{"id":24251,"date":"2021-06-11T18:15:55","date_gmt":"2021-06-11T12:45:55","guid":{"rendered":"https:\/\/mcq-questions.com\/?p=24251"},"modified":"2022-03-02T10:38:22","modified_gmt":"2022-03-02T05:08:22","slug":"ncert-solutions-for-class-7-science-chapter-3","status":"publish","type":"post","link":"https:\/\/mcq-questions.com\/ncert-solutions-for-class-7-science-chapter-3\/","title":{"rendered":"NCERT Solutions for Class 7 Science Chapter 3 Fibre to Fabric"},"content":{"rendered":"

These NCERT Solutions for Class 7 Science<\/a> Chapter 3 Fibre to Fabric Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.<\/p>\n

Fibre to Fabric NCERT Solutions for Class 7 Science Chapter 3<\/h2>\n

Class 7 Science Chapter 3 Fibre to Fabric Textbook Exercise Questions and Answers<\/h3>\n

Question 1.
\nYou must be familiar with the following nursery rhymes:
\ni. \u2018Baa baa black sheep, have you any wool.\u2019
\nii. \u2018Marry had a little lamb, whose fleece was white as snow\u2019.
\nAnswer the following:
\na. Which parts of the black sheep have wool?
\nb. What is meant by the white fleece of the lamb?
\nAnswer:
\na. The fleece (hair) of the black sheep has wool.
\nb. White fleece of the lamb means the white coloured hair on the skin of the sheep.<\/p>\n

Question 2.
\nThe silkworm is: (i) a caterpillar, (ii) a larva.
\nChoose the correct option:
\na. (i)
\nb. (ii)
\nc. Both (i) and (ii)
\nd. Neither (i) nor (ii)
\nAnswer:
\nc. Both (i) and (ii)<\/p>\n

Question 3.
\nWhich of the following does not yield wool?
\na. Yak
\nb. Camel
\nc. Goat
\nd. Woolly dog
\nAnswer:
\nd. Woolly dog<\/p>\n

Question 4.
\nWhat is meant by the following terms?
\na. Rearing
\nb. Shearing
\nc. Sericulture
\nAnswer:
\na. Rearing: The process of keeping, feeding, breeding and taking medical care of useful animals is called rearing of animals. These animals produce one or more useful products for human use.<\/p>\n

b. Shearing: The fleece (hair) of sheep is shaved off along with the thin layer of skin. This is similar to shaving beards or hair and this process is called shearing.<\/p>\n

c. Sericulture: The rearing of silkworms for obtaining silk is called sericulture.<\/p>\n

\"NCERT<\/p>\n

Question 5.
\nGiven below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.
\nShearing, …………., sorting, …………., …………., ………….
\nAnswer:
\nShearing, Scouring, sorting, removing burrs, dying and rolling into yarns.<\/p>\n

Question 6.
\nMake sketches of the stages in the life history of the silk moth which are directly related to the production of silk.
\nAnswer:
\n\"NCERT<\/p>\n

Question 7.
\nOut of the following, which are the two terms related to silk production? Sericulture, Floriculture, Moriculture, Apiculture and Silviculture.
\nHints:
\na. Silk production involves cultivation of mulberry leaves and rearing silkworms.
\nb. Scientific name of mulberry is Morus alba.
\nAnswer:
\na. Sericulture
\nb. Moriculture.<\/p>\n

Question 8.
\nMatch the words of column I with those given in column II.<\/p>\n\n\n\n\n\n\n\n\n
Column I<\/td>\nColumn II<\/td>\n<\/tr>\n
1. Scouring<\/td>\n(a) Yields silk fibres<\/td>\n<\/tr>\n
2. Mulberry leaves<\/td>\n(b) Wool yielding animal<\/td>\n<\/tr>\n
3. Yak<\/td>\n(c) Food of silkworm<\/td>\n<\/tr>\n
4. Cocoon<\/td>\n(d) Reeling<\/td>\n<\/tr>\n
(e) Cleaning sheared skin<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Answer:
\n1. (e)
\n2. (c)
\n3. (b)
\n4. (a)<\/p>\n

Question 9.
\nGiven below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
\n\"NCERT
\nAnswer:
\n1D. Scour 1A. Wool
\n2D. Silk 2A. Mulberry
\n3D. Fibre 3A. Caterpillar<\/p>\n

\"NCERT<\/p>\n

NCERT Extended Learning Activities and Projects<\/span><\/p>\n

Question 1.
\nPaheli wants to know the maximum length of continuous silk thread that can be obtained from a cocoon. Find out for her.
\nHint:
\nThe maximum length of continuous silk that can be obtained from a cocoon is approximately 900 metres.<\/p>\n

Question 2.
\nBoojho wants to know why caterpillars need to shed their skin when they grow bigger but we humans do not. Do you have any idea?
\nHint:
\nThe skin of caterpillars does not grow. As their body grows, they have to move out of their skin because it becomes too tight for them. However, humans\u2019 skin also grows with their body and hence is not required to shed.<\/p>\n

Question 3.
\nBoojho wants to know why caterpillars should not be collected with bare hands. Can you help him?
\nHint:
\nCaterpillars are toxic and can cause allergy when touched with bare hands.<\/p>\n

Question 4.
\nPaheli wanted to buy a silk frock and went to the market with her mother. There they found that the artificial (synthetic) silk was much cheaper and wanted to know why. Do you know why? Find out.
\nHint:
\nArtificial silk or rayon is produced in mills in bulk at one time and requires less labour and skill whereas original silk is produced by the silkworms and it requires a lot of skill, labour and time to treat the worms and extract silk from them. Hence artificial silk is cheaper than natural silk.<\/p>\n

\"NCERT<\/p>\n

Question 5.
\nSomeone told Paheli that an animal called \u2018Vicuna\u2019 also gives wool. Can you tell her where this animal is found? Look for this in a dictionary or an encyclopaedia.
\nHint:
\nVicuna are native to the central Andes in South America. They are found in Peru, north-western Argentina, Bolivia, and northern Chile.<\/p>\n

Question 6.
\nWhen handloom and textile exhibitions are held, certain stalls display real moths of various varieties of silk and their life histories. Try and visit these stalls with elders or teachers and see these moths and stages of their life history.
\nHint:
\nDo yourself.<\/p>\n

Question 7.
\nLook for eggs of any moth or butterfly in your garden or park or any other place full of plants. They look like tiny specks (dots) laid in a cluster on the leaves. Pull out the leaves containing eggs and place them in a cardboard box. Take some leaves of the same plant or another plant of the same variety, chop them and put them in the box. Eggs will hatch into caterpillars, which are busy eating day and night. Add leaves every day for them to feed upon. Sometimes you may be able to collect the caterpillars. But be careful. Use a paper napkin or a paper to hold a caterpillar. Observe everyday. Note the.
\na. number of days taken for eggs to hatch,
\nb. number of days taken to reach the cocoon stage,
\nc. number of days to complete life cycle.
\nHint:
\na. The hatching period varies from insect to insect. For example: in houseflies, the eggs hatch out within 10 to 15 hours of copulation.
\nEggs of the moth or caterpillars hatch in 2-3 weeks.
\nb. In common mulberry silk moth, the caterpillar completely transforms into pupa within 12 to 15 days.
\nc. It depends upon the insect moth or<\/p>\n

\"NCERT<\/p>\n

Activity 1<\/span><\/p>\n

Objective: To study the burning of different fibres used for making cloth.
\nMaterials Required: One fibre each of wool, silk, rayon and nylon, forceps, candle and a
\nmatchbox.
\nProcedure:<\/p>\n