The process of taking out threads from the cocoon for use as silk is called: (a . This covering is known as cocoon. The rearing of silkworms for obtaining silk is called (a) cocoon (b) silk (c) sericulture (d) silviculture 2. The moth continues to develop within the cocoon. The silk thread (yarn) is obtained from the silk moth's cocoon. The pile of cocoons is used for obtaining silk fibres. ; These silkworms feed on the mulberry leaves giving rise to pupa. There is a variety of silk moths which look very different from one another and the silk yarn they yield is different in textures (coarse, smooth, shiny, etc.) Then, the chapter moves on to explain a very useful fibre - wool. Silk is a luxurious fabric spun from the cocoons of a moth, Bombyx mori. Wool is obtained from the fleece (hair) of fleece sheep or yak. Processing Cocoon-Obtained Silk. (a) culture of bacteria. Fibre to Fabric Class 7 Extra . This can avoid the mixing of silk. The most common silk moth is the mulberry silk moth. Very Short Type Questions Solution: (1) Ans:- Two fibres obtained from animals are wool and silk. The general process that takes place at a sheep shearing shed is. Reeling of silk is. Silkworms secrete fibre made of (a) fat (b) cellulose (c) protein (d) nylon; Very Short Answer Type Questions. This Fiber is nep free. How is silk processed? Ans. A large number of these cocoons are unwound carefully to make long threads. Question 1. The silk fibres are separate out. Q 11 - Fibre is obtained from (a) animals Silk is obtained from (b) plants (c) both(a) and (b) (d . 3. Now the wool is ready to be drawn into fibres. ________ is the removal of the fleece of the sheep along with a thin layer of the skin. Then, the spinning of silk fibres into threads is done. The term sericulture is used for. Correct option is C) Cocoon is a protective case of silk or similar fibrous material spun by the larvae of moths and certain other insects as a cover for the pupa. It is ve.. Silk fibres obtained from cocoons are spun (twisted) to form silk threads called silk yarn. Silk fibre is obtained from A. fleece of sheep B. cotton ball C. cocoon D. shiny jute stalk. 5. In order to obtain silk, mulberry trees are cultivated, silkworms are reared and their cocoons are collected to get silk fibres. Cocoons are collected and kept under the sun, or boiled, or exposed to steam. (b) Fibres are taken out from the cocoon. Class 7 Chemistry Fibre to Fabric Silk Silk Silk fibre is obtained from the cocoon of the silk moth. Class 7 Science Fibre To Fabric Extra Questions Question 15. . The yarn made from A is used for knitting seaters whereas the made from B is used for weaving saris. - the answers to answers-in.com (a) Goat (b) Llama (c) Alpaca (d) Moth Soln: Answer is (d) Moth Explanation: (c) weaving of silk cloth. Paheli wanted to buy a gift made of animal fibre obtained without killing the . The wool yielding animals bear a thick coat of hair on their body. Step 5. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. Silk moth lays eggs, and then eggs hatch into larva, or caterpillar C the silkworm. The cocoon is made of a thread of raw silk from 300 to about 900m(1,000to3,000ft) long. The cocoons are kept under the sun or boiled or exposed to steam. It is ready to spin and ready to make handspun yarn. (a) a process of making silk reels. The fibres that constitute these fabrics can always be sourced from natural origins. Silkworms are raised throughout this procedure at the proper temperature and humidity to extract silk threads from cocoons. Fur and leather are animal products which are obtained from the skin of animals by killing them. Cocoons are collected and kept under the sun, or boiled, or exposed to steam. Question: Define Shearing and Scouring. These MCQ Questions on Fibre to Fabric Class 7 with answers pave for a quick revision of the Chapter thereby helping you to enhance subject knowledge. 8.) Silk fibres come from cocoons of the silk moth. To extract the silk fibres, cocoons are gathered, left outside in the sun, or cooked. (ii) Processing of cocoons to obtain silk fibres: The pile of cocoons is placed in hot water. Silk is great for summer clothing because of its absorbent nature and how it wicks moisture and it is also a staple for winter wear since it has low conductive properties. (d) the process of taking silk threads from cocoon. Silk fibre is obtained from (a) fleece of sheep (b) cotton ball (c) cocoon (d) shiny jute stalk Soln: Answer is (c) cocoon Explanation: Silk is a fibre obtained from the cocoons of silkworms. The wool-yielding animals bear a thick coat of hair on their body. (b) separating hair of different textures. Silk is primarily used in garments and household items but it is also employed in unexpected ways such as in bicycle tires and in medicine. The process by which silk thread is separated from the cocoon is called reeling the silk. The process of taking out threads from the cocoon for use as silk is called reeling the silk. These MCQ Questions on Fibre to Fabric Class 7 with answers pave for a quick revision of the Chapter thereby helping you to enhance subject knowledge. Answer: Shearing: The process of removal of the woolen coat or fleece from an animal is called shearing. Once the cocoon is formed it dissolved in boiling water to extract the individual long fibre from it. The silk yarn is obtained from the cocoon. The caterpillar soon covers itself with silk fibres and becomes a pupa. (c) making silk fabric from silk yarn. Question 4. Silk is obtained from the cocoons of silkworms. Hair keeps these animals warm because hair trap air which does not let the heat release from their body due to its . To obtain silk fibre the pile of cocoons are kept under the sun or boiled or else exposed to steam to separate the silk fibres. The silk fibres are thus separated out. Clothes are manufactured from fabrics or clothing material which are woven from fibres. 