Answer: D. Question 10: Silkworms secrete fibre made of. Bacteria based fabric 1. Fibre made from spider silk 7. Hair are of bad conductors of heat, hence they will not allow the escape of heat from the body, which ensures their bodies stay warm. Fill in the blanks in the following statements. Cotton fibre is the purest source of cellulose and the most significant natural fibre. viscose) and the synthetic fibres are made of mineral oil (e.g. (a) Eggs are warmed to a suitable temperature for the larvae to hatch from eggs. She was drinking tea under a tree when a silk cocoon fell into her tea. [citation needed]. Silkworms have been used in antibiotics discovery, as they have several advantageous traits compared to other invertebrate models. (c) The rearing of silkworms for obtaining silk is called silviculture. 10. K. Murugesh Babu, in Silk (Second Edition), 2019. The best-known silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity (sericulture).The … History of Mulberry Silkworm: Bombyx mori is popularly called the Chinese silkworm or Mulberry silkworm … [27] Major questions, however, remain unanswered, according to Jun Wang, co-author of a related study published in 2008,[28] who stated: "Whether this event was in a single location or in a short period of time in several locations cannot be deciphered from the data",[29] and research also has yet to identify the area in China where domestication arose. Often, the silkworm itself is eaten. A process of making silk reels. With the blessing of Guanyin, the girl was able to safely swallow that net into her stomach. 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 15. The moth – the adult phase of the lifecycle – is not capable of functional flight, in contrast to the wild B. mandarina and other Bombyx species, whose males fly to meet females and for evasion from predators. Fat and cellulose are not present in silk. A wholesale woollen fibre dealer gets the woollen fibre of different textures sorted for various purposes. The general process that takes place at a sheep shearing shed is. Very Short Answer Questions. The Chinese guarded their knowledge of silk, but, according to one story, a Chinese princess given in marriage to a Khotan prince brought to the oasis the secret of silk manufacture, "hiding silkworms in her hair as part of her dowry", probably in the first half of the first century AD. They grow in size and when the caterpillar is ready to enter the next stage of its life history called f) pupa, it first weaves a covering to hold itself, which is known as g) cocoon. Silk yarn is easily available as a waste product from textile processing, making silk fibre … When the color of their heads turns darker, it indicates they are about to molt. The domestic silk moth derives from Chinese rather than Japanese or Korean stock. 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. It is second only to maize in exploiting the principles of heterosis and crossbreeding. Give a reason for your answer. Fill in the blanks in the following statements. The girl died in her sleep, and as she wished to continue to help other people, her soul turned into silkworms. This enables sheep to survive without their protective coat of hair. has used research from the Universities of Wyoming and Notre Dame in a collaborative effort to create a silkworm that is genetically altered to produce spider silk. Fill in the blanks in the following statements. The longer fibres are made into wool for sweaters and the shorter fibres are spun and woven into woollen cloth. Usually, hair is removed during the hot weather. We provide NCERT Solutions, NCERT Exemplars, NCERT Textbooks, previous years question papers for all the subjects and classes. Mulberry silk, Tasar Silk and Mooga silk are the varieties of silk produced by different silkworms whereas Moth silk is not a variety of silk. A moth is a type of insect. The practice of raising silk moths by children as pets has, in non-silk farming South Africa, led to the development of extremely hardy landraces of silk moths, because they are invariably subjected to hardships not encountered by commercially farmed members of the species. Match the items of Column I with the items given in Column II. ADVERTISEMENTS: In this article we will discuss about Mulberry Silkworm:- 1. These enzymes are destructive to the silk and can cause the silk fibers to break down from over a mile in length to segments of random length, which seriously reduces the value of the silk threads, but not silk cocoons used as "stuffing" available in China and elsewhere for doonas, jackets, etc. made of cellulose (e.g. (a) Silkworms are caterpillars of the silk moth. 17. Reeling of silk is (a) a process of making silk reels. (c) weaving of silk cloth. Eggs take about 14 days to hatch into larvae, which eat continuously. [21][22] Since then, the silk production capacity of the species has increased nearly tenfold. As the process of harvesting the silk from the cocoon kills the larva, sericulture has been criticized by animal welfare and rights activists. Wool can be obtained from animals like sheep, goat, camel, yak, rabbit, etc. Health is dependent on factors such as better pupation rate, fewer dead larvae in the mountage,[23] shorter larval duration (this lessens the chance of infection) and bluish-tinged fifth-instar larvae (which are healthier than the reddish-brown ones). 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 … The domestic species, compared to the wild species, has increased cocoon size, body size, growth rate, and efficiency of its digestion. Breeding and management of silkworms for obtaining silk are called sericulture. They are implanted during reconstructive surgery to support or restructure damaged ligaments, tendons, and other tissue. The polyvoltine type of mulberry silkworm can only be found in the tropics. (c) washing of sheep fibre to remove grease. Many other Lepidoptera produce cocoons, but only a few—the Bombycidae, in particular the genus Bombyx, and the Saturniidae, in particular the genus Antheraea—have been exploited for fabric production. Using this knowledge they built a silk pavilion with 6,500 silkworms over a number of days. (d) the process of taking silk threads from cocoon. Life Cycle 5. Match the items in Column I with the woollen fibre in Column II. It has gained tolerance to human presence and handling, and also to living in crowded conditions. (b) spinning of silk fibres. Domestic silk moths are closely dependent on humans for reproduction, as a result of millennia of selective breeding. Very Short Answer Type Questions. The cocoon is made of a thread of raw silk from 300 to about 900 m (1,000 to 3,000 ft) long. Students have a chance to observe complete life cycles of insects from eggs to larvae to pupae to moths. 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