RBSE Solutions for Class 7 Science Chapter 3 Fibre to Fabric

Rajasthan Board RBSE Solutions for Class 7 Science Chapter 3 Fibre to Fabric Textbook Exercise Questions and Answers.

RBSE Class 7 Science Solutions Chapter 3 Fibre to Fabric

RBSE Class 7 Science Fibre to Fabric InText Questions and Answers

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Question 1. 
Boojho is wondering why it hurts when someone pulls his hair but not when he goes for a haircut?
Answer:
Hair is made up of proteins which are dead cells. They are attached to the scalp with living cells from where they grow. So while getting a haircut, a person does not feel pain because dead cells are being cut, but when it is pulled from the scalp, the living cells are also being pulled along and it hurts.

Question 2. 
Boojho is wondering why a cotton garment cannot keep us warm in winter as a woolen sweater does? 
Answer:
Woolen sweater traps air in between whereas cotton allows the air to pass through it. Air being a bad conductor of heat does not let body heat to escape beyond the sweater. Therefore it is much warmer.

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Question 3. 
Paheli wants to know if the cotton thread and silk thread are spun and woven in the same manner.
Answer:
Yes, to some extent cotton threads and silk threads are spun and woven in the same manner.

RBSE Class 7 Science Fibre to Fabric Textbook Questions and Answers  

Question 1. 
You must be familiar with the following nursery rhymes:
(i) ‘Baa baa black sheep, have you any wool.’
(ii) ‘Mary had a little lamb, whose fleece was white as snow.’
Answer the following:
(a) Which parts of the black sheep have wool?
(b) What is meant by the white fleece of the lamb?
Answer:
(a) Wool from the black sheep is obtained from the:

• Coarse beard hair.
• Fine soft under hair close to the skin.

(b) White fleece of the lamb means white hair of the lamb.

Question 2. 
The silkworm is: 
(a) a caterpillar 
(b) a larva. 
Choose the correct option.
(i) (a), (ii) (b), (iii) both (a) and (b), (iv)neither (a) nor (b).
Answer:
(iii) Both (a) and (b).

Question 3. 
Which of the following does not yield wool?
(i) Yak
(ii) Camel 
(iii) Goat
(iv) Woolly dog 
Answer:
(iv) Woolly dog.

Question 4. 
What is meant by the following terms?
(i) Rearing (ii) Shearing (iii) Sericulture.
Answer:
(i) Rearing:
Rearing of animals means taking care of economically useful animals by managing their breeding, feeding, medical care etc. for obtaining one or more of their useful product for human being.

(ii) Shearing:
The process of removal of fur from the skin of the animal.

(iii) Sericulture:
The rearing of silkworms for obtaining silk.

Question 5. 
Given below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.
Shearing, ........................,  sorting, ........................, ........................, ........................
Answer:
scouring, cleaning of burrs, dyeing, rolling.

Question 6. 
Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.
Answer:
 

Question 7. 
Out of the following which are the two terms related to silk production? Sericulture, floriculture, moriculture, apiculture and silviculture.
Hints: 
(i) Silk production involves cultivation of mulberry leaves and rearing silkworms.
(ii) Scientific name of mulberry is Moms alba.
Answer:
(i) Sericulture 
(ii) Moriculture 

Question 8. 
Match the words of column I with those given in column II:

Answer:

Question 9. 
Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words:
Down (D)    
1. Thorough washing 
2. Animal fibre 
3. Long thread like 

Across (A)
1. Keeps warm
2. Its leaves are eaten by silk - worms
3. Hatches from structure egg of moth

Answer: