Silk protein consists of sericin and fibroin mainly. Wool fibre cannot be obtained from which of the following? 1. The GM silkworms secrete fibres made of spider web protein (spider silk), which is stronger than normal silk fibre protein. The Secret of Silk. 10.Silkworms secrete fibre made of Silk has set the standard in luxury fabrics for several millennia. Sericulture, also called silk farming, is the process of making silk fibers. The thread which burns with a smell of burning hair is from pure silk. Explain how this results in slower responses to stimuli. Question 11 The membrane potential at Q was the same whether medium or heavy pressure was applied to the finger tip. The scientists ensured the spider gene was expressed only in cells within the silk glands. The answer lies in how they control the silk protein solubility and structural organization in their glands. There are hundreds of types of silkworms, but the scientific name of the one that produces the finest quality silk is Bombyx mori. (d) In the process of obtaining wool from fleece, sorting is done after scouring. Figure 5 . Here you will learn in-depth about how is silk obtained from silkworm… Steps for the production of silk are given below in a jumbled order. (d) selecting fine hair for good quality wool. (d) production of sarees. A material which is composed of thin and continuous strands is known as fiber. Explain why. The rearing of silkworms for obtaining silk is called Sericulture. Silk worms and silk worm eggs are made of silk. Suggest why. A domesticated silkworm produces a single cocoon in its life cycle, which when unraveled can produce up to 3,000 meters of one strand of silk fibre. (b) separating hair of different textures. 11. Silkworm workers simply unravel the cocoons, each cocoon producing between 325–1,000 feet (100–300 meters) of fine, very strong thread. Osmoreceptors are specialised cells that respond to changes in the water potential of the blood. These questions are design in such a way, it covers all the important questions, intext questions and keywords of the chapter 3 of class 7 Science. Explain the phrase – "Unity is Strength" on the basis of the making of fabric from fibre. ATP is an energy source used in many cell processes. (b) spinning of silk fibres. On issuing into the air, the fine stream is hardened into the silk fiber, which the caterpillar spins into a cocoon. Death was the penalty for telling the secret. She took out a thread from the edge of the two sarees shown by the shopkeeper and burnt them. These solutions for Animal Fibres Wool And Silk are extremely popular among Class 7 students for Science Animal Fibres Wool And Silk Solutions come handy for quickly completing your homework and preparing for exams. Silkworm is an insect that makes silk. (c) Wool yielding animals bear _________ on their body. Fill in the blanks in the following statements. Reeling of silk is (a) a process of making silk reels (b) spinning of silk fibres (c) weaving of silk cloth (d) the process of taking silk threads from cocoon Answer: (d) the process of taking silk threads from cocoon. (b) Silk fibres come from _________ of silk _________. In man-made fibre production the name is applied to the extrusion of a solution to form a fibre, a process similar to the method by which silkworms and similar insect larvae produce filament to make their cocoons from a viscous fluid that they secrete. (d) the process of taking silk threads from cocoon. 9. From around 300 AD, the cultivation of silk reached … Very Short Answer Type Questions. Explain how the resting potential of -70 mV is maintained in the sensory neurone when no pressure is applied. (c) weaving of silk cloth. Various steps involved to obtain wool from fleece are given here. Silk is produced by rearing silkworms in captivity. Hint: Trace life history of silk moth from eggs – larvae – pupa – moth. Silkworms secrete fibre made of … Hair traps a lot of air, which is a poor conductor of heat. The caterpillar/ silkworm secretes fibre made of a protein which gets hardened on being exposed to air and become silk fibre. Match the items of Column I with the items given in Column II. Silkworms secrete fibre made of (a) fat (b) cellulose (c) protein (d) nylon. (c) making silk fabric from silk yarn. Production of silk was confined in the region of China until the opening of Silk Road in the late half of the first millennium BC. Complete the paragraph related to the life history of silk moth by filling in the blanks. Explain why. Within the cocoon the caterpillar is presently transformed into the chrysalis or pupa. The fibers which are obtained from plants and animals are known as natural fibers whereas synthetic fibers are man-made fibers. Soln: The answer is (c) protein. (b) spinning of silk fibres. 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