9. An adult silkworm has a wingspan of 40 to 50 mm (about 2 inches) and has a thick bristly body (the adult female is larger than the adult male). Answer: Cocoons of silk moth are used to obtain the silk fibres. The term sericulture is used for. If cocoons are not boiled then the fine thread of silk will not be obtained and also the cocoons will be brittle in . (a) Mulberry silk (b) Tassar silk (c) Mooga silk (d) Moth silk 3. Q.2. Answer:- a) Removal of fleece. The larva of silk worm is called3. This helps in separating out the silk fibres. (d) Moth. These threads are spun together to make them thicker and then woven to make silk. Silk fibers are produced on demand from special silk glands of several groups of invertebrate animals such as silk moths. A) Culture of bacteria. Do you know which part of the sheep's body yields fibres? Both cocoons and silk were obtained from local sites of sericulture in each sampling location. Wool is obtained from the fleece (hair) of sheep or yak. Stage 1: Egg An egg is the first stage of the life cycle of the silkworm. CBSE Class 7 Science Chapter 3 Notes Fibre to Fabric Fibre to Fabric Class 7 Notes Understanding the Lesson. In fact, the best-known silk fibers are obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity. Reeling is done in special machines, which unwind the threads or fibres of silk from the cocoon. In Class VI you have learnt about some fibres obtained from plants. Different Varieties of Silk The silk produced by the silkworms of different varieties of silk moths is different in texture (coarse, smooth, shiny, etc. ; During this stage, a weave is netted around by the silkworm to hold itself. This fibre is made of a protein and becomes the silk fibre. There are 2 types of sheep fibres. The life cycle of the silkworm is explained below in detail. The silk fibres separate. Silk fibers are made from a protein produced by the silkworm, Bombyx Mori. 2. Answer. 2. The process by which silk thread is separated from the cocoon is called reeling the silk. You also learnt that wool and silk fibres are obtained from animals. (d) rolling of sheep fibre into yarn. Answer: the process of rearing of silkworms for obtaining silk. Silk and wool fibres are obtained from animals. The Class 7 Science, Chapter 3 - Fibre to Fabric helps us understand how the fabric that we use in our day-to-day lives is produced from the fibre. In this chapter, we study the concepts of natural and man-made fibres. The silk yarn is obtained from the cocoon of the silk moth. The silk fibres so obtained are weaved to make silk cloth. Question 4. This is the silk fibre. Answer: A pile of cocoons is used for obtaining silk fibres. The general process that takes place at a sheep shearing shed is. Wool is obtained from the fleece (hair) of sheep or yak and silk fibres come from cocoons of the silk moth. Ans. The fibres are dyed in various colours because the natural fleece of sheep and goats is black, brown or white. Question: Explain the process to obtain silk thread from cocoon. Study Material and Notes of Ch 3 Fibre to Fabric Class 7th Science. (c) After 25 to 30 days, the caterpillars stop eating and start spinning cocoons. The silk fibres are separate out. 3. (4) Ans:- Kashmiri goa t. (5) Ans:- Llama and Alpaca are found at South America. Hot water makes the silk fibres of cocoons to separate out. Weavers weave silk threads into silk cloth. Silkworms are larvae of silk moth. Explain the process to obtain silk thread from cocoon. C) Making silk fabric frim silk yarn. The quality of silk production can be improved by separately reeling silk fibers of male and female cocoons. Thereafter, these are spun into silk threads and are woven into silk cloth by weavers. The small fluffy fibres called burrs, are picked out from the hair. Question 1. How is silk fibre obtained from cocoon? The silkworms enclose themselves completely inside the silken cocoons in two or three days. Arrange them in their proper sequence. True. The silk thread or yarn is obtained from the silk moth's cocoon. Ans: - Cocoons are boiling to get silk fibre from it. 3.The silk threads obtained are woven into the desired clothes. Wool is obtained from the hair of sheep, camel, vicuna, llama, alpaca, goat, and even rabbits. Have a glance at the MCQ of Chapter 3 Science Class 7 and cross-check your answers during preparation. Silk is one of the earliest animal fibers utilized by humans, and SFFs exposed many biological micromolecules on the surface.

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how are silk fibres obtained from cocoons class 7

how are silk fibres obtained from cocoons class 7