Students can go through AP State Board 7th Class Science Notes Chapter 3 Animal Fibre to understand and remember the concept easily.
AP State Board Syllabus 7th Class Science Notes Chapter 3 Animal Fibre
→ The making of silk or silk fabrics is a very interesting story.
→ Eggs of silk moth are called ‘Seeds’.
→ Silkmoth is like a butterfly.
→ People buy these silk moths to produce eggs. These centres are called Grinages’.
→ Silkworms eat mulberry leaves day and night.
→ Caterpillar weaves a net to hold itself.
→ Caterpillar moves its moth from side to side and secrets fibre like substance.
→ The cocoons have to be stifled to kill the larva inside as otherwise, it will cut its way out after growing into a moth and spoil the cocoon.
→ Caterpillar of silkworm spins fibre which is mainly made up of two types of protein (Sirisine and fibroin) and is very strong.
→ The thread you get from the average cocoon ranges from about 1,000 to 3,000 feet.
→ The hair of the camel that lives in Rajasthan is not the same as the Angora goat that lives in Kashmir.
→ Woollen fibres are bleached and then dyed with different colours.
→ By making knots with loops and rings of long threads of yarn, woollen fabrics are knitted.
→ Wool is a poor conductor of heat.
→ Animal fibres are natural fibres.
→ Animal fibre is a protein while plant fibre is a carbohydrate.
→ The rearing of silkworms for obtaining silk is called sericulture.
→ Egg, Larva, Pupa, Adult moths are the stages in the life cycle of silkworms.
→ The separation of silk fibre from the cocoon is called reeling.
→ Hair of animals like goats, sheep, camels etc., are used to obtain woollen fibre.
→ Angora goat hair is soft to spin different types of fabrics like shawls and sweaters.
→ Removing hair or fleece from the skin of sheep is called shearing.
→ Cleaning of fleece with a stream of water is called scouring.
→ Knitting is the process of making fabric by using knitting needles to form interlocking loops and rings of woollen yarn.
→ Animal fibre: A product made from animal material
→ Silkworm: Stocky creamy-white Asiatic moth found almost entirely under human care; the source of most of the silk commerce
→ Cocoon: A protective case of silk or similar fibrous material spun by the larvae of moths and other insects that serves as a covering for their pupal stage.
→ Mulberry: Any of several deciduous trees of the genus Moms, having unisexual flowers in drooping catkins and edible multiple fruits.
→ Sericulture: Raising silkworms in order to obtain raw silk
→ Bombyx mon: Chinese silkworm moth
→ Reeling: Obtaining silk from the cocoon
→ Fleece: The coat of wool of a sheep or similar animal.
→ Shearing: Removing by cutting off or clipping
→ Scouring: To remove dirt or grease from (cloth or fibres) by means of a detergent.
→ Knitting: Needlework created by interlacing yarn in a series of connected loops using straight eyeless needles or by machine.
→ Bleaching: To remove the colour from, as by means of chemical agents or sunlight.
→ WeavIng: To construct by interlacing or interweaving strips or strands of material.
→ Dyeing: To colour (a material), especially by soaking ¡n a colouring solution.
→ Warp: To arrange (strands of yarn or thread) so that they run lengthwise in weaving.
→ Woof: The threads that run crosswise in a woven fabric, at right angles to the warp threads.
→ Apart from Mulberry, Tasar silk (Desali Pattu) is produced in our State. Some species of silk moths that lay eggs on the Terminalia oak plantation produce Tasar silk. Mostly tribal people rear this kind of cocoons. This silk plantation is mainly concentrated in Ananthapuram, East Godavari and Visakhapatnam and coastal regions of A.P.
→ The thread you get from the average cocoon ranges from about 1,000 to 3,000 feet, and about 2,000 to 3,000 cocoons are required to make 500 gm of silk. That is about 50,00,000 feet or more than 1,000 miles! That’s not all. People involved in the process suffer from skin as well as respiratory problems due to the continuous handling of the silkworm and the silk fibres.
→ Wool is a poor conductor of heat. Air trapped in between the woollen fibres and our body prevents the flow of heat from our body to our surroundings. So we feel hot and are protected from cold. Give reasons. The woollen cloth also helps to douse the fire.
→ William Harvey:
- Dr William Harvey was regarded as a medical detective for the mystery that he solved viz ‘How does blood move in the human body.
- He was responsible to lay the foundation ‘of Modern Physiology.
- Harvey was born at Folkstone on ¡st April 1578.
- Harvey observed that the heart in a living béing moves up and down, functions as a pump, arteries pulsate synchronously with /he heartbeat.
- At the age of 68, he died. An oration on his name was instituted. The Harvey oration is still delivered annually.