SCERT 7th Science 3 ls all question answers
Answers
Answer:
Explanation:
Access Answers of NCERT Solutions for Class 7 Science Chapter 3 – Fibre to Fabric
Exercise Questions
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?
Solution:
a) Wool is obtained from hairy fibres of the sheep.
b) White fleece of the lamb refers to the white colour of their fur.
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.
Solution:
(iii) both a and b
3. Which of the following does not yield wool?
(i) Yak (ii) Camel (iii) Goat (iv) Woolly dog
Solution:
The answer is (iv) Woolly dog
4.What is meant by the following terms? (i) Rearing (ii) Shearing (iii) Sericulture
Solution:
i) Raising of domestic animals like sheep, goat, yak, cow and buffaloes for commercial purposes such as for milk and fur is known as rearing.
ii) Shearing is a process of removal of animal hair by using machines similar to those used by barbers.
ii) Rearing of silkworms to get silk is known as Sericulture.
5. Given below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.
Shearing, __________, sorting, __________, __________, _________.
Solution:
Shearing, Scouring, sorting, picking of burrs, dying of fibres, making of yarn.
6. Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.
Solution:
Life history of silk moth
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 Morus alba
Solution:
Sericulture and moriculture
8. Match the words of Column I with those given in Column II:
Column-I
Column-I
1. Scouring
(a) Yields silk fibres
2. Mulberry leaves
(b) Wool yielding animal
3. Yak
(c) Food of silkworm
4. Cocoon
(d) Reeling
(e) Cleaning sheared skin
Solution:
Column-I
Column-I
1. Scouring
(e) Cleaning sheared skin
2. Mulberry leaves
(c) Food of silkworm
3. Yak
(b) Wool yielding animal
4. Cocoon
(a) Yields silk fibres
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 : Animal fibre
Across
(A) 1 : Keeps warm
2 : Its leaves are eaten by silkworms
3: Hatches from egg of moth
Puzzles of fibres and fabric
Solution:
Down:
1D. Scour
2D. Silk
3D. Fibre
Across
1A. Wool
2A. Mulberry
3A. Caterpillar
Importance topics covered in Class 7 Science NCERT Chapter 3 Solutions – Fiber to Fabric
Fibres
Types of fibres
Silk
Wool
Sources of wool
How to process wool fibre?
Fibres – Fine, long, filaments or continuous threads are acquired for the animals and plants. There are 2 types of fibre. They are – Plant fibre and Animal fibre.
Silk – Silk and woollen are the usual fibres obtained from animals. Silk is obtained from the silkworms whilst, wool is obtained from the goat, sheep and yak. Therefore, wool and silk are animal fibres.
Animal fibre – Hair of alpaca, llama and camel are handled and processed to produce the wool. Generally, in India, sheep are nurtured and reared for getting the wool. The hair of the sheep is shaved off from the body, cleansed, dried, sorted, coloured, gyrated and woven to get the wool.
Sources of wool – Wool is acquired from yak (Ladakh and Tibet), Angora goat, sheep, goat, camel, Alpaca etc.,
Hence, this is a small introduction of the NCERT Solutions for Class 7 Science chapter 3. We at BYJU’S provide solutions for all the classes in a simple and an easier way. BYJU’S provides solutions for all the classes and chapters, in brief, you can refer class 7 science other chapters here. For more NCERT solutions, study materials of all the subjects and all the classes visit BYJU’S or download the app for more information and learning experience.
Frequently Asked Questions on Fibre to Fabric
Which parts of the black sheep have wool?
Wool is obtained from hairy fibres of the sheep.
What is meant by the white fleece of the lamb?
White fleece of the lamb refers to the white colour of their fur.
What is meant by Rearing?
Raising of domestic animals like sheep, goat, yak, cow and buffaloes for commercial purposes such as for milk and fur is known as rearing.
What is meant by Shearing?
Shearing is a process of removal of animal hair by using machines similar to those used by barbers.
Define Sericulture?
Rearing of silkworms to get silk is known as Sericulture.
Which term is used for silk production?
Sericulture and moriculture