
(b) C, E, D, F, A, B
(c) A, B, F, D, E, C
(d) B, A, F, D, E, C

Answer:

(d) B, A, F, D, E, C

The fleece of the sheep is removed. The fibres are washed to remove dirt and then dried. The fleece is then sorted according to texture and quality. The fibres are then combed to straighten them. The fibres are then spun into yarn. The woollen yarn is then dyed in various colours.

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Question 3:

Raghu took out a torn shirt. He pulled out a few strands called 'X' from his shirt. When he untwisted them, he found very thin strands called 'Y'. Identify 'X' and 'Y'.
(a) X-yarn, Y-fibre
(b) X-fibre, Y-yarn
(c) X-fabric, Y-yarn
(d) X-fleece, Y-yarn

Answer:

(a) X-yarn, Y-fibre

Fabric (or cloth) is made of yarns, which in turn are made of fibres. Raghu pulled out a few strands called yarns from his shirt. When he untwisted them, he found very thin strands called fibres.

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Question 4:

The resting stage of the caterpillar is
(a) larva.
(b) moulting.
(c) pupa.
(d) adult moth.

Answer:

(c) pupa
The resting stage of the caterpillar is pupa.



Page No 31:

Question 5:

Identify the picture: A and B
Figure

(a) A-a tiny caterpillar hatching out of its egg; B- the pupa stage
(b) A-the pupa changing into a moth; B-the caterpillar eating mulberry leaves
(c) A-caterpillar completely covering itself with silk; B-the caterpillar eating mulberry leaves
(d) A-taking out threads from the cocoon; B-the resting stage of the caterpillar

Answer:

(c) A-caterpillar completely covering itself with silk; B-the caterpillar eating mulberry leaves

A female moth lays eggs. These eggs hatch into larvae called caterpillars. The caterpillars eat mulberry leaves constantly for four to six weeks as shown in figure B. A caterpillar moults many times by casting off its old skin, after which it stops growing. Then, it spins a white silk cocoon around itself as shown in figure A.

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Question 6:

Moulting is
(a) the resting stage in the lifecycle of a silkworm.
(b) the change in appearance during the different stages in the life cycle of a silkworm.
(c) the process of spinning of cocoon.
(d) the process of casting off old skin.

Answer:

(d) the process of casting off old skin.

Moulting is the process of casting off old skin.

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Question 7:

Match the items in column I to those in column II.

Column I Column II
a. shearing i. cleaning wool
b. sericulture ii. changing fibre to yarn
c. weaving iii. angora goat
d. synthetic iv. removing fleece
e. scouring v. acrylic
f. spinning vi. changing yarn to fabric
g. mohair vii. raising silkworms
 

Answer:

Column I Column II
a. shearing iv. removing fleece
b. sericulture vii. raising silkworms
c. weaving vi. changing yarn to fabric
d. synthetic v. acrylic
e. scouring i. cleaning wool
f. spinning ii. changing fibre to yarn
g. mohair iii. angora goat

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Question 8:

List four types of natural fibres and their sources.

Answer:

Four types of natural fibres and their sources are as follows:

(a) Cotton is obtained from cotton plants.
(b) Jute is obtained from the stems of jute plants.
(c) Silk fibre is obtained from the cocoons of silkworms.
(d) Wool is obtained from the hair of goats, sheep, etc.

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Question 9:

Your mother goes to buy a woollen shawl from the market. The shopkeeper takes out a small strand of yarn from the shawl and burns it. It smells of burning plastic. Will it be a good decision to buy the shawl? Give reasons for your answer.

Answer:

The smell of burning wool is like that of burning hair. But, the small strand of yarn that the shopkeeper takes out from the shawl burns with a smell similar to that of burning plastic. This shows that the shawl is not pure woollen. Instead, it is made of some synthetic yarn. Thus, it will not be a good decision to buy that shawl.

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Question 10:

We wear clothes according to the weather. Explain this sentence with suitable examples.

Answer:

 We wear clothes according to the weather. Some examples that explain this are as follows:
(a) We usually wear clothes made of cotton fabrics during the hot days of the summer season. This is because cotton feels cool and it absorbs sweat easily.
(b)
Woollen clothes are worn in the cold days of the winter season. This is because wool is the warmest of all fibres.
(c) Clothes made of silk fabrics and synthetic fabrics are comfortable when the weather is neither very hot nor very cold.

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Question 11:

List the various stages in the life cycle of a silkworm. Can you name some other insect that have a similar life cycle?

Answer:

The various stages in the life cycle of a silkworm are as follows:

  1. Egg
  2. Larva
  3. Pupa
  4. Adult moth
Spiders have a similar life cycle.

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Question 12:

Write a short note on the health problems of a worker in the silk industry.

Answer:

Workers in the silk industry suffer from respiratory disorders. This is due to the inhalation of vapours from the boiling cocoons and the diesel used to run the machines. The loud and deafening music played at the workplace to block out the sounds of the machinery affects their hearing. The workers have to dip their hands into hot water to check whether the silk threads have loosened enough to be removed from the cocoons. This causes blisters and open wounds.

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Question 13:

Name some animals other than sheep that yield wool.      

Answer:

Some animals other than sheep that yield wool are as follows:
(a) Yak wool is common in Tibet and Ladakh.
(b)
Angora wool is obtained from angora goats that are found in hilly regions such as Jammu and Kashmir.
(c) The fur on the body of camels is also used as wool.
(d) Llama and alpaca found in South America also yield wool.

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Question 14:

Differentiate between the following:
(a) shearing and scouring
(b) cashmere and angora

Answer:

(a)

Shearing Scouring
The fleece along with a thin layer of skin is removed from the body of a sheep. This process is called shearing. The sheared skin along with the hair is thoroughly washed in tanks to remove dust, grease and dirt. This process is called scouring.


(b)
Cashmere Angora
Cashmere is a very expensive and fine fibre obtained from goats that grow fine fur-like hair on their bodies during the severe winter months. The fibres obtained from angora rabbits and angora goats are called angora.



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