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www.GOALias.blogspot.comOccupational hazardWool industry is an importantmeans of livelihood for many peoplein our country. But sorter’s job isrisky as sometimes they get infectedby a bacterium, anthrax, whichcauses a fatal blood disease calledsorter’s disease. Such risks faced byworkers in any industry are calledoccupational hazards.Boojho is wondering why ithurts when someone pulls hishair but not when he goes for ahaircut.your mother/aunt/grandmother thekind of silk saris they have. List thekinds of silk.Before we discuss the process ofobtaining silk, it is necessary to know theinteresting life history of the silk moth.Life history of silk mothThe female silk moth lays eggs, fromwhich hatch larvae which are calledcaterpillars or silkworms. They grow insize and when the caterpillar is ready toenter the next stage of its life historycalled pupa, it first weaves a net to holditself. Then it swings its head from sideto side in the form of the figure of eight (8).During these movements of the head,the caterpillar secretes fibre made of aBoojho is wondering why acotton garment cannot keep usas warm in winter as a woollensweater does.(a) Male (b) FemaleAdult silk mothsActivity 3.4Debate amongst your classmateswhether it is fair on the part of humansto rear sheep and then chop off theirhair for getting wool.3.2 S3.2 SILKSilk fibres are also animal fibres.Silkworms spin the ‘silk fibres’. Therearing of silkworms for obtaining silkis called sericulture. Find out from(c) Eggs on mulberry leaves (d) Silkworm(e) Cocoon (f) Cocoon with developing mothFig. 3.9 (a to f ) Life history of silk moth28SCIENCE