Lesson: Fibre to Fabric

Multiple Choice Questions

The rearing of silkworms for obtaining silk is called

(a) cocoon

(b) silk

(d) silviculture

Solution:

(c)

Question: 2

Which of the following is not a type of silk?

(a) Mulberry silk

(b) Tassar silk

(d) Moth silk

Solution:

(d)

Question: 3

Paheli wanted to buy a gift made of animal fibre obtained without killing the animal. Which of the following would be the right gift for her to buy?

(a) Woollen shawl

(b) Silk scarf

(d) Leather jacket

Solution:

(a)

Question: 4

Silk fibre is obtained from

(a) fleece of sheep

(b) cotton ball

(d) shiny jute stalk

Solution:

(c)

Question: 5

Wool fibre cannot be obtained from which of the following?

(a) Goat

(b) Llama

(d) Moth

Solution:

(d)

Question: 6

Selective breeding is a process of

(a) selecting the offspring with desired properties.

(b) selecting the parents with desired properties.

(d) selecting fine hair for good quality wool.

Solution:

(b)

Question: 7

The general process that takes place at a sheep shearing shed is

(a) removal of fleece.

(b) separating hair of different textures.

(d) rolling of sheep fibre into yarn.

Solution:

(a)

Question: 8

The term sericulture is used for

(a) culture of bacteria.

(b) rearing of silkworm.

(d) production of sarees.

Solution:

(b)

Question: 9

Reeling of silk is:

(a) a process of making silk reels.

(b) spinning of silk fibres.

(d) the process of taking silk threads from cocoon.

Solution:

(d)

Question: 10

Silkworms secrete fibre made of

(a) fat

(b) cellulose

(d) nylon

Solution:

(c)

Very Short Answer Questions

Question: 11

Fill in the blanks in the following statements.

(a) _________ and _________ fibres are obtained from animals.

(b) Silk fibres come from _________ of silk _________.

(d) Hair trap a lot of _________, which is a poor _________ of heat.

Solution:

(a) Silk, wool

(b) Cocoons, moth

(d) Air, conductor

Question: 12

State whether the following statements are True or False. If false, correct them.

(a) Silkworms are caterpillars of silk moth.

(b) In India, camels and goats are generally reared for obtaining wool.

(d) In the process of obtaining wool from fleece, sorting is done after scouring.

(e) Yak hair is not used to make woollen fabric.

Solution:

(a) True

(b) False. In India, sheeps, camels and angora goats are reared for obtaining wool.

(d) True

(e) False, yak hair is used for making woollen fabric.

Question: 13

How does the hair of certain animals help in keeping their bodies warm?

Solution:

The thick and long hair seen in some animals, such as sheep, yak, etc., help to keep their bodies warm by trapping a lot of air. Air being a poor conductor of heat, doesn’t allow the body warmth to flow out.

Short Answer Questions

Question: 14

Match the items of Column I with the items given in Column II.

Solution:

(a) (iii)

(b) (iv)

(d) (i)

Question: 15

Various steps involved to obtain wool from fleece are given here.

(i) Picking out the burrs

(ii) Dyeing in various colours

(iii) Shearing

(iv) Scouring

(v) Sorting

Write the above steps in the correct sequence in which they are carried out.

Solution:

The correct sequence of obtaining wool from fleece is:

(iii), (iv), (v), (i), (ii)

Question: 16

Some words related with silk are jumbled up. Write them in their correct form.

(a) TURECULRISE

(b) WILSMORK

(d) RINGLEE

Solution:

(a) Sericulture

(b) Silkworm

(d) Reeling

Question: 17

The figure below shows three rings of circles with letters in them. Some of these letters in each ring can form the name of one wool yielding animal. Find the names of these animals.

Solution:

Yak, Camel, Sheep

Question: 18

Write a caption for each of the figures given below:

Solution:

(a) Silk moth eggs on mulberry leaves

(b) Silkworm

(d) Cocoon with a moth developing inside

Question: 19

Steps for the production of silk are given below in a jumbled order. Arrange them in their proper sequence.

