NCERT PRACTICE 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:
Ans.- a) Wool is obtained from hairs of the sheep. b) White fleece of the lamb refers to the white color of the 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.
Ans.- (iii) both a and b
3. Which of the following does not yield wool?
(i) Yak (ii) Camel (iii) Goat (iv) Woolly dog
Ans.- (iv) Woolly dog
4.What is meant by the following terms? (i) Rearing (ii) Shearing (iii) Sericulture
Ans.- 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, __________, __________, _________.
Ans.- Scouring, picking of burrs, dying of fibers, 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.
Ans.-
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
Ans.- Sericulture and Moriculture
8. Match the words of Column I with those given in Column II:
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 fibers |
Junior Science Topic - Fiber To Fabric. Chapter notes, video lectures, power point presentation and NCERT exercise solution. (Class 7, CBSE syllabus, chapter 03)
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