Answer: Option A. ->
:

Answer:1 Mark 
Reason for shearing being helpful: 1 Mark each
Shearing is generally carried out in summer so that the sheep do not suffer from heat strokes in the summer.
Annual shearing of the sheep is an absolute must for the following reasons:

1. Long fleece can become dirty, drag along the ground, increasing the possibility of flystrike. 


2. A bulky fleece decreases the mobility of sheep.


3. Sheep can become susceptible to heat stress during hot weather.


4. Appropriate growth of fleece helps to maintain their body temperature.

Answer: Option D. -> sheared
:
D
Scouring is the process of washing the sheared hair. Shearing is the first step in the processing of wool.
After shearing, the woolen fibres are thoroughly washed in big tanks to remove grease, dust, and dirt with the help of machines.

Answer: Option A. -> reeling
:
A

The process of taking out threads from the cocoon for obtaining silk is called reeling of silk. Reeling is done in special machines, which unwind the threads or fibres of silk from the cocoon after boiling the cocoons.

Answer: Option B. -> False
:
B
Actually, silkworms are not worms, but the larvae or caterpillars hatched from the eggs of the silk moth.
The silk moth passes through the larva and pupa stages during its development after hatching from the egg and forms an adult silk moth.

Answer: Option A. -> True
:
A

Caterpillar completely covers itself by silk fibres. This covering is known as cocoon.

Answer: Option D. -> reeling
:
D

The process of taking out threads from the cocoon for use as silk is called reeling the silk.
Rearing of silk is followed by reeling.

Answer: Option D. -> Sheep, goat and yak
:
D
Wool and silk fibres are obtained from animals. Wool can be obtained from sheep, angora goat, yak, llama, alpaca, and even camels. Silk is obtained from cocoons of silkworm.

Answer: Option A. -> Wool
:
A and B
Fibres obtained from animals are called animal fibres.
Examples:
1. Wool - obtained from the hair of animals like sheep,yak, alpaca, etc.
2. Silk - obtained from the cocoons of silkworm.
Fibres obtained from plants are called plant fibres.
Examples:
1. Cotton - obtained from the seeds of cotton plant.
2. Jute - obtained from stem of jute plant.
Plant fibres and animal fibres are collectively known as natural fibres.

Answer: Option A. -> fleece of sheep
:
A
Wool is an animal fibre obtained from the fleece of animals like sheep, goats, camels, alpacas, llamas and yaks.
 
Silk is also an animal fibre. It is obtained from the cocoons of silkworms.
However, jute and cotton are plant fibres. Jute is obtained from the stem of the jute plant while cotton is obtained from the seeds of cotton plants.

Answer: Option A. -> Silk
:
A, B, and D
Fibres obtained from plants and animals are known as natural fibres.
For example:
$\bullet$ silk- obtained from silkworms.
$\bullet$ wool- obtained from sheep.
$\bullet$ cotton- obtained from cotton plant. 
However, rayon is a semi-synthetic fibre prepared by the chemical treatment of cellulose.