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