(a) Eggs are warmed to a suitable temperature for the larvae to hatch from eggs.

(b) Fibres are taken out from the cocoon.

(d) The larvae/caterpillars or silkworms are kept in clean trays along with freshly chopped mulberry leaves.

(e) Female silk moths lay eggs.

(f) Cocoons are kept under the sun or boiled in water.

Solution:

Correct sequence $-$ (e), (a), (d), (c), (f), (b)

Question: 20

A wholesale woollen fibre dealer gets the woollen fibre of different textures sorted for various purposes. Match the items in Column I with the woollen fibre in Column II.

Solution:

(a) (iii)

(b) (i)

(d) (iv)

Long Answer Questions

Question: 21

Complete the paragraph related to the life history of silk moth by filling in the blanks.

The ____(a)___ silk moth lays ___(b)___, from which hatch____(c)___ called ___(d)____ or ___(e)____. They grow in size and when the caterpillar is ready to enter the next stage of its life history called ___(f)____, it first weaves a covering to hold itself which is known as ___(g)____.

Solution:

(a) Female

(b) Eggs

(d) Caterpillars

(e) Silkworms

(f) Pupa

(g) Cocoon

Question: 22

Paheli went to the market to buy saris for her mother. She took out a thread from the edge of the two saris shown by the shopkeeper and burnt them. One thread burnt with a smell of burning hair and the other burnt with the smell of burning paper. Which thread is from a pure cotton sari and which one from a pure silk sari? Give reason for your answer.

Solution:

The thread that burns giving out a smell of burning hair is of pure silk. Hair and silk are protein fibres, so the smell of burning silk and hair would be similar.On the other hand, the thread which burns with a smell of burning paper is cotton. Since paper and cotton are carbohydrates, on burning they produce a similar smell.

Question: 23

Explain the phrase $-$ “Unity is Strength” on the basis of the making of fabric from fibre.

Solution:

Many fibres are joined or woven together to form a fabric, which is difficult it tear apart. A single fibre can be easily torn apart by hands. Thus, when one is alone he or she can be easily destroyed, while when many are standing together, it becomes difficult to destroy. This is similar to the proverb “united we stand, divided we fall.”

Question: 24

Write various steps for processing fibres into wool.

Solution:

Processing Fibres into Wool: The process follows various steps, such as, shearing, scouring, sorting, cleaning of burrs, dyeing, and rolling into yarn.

(a) Shearing: this is the first step that involves removal of fleece along with the dead uppermost layer of the sheep’s skin. Shearing is usually done in warm weather using mechanical shears.

(b) Scouring: this step involves washing of sheared hair in big tanks to remove dirt, dust, and grease. Washing is done by machines.

(c) Sorting: this step involves separating hairs of different types and textures, while segregating the good from low quality fibres.

(d) Dyeing: after removing all small fluffy fibres or burrs, the next step is dyeing in various colours. The natural fibres are generally in white, brown and black colours, so they are dyed to produce various other colours of wool.

(e) Straightening, Combing, and Rolling into yarn:

After dyeing the fibres undergo straightening, combing, and rolling into yarns, which are then made ready to produce woollen clothes.

Question: 25

Describe the life history of silk moth with the help of figures of various stages.

Solution:

Life Cycle of a Silk Moth:

The life cycle of a silk moth starts with the laying of eggs by the female silk moth. The eggs hatch to produce larvae or caterpillars, which are known as silkworms. The silkworms eat fresh mulberry leaves, and as they grow, they reach the next stage in their lifecycle known as the pupa.

In the pupa stage, the caterpillar starts weaving a net around itself by secreting a protein fibre that hardens when it comes in contact with air. This fibre is known as silk. When the caterpillar is completely covered with the silk fibre it forms the pupa, and this fibrous covering is termed as the cocoon. The moth develops within this cocoon over a period of time. The silk thread used in textiles is obtained from this cocoon.