Answer the following Questions :-
1. Write Any two properties of silk.
2. What is Fibre?
3. Describe in brief the procedure to obtain silk yarn from silkworm.
4. How will you process sheep wool after shearing?
5. What is the difference between animal and plant fibre? Give two examples of each.
6. What is Sericulture?
7. What are the methods used in Silk Farming?
8. How does wool help in keeping our body warm?
9. Write the stages in the life cycle of silkworm?
10. What adverse effects are seen on the health of workers in silk industry?
Answers
Answer:
1. Write Any two properties of silk.
Silk is marked by the following properties: low density makes for light and comfortable clothing. high resistance to deformation. good insulation properties / warm in winter, cool in summer.
2. What is Fibre?
A fibre is a thin thread of a natural or artificial substance, especially one that is used to make cloth or rope.
3. Describe in brief the procedure to obtain silk yarn from silkworm.
Piles of cocoons are kept under the sun, boiled or exposed to steam. The warmth causes the silk fibre to separate from the rest of the cocoon. The next step is called reeling the silk, which is the process of delicately unwinding the fibre from the cocoon. Reeling is also done in special machines.
4. How will you process sheep wool after shearing?
When you're shearing the sheep, discard the belly, leg, face, and head fleece. After shearing, lay the wool out on the table and trim off the neck wool, all edges of the fleece, and the sweat locks – the greasy fleece from under and around the tail and legs.
Q1) Write Any two properties of silk.
Two properties of silk :
- Silk is a soft, lustrous and elastic fibre.
- Silk can be dyed in beautiful colours.
Q2) What is Fibre?
Fibres are the threads from which cloths or fabric are made.
Q3) Describe in brief the procedure to obtain silk yarn from silkworm.
The procedures to obtain silk yarn from silkworm are:
- A female moth lays hundreds of eggs. The eggs are stored carefully on strips of cloth.
- Then, the eggs are kept in a suitable temperature. The eggs are suitable conditions of temperature and humidity.
- The Silkworms then eat day and night and enormously in size. After 25 to 30 days, the caterpillars stop eating and move to tiny chamber of bamboo to spin cocoons.
- The Silkworm spins the cocoon inside which develops the Silk Moth.
- The cocoons are are kept under the sun or boiled. The silk fibre separate out.
- Reeling is done in special machines, which unwind the threads or fibres of silk from the coccon.
- The silk fibres are then spun into silk threads, which are woven into silk cloths by weavers.
Q4) How will you process sheep wool after shearing?
The process of sheep woolafter shearing are :
- Scouring : The sheared skin with hair is washed thoroughly in tanks to remove grease, dirt and dust.
- Sorting : The hairy skin is sent to a factory where hair of different texture are separated.
- Burr Picking : The small fluffy fibres called Burrs are picked out from the hair.
- Dyeing : The fibres are be dyed in various colours.
- Rolling : The fibres are straightened, combed and rolled into Yarn.
- Wool : The fibres are made into wool for sweaters.
Q5) What is the difference between animal and plant fibre? Give two examples of each.
Animal Fibre :
- Fibres which are obtained from Animals are known as Animal Fibre.
- Examples : Wool and Silk.
Plant Fibre :
- Fibres which are obtained from Plants are known as Plants Fibre.
- Examples : Cotton and Jute.
Q6) What is Sericulture?
The rearing of Silkworms for obtaining silk is called Sericulture.
Q7) What are the methods used in Silk Farming?
Methods used in Silk Farming :
- Silk Farming starts with the cultivation of silk worms from eggs.
- Then, Silk worm matures and during this time, Cocoons are formed.
- Cocoons are exposed to stream and taken out. This process is known as Reeling the silk.
- Silk fibres are spun into threads which are woven into silk cloths.
Q8) How does wool help in keeping our body warm?
During the winter, we use woolen cloths to keep ourself warm. Wool is a poor conductor of heat and air gets trapped in wool fibres. The air prevents the flow of heat from your body to cold surroundings.
Q9) Write the stages in the life cycle of silkworm?
The stages of Silkworm :
- Eggs
- Silkworm
- Cocoon
- Silk Moth
Q10) What adverse effects are seen on the health of workers in silk industry?
People working in Silk Industry sometimes get infected by a bacterium called Anthrax. It is fatal blood disease. Such adverse effects are seen on the health of workers in silk industry.