Silk worms are cultivated by farmers in rural areas by feeding mulberry leaves to the worms 2. Natural fibres are obtained from natural sources, i.e. Can you imagine that the soft silk yarn is as strong as a comparable thread of steel! Silk fibre is obtained from the cocoon of the silk moth. 0 0 0 4 i … The cocoon is made of a thread of raw silk from 3 0 0 to about 9 0 0 m (1, 0 0 0 t o 3, 0 0 0 f t) long. For obtaining good quality silk filaments, the cocoons are boiled before the moth can emerge from them. Silk is a natural fibre. Fibre to Fabric Class 7 Extra Questions HOTS. Write a short note on silk. Legend has it that a Chinese princess was sipping tea in her garden when a cocoon fell into her cup, and the hot tea loosened the long strand of silk. Silk fibers are then converted into silk threads to make different kinds of silk fabrics like silk sarees, etc. 4. NCERT Solution for Class 6 Science. (f) False, as silk fibre is obtained from the cocoon … (e) True, as the process of arranging two sets of yarns together to make a piece of fabric is called weaving. MCQ Questions for Class 7 Science: Ch 3 Fibre to Fabric. Silk is a continuous filament within each cocoon, having a usable length of about 600 to 900 metres (2,000 to 3,000 feet). • Eggs are warmed to a suitable temperature for the larvae to hatch from the eggs. The fibres obtained from plants and animals are called natural fibres. Overview. This was just a brief layout about the sericulture. Different types of silk, with different textures, are obtained from different varieties of silk moths. Silk is a natural protein fiber, some forms of which can be woven into textiles.The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. 1. Silk fibre obtained from Silk moth is a kind of of Insect secretion. Cocoon: This is the pupa stage where the silkworm completes the formation of cocoon in a week under ideal conditions. Silk is obtained from. The fibres are of two types:1 Natural fibres 2 Synthetic fibres. Chapter 3 - Fibre to Fabric. Types of Fibres, Fibre to Fabric, Class 6. 2. We have Provided Fibre to Fabric Class 7 Science MCQs Questions with Answers to help students understand the concept very well. While constructing its cocoon, the silkworm will twist in a figure-8 motion about 300,000 times and produce around 1 kilometer of filament. These machines unwind the fibers of silk or threads from the cocoon. Silk thread is obtained from (a) Cocoon (b) Caterpillar (c) Pupa (d) Adult moth (a) Cocoon. The rearing of silkworms for obtaining silk is called (a) cocoon (b) silk (c) sericulture (d) silviculture. | EduRev Class 7 Question is disucussed on EduRev Study Group by 115 Class 7 Students. In which of the following process, threads are taken out from the cocoons? Study Materials ... What is the process of taking out silk threads from the cocoon known as? fill in the blanks: Answer. Man-made or Synthetic Fibre The fibres which are prepared from chemical substances in factories are called synthetic fibres. Free Question Bank for 7th Class Science Fibre to Fabric Fibre to Fabric 1. MCQ Questions for Class 7 Science with Answers are. The silk is mainly obtained from the cocoons of the Mulberry Silkworm (Bombyx mori). 1. 3. Classify the following fibres as natural or synthetic: nylon, wool, cotton, silk, polyester, jute. Silk is natural, not a man-made polymer. (False) (g) Polyester is a natural fiber. The rearing of silkworms to obtain silk is termed as sericulture. Cocoons are Placed in boiling water to get smooth & continious thread from it. Silk fiber is obtained from the cocoons of the silk moth. Q3. Fig. Silk moth: The pupa inside the cocoon develops into a silk moth and the life cycle of the silkworm is completed. Silk fibres are then spun into silk threads, which are finally woven into silk cloth by weavers. The fibres which are obtained from natural sources like plants and animals are called natural fibres.The fibres which are prepared from chemical substances in … The silk moth lives on the leaves of mulberry plants. Question 1. Cotton fibres Wool fibres Silkworm 2. (D) True (E) True (F) False : Silk fibre is obtained from silkworm (animal). (g) Polyester is a natural fibre. Check the below NCERT MCQ Questions for Class 7 Science Chapter 3 Fibre to Fabric with Answers Pdf free download. We get silk from silk worm. Learn Videos. (a) Plant fibers are obtained from cotton and jute. There are four stages in the life cycle of silk moth: eggs, larva, pupa and adult. Silk: Cocoon, Wool: ____ … Can you explain this answer? (1) Cotton: From fruit of the cotton plant. What are synthetic fibres? 