Weaving of silk cloth. Soln: The answer is (c) protein. Describe the life history of silk moth with the help of figures of various stages. Silk is an animal protein fibre produced by certain insects, like worms and spiders, to build their cocoons and webs.Ugly to some, these little silk worms are the very beginning of the incredible … Silkworms eat mulberry leaves, and are native to northern China.. Silk moth pupae are eaten in some cultures. 6.6 Silk fibre-reinforced composites. Mahatma Gandhi was critical of silk production based on the Ahimsa philosophy "not to hurt any living thing". Bombyx mori females are also one of the few organisms with homologous chromosomes held together only by the synaptonemal complex (and not crossovers) during meiosis. Fat. The most common variety of silk is – (a) Tussar silk (b) Kota silk (c) Mulberry silk (d) Mooga silk iv. Cellulose fibers (/ ˈ s ɛ lj ʊ l oʊ s,-l oʊ z /) are fibers made with ethers or esters of cellulose, which can be obtained from the bark, wood or leaves of plants, or from other plant-based material. Cotton fibre is the purest source of cellulose and the most significant natural fibre. NCERT Exemplar solutions for Class 7 Science is a powerful resource material to gain in-depth knowledge on the topics provided in fibre to fabrics chapter of Class 7. Protein. (a) Silkworms are caterpillars of the silk moth. Other Silkworm Moths. Answer (b) Question 9. Paheli went to the market to buy sarees for her mother. Diseases 7. Production of sarees. Sericulture, the practice of breeding silkworms for the production of raw silk, has been under way for at least 5,000 years in China,[1] whence it spread to India, Korea, Nepal, Japan, and the West. The final molt from larva to pupa takes place within the cocoon, which provides a vital layer of protection during the vulnerable, almost motionless pupal state. They are not monophagous, since they can eat other species of Morus, as well as some other Moraceae, mostly Osage orange. It is the closest relative of Bombyx mandarina, the wild silk moth. … 22. (a) Silk and Wool fibres are obtained from animals. The domesticated B. mori and the wild B. mandarina can still breed and sometimes produce hybrids. Reeling of silk is (a) a process of making silk reels. On the other hand, fabric is the accumulation of many fibre threads which are hard to break and needs an enormous amount of energy to break the fabric. Very Short ... Thread which burns with the smell of burning paper is of cotton because both paper and cotton are cellulose (c) weaving of silk cloth. It is one of the important animal fibres obtained from silkworm. For more information visit BYJU’S website or download BYJU’S learning App. Wool can be obtained from animals like sheep, goat, camel, yak, rabbit, etc. (d) The larvae/caterpillars or silkworms are kept in clean trays along with freshly chopped mulberry leaves. Reeling of silk is (a) a process of making silk reels. 14. (b) spinning of silk fibres. Write various steps for processing fibres into wool. [24] However, these worms, not being selectively bred as such, are possibly inferior in silk production and may exhibit other undesirable traits. Very Short Answer Type Questions. According to a Vietnamese folk tale, silkworms were originally a beautiful housemaid running away from her gruesome masters and living in the mountain, where she was protected by the mountain god. Yarns are then woven, knitted or bonded into fabric. In China, a legend indicates the discovery of the silkworm's silk was by an ancient empress named Leizu, the wife of the Yellow Emperor, also known as Xi Lingshi. The answer is (b) rearing of the silkworm. False- Yak hair is used to make woollen fabric. During these movement of head, the silkworm secrets fibre made of protein which hardens on exposure to air and becomes silk fibre (or silk thread). Silkworms secrete fibre made of GC Fibres Polymers Silkworms secrete fibre made of. Hence, based on making of fabric from fibre it is said that unity is strength. (d) selecting fine hair for good quality wool. Making silk fabric from silk yarn. Fill in the blanks in the following statements. Healthier larvae have greater pupation rates and cocoon weights. (c) making silk fabric from silk yarn. The fibres are scoured again and dried. The domestic silk moth was domesticated from the wild silk moth Bombyx mandarina, which has a range from northern India to northern China, Korea, Japan, and the far eastern regions of Russia. 4 Structure of fibres A fibre is defined as a unit of matter with a length at least 100 times its diameter, a structure of long chain (b) In India, camels and goats are generally reared for obtaining wool. Required fields are marked *, Frequently Asked Questions NCERT Exemplar for Class 7 Science Chapter 3 Fibre to fabric. The domestic silk moths cannot fly, so the males need human assistance in finding a mate, and it lacks fear of potential predators. Nylon is a synthetic fibre. It is easy to break a fibre thread as it is fragile and easy to break as well. Shearing does not hurt the sheep just as it does not hurt when you get a hair cut or your father shaves his beard. Bombyx mori, the domestic silk moth, is an insect from the moth family Bombycidae. 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