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 are very fine and lustrous, about 1 0 μ m (0. Why is silk obtained by mulberry silk moth most popular? 4.Question. 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. by the 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 … Question 19. 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. 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. Example: Nylon, Polyester and Acrylic. View Answer. While constructing its cocoon, the silkworm will twist in a figure-8 motion about 300,000 times and produce around 1 kilometer of filament. Plant fibres are obtained from fruits and stems. xi. Life cycle of the silk moth Inside the cocoon, the silkworm enters the second stage of its life (called the pupa) and then … Silk fiber is obtained from the cocoons of the silk moth. 1. Silk fibre obtained from Silk moth is a kind of of Insect secretion. The silkworm takes three to seven days to prepare the cocoon, formed by about 20-39 concentric layers of a single thread. From which parts of the cotton and jute are obtained? Silk fibres are drawn from the cocoon of the silkworm. True. Answer: Cotton is obtained from the fruits of the cotton plant, called cotton balls. 3.9). Female silk moth lay eggs. SOLUTION: (A) True (B) False : Spinning is the process of making yarn from fibres. (False) (g) Polyester is a natural fiber. Jute fibre is obtained from the stem of the jute plant. Silk fibres are then spun into silk threads, which are finally woven into silk cloth by weavers. Plant fibres: Fibres obtained from … Man-made or Synthetic Fibre The fibres which are prepared from chemical substances in factories are called synthetic fibres. Question: Write the maximum length of continuous silk thread that can be obtained from a cocoon. The silk fibre obtained from the cocoon of mulberry silk moth are soft and lustrous. Answer. ; 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. Question 1. Silkworms are fed on mulberry leaves. 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. | EduRev Class 7 Question is disucussed on EduRev Study Group by 112 Class 7 Students. Explanation:. plants and animals. But at times, the moth dissolves the silk to emerge out of the cocoon. Class 7. x. Yarn is made from fibre. Describe the process of obtaining silk fibres from the cocoon. Answers. There is a chain of method in manufacturing Silk from Cocoons. In which of the following process, threads are taken out from the cocoons? 13 min. 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. The fibres are of two types:1 Natural fibres 2 Synthetic fibres. Silk: Cocoon, Wool: ____ … Q3. Silk is natural, not a man-made polymer. Silk thread is obtained from (a) Cocoon (b) Caterpillar (c) Pupa (d) Adult moth (a) Cocoon. These machines unwind the fibers of silk or threads from the cocoon. Different types of silk, with different textures, are obtained from different varieties of silk moths. Fig. 3. Silk is a continuous filament within each cocoon, having a usable length of about 600 to 900 metres (2,000 to 3,000 feet). This covering is known as cocoon . What are synthetic fibres? xii. fill in the blanks: Answer. Silk is a natural fibre. Silk fibres are used for weaving silk cloth. 2. Silk. 4. Write a short note on silk. Study Materials ... What is the process of taking out silk threads from the cocoon known as? We get silk from silk worm. Free Question Bank for 7th Class Science Fibre to Fabric Fibre to Fabric NCERT Solution for Class 6 Science. A Moth that Gives Cloth. Synthetic fibres are man-made fibres and are not obtained from any plant and animal sources. Solution: (c) The breeding and management of silkworms for the production of silk is known as sericulture. Can you imagine that the soft silk yarn is as strong as a comparable thread of steel! ix. 1. The fibres obtained from plants and animals are called natural fibres. Q7: Name two items that are made from Jute fibre. MCQ Questions for Class 7 Science with Answers are.