6. Example: Nylon, Polyester and Acrylic. (F) Silk fibre is obtained from the stem of a plant. (b) Animals fibers are silk and wool. 3.9). It is also obtained from the hair of rabbits, yaks and camels. Question: Write the maximum length of continuous silk thread that can be obtained from a cocoon. Spinning is the twisting together of drawn out strands of fibers to form yarn. Question 19. Since filaments from a single cocoon are thin, five to ten cocoons are reeled simultaneously to obtain a single, strong and continuous silk thread. (C) False : Jute is obtained from jute plant (Corchorus). View Answer. The larva of the silk moth is called caterpillar. A silk saree. Silk is an expensive fabric. • The larvae are kept in clean trays along with freshly chopped mulberry leaves. Sep 28,2020 - What is the maximum length of the silk obtained from cocoon Related: Very Short Question Answers - Fibre to Fabric? Plant fibres are obtained from fruits and stems. silk fibres and turns into pupa. There is a chain of method in manufacturing Silk from Cocoons. Plant fibres: Fibres obtained from … Silk. plants and animals. Class 7 Chemistry Fibre to Fabric: Silk: Silk . 4.Question. (False) 3.Question. MCQ Questions for Class 7 Science with Answers were prepared based on the latest exam pattern. SOLUTION: (A) True (B) False : Spinning is the process of making yarn from fibres. View Answer. Jute fibre is obtained from the stem of the jute plant. The origins of silk date back to Ancient China. | EduRev Class 7 Question is disucussed on EduRev Study Group by 112 Class 7 Students. 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. (d) True, the process in which fibres are separated from the seeds of cotton by combing, is called ginning of cotton. Silk fibres are drawn from the cocoon of the silkworm. Explanation:. ; The silkworm secrete a certain type of fibre which is used for making silk ; Silworm secretions are very fine as it consists of traces of Keratin and other proteinaceous substances. It is freed by softening the binding sericin and then locating the filament end and unwinding, or reeling, the filaments from several cocoons at the same time, sometimes with a slight twist, forming a single strand. Silk is warm to wear during winters and cool in summer. Solution: (c) The breeding and management of silkworms for the production of silk is known as sericulture. The silk fibres so obtained are weaved to make silk cloth. Answer. Class 7. From which parts of the cotton and jute are obtained? The silkworm takes three to seven days to prepare the cocoon, formed by about 20-39 concentric layers of a single thread. - Silk thread is a protein fiber while cotton and jute yarn is cellulose. Answer. These fibres are not obtained from plant or animal sources. The scientific name of the Silk moth is Bombyx Mori. Ans. Silkworms are fed on mulberry leaves. Since hatching from the cocoon destroys the thread, to harvest the silk, the cocoon is placed in either boiling water, or blasted with steam or hot air, all processes that kill the pupae. Describe the process of obtaining silk fibres from the cocoon. Answer. The fibres are very fine and lustrous, about 1 0 μ m (0. Answers. MCQ Questions for Class 7 Science: Ch 3 Fibre to Fabric. Synthetic fibres are man-made fibres and are not obtained from any plant and animal sources. Q.4. 2. Example: Cotton, jute, silk, wool, etc. Students are advised to practice the NCERT MCQ Questions for Class 7 Science Chapter 3 Fibre to Fabric with Answers Pdf free download is available here. Fig. by the weavers. A Moth that Gives Cloth. Question 2. But at times, the moth dissolves the silk to emerge out of the cocoon. Female silk moth lay eggs. x. Yarn is made from fibre. Silk fibres are used for weaving silk cloth. The fibres obtained from plants and animals are called natural fibres. ix. For example, cotton from cotton bolls, jute from jute plant, silk from cocoon of silkworm and wool from hair of animals like sheep or goat. Silk has set the standard in luxury fabrics for several millennia. Reeling of the silk is carried out by special machines. This covering is known as cocoon . (f) Silk fiber is obtained from the stem of a plant. xii. Fibre to Fabric NCERT – Question: Define the term ‘selective breeding’. Answer: Cotton is obtained from the fruits of the cotton plant, called cotton balls. Q7: Name two items that are made from Jute fibre. Life cycle of the silk moth Inside the cocoon, the silkworm enters the second stage of its life (called the pupa) and then … True. Answer: The maximum length of continuous silk thread that can be obtained from a cocoon is more than that of 1000 feet (1000 to 1500 feet) continuous in length. Answer To obtain silk fibre from cocoon we have to place the piles of cocoons under the sunlight or in hot water and then with the help of the reeling process, silk fibres are separated out from the cocoons. • After 25 to 30 days the caterpillar stops eating and start spinning cocoon. viii. Answer: (i) Jute Sack bags (ii) Ropes Q8: Name two items that are made from coconut fibre. The silk fibre obtained from the cocoon of mulberry silk moth are soft and lustrous. This cocoon is sent for processing to produce a silk cloth. For example, cotton from cotton bolls, jute from jute plant, silk from cocoon of silkworm and wool from hair of animals like sheep or goat. How the silk fibres are obtained from cocoon? The further development of the pupa into moth continues inside the cocoon (Fig. 13 min. Nov 20,2020 - Silk thread is obtained froma)Cocoonb)Caterpillarc)Pupad)Adult mothCorrect answer is option 'A'. Why is silk obtained by mulberry silk moth most popular? xi.