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