Chapter 3: Fibre to Fabric

  Science

  (www.olympiadsuccess.com)

Chapter 3: Fibre to Fabric

  Class VII 

  Multiple Choice Questions

 

Question 1

The rearing of silkworms for obtaining silk is called

(a) cocoon

(b) silk

(c) sericulture

(d) silviculture

 

Answer

(c)

 

Question 2

Which of the following is not a type of silk?

(a) Mulberry silk

(b) Tassar silk

(c) Mooga silk

(d) Moth silk

 

Answer

(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

(c) Animal fur cap

(d) Leather jacket

Answer

(a)

 

Question 4

Silk fibre is obtained from

(a) fleece of sheep

(b) cotton ball

(c) cocoon

(d) shiny jute stalk

Answer

(c)

 

Question 5

Wool fibre cannot be obtained from which of the following?

(a) Goat

(b) Llama

(c) Alpaca

(d) Moth

Answer

(d)

 

Question 6

Selective breeding is a process of

(a) selecting the offsprings with desired properties.

(b) selecting the parents with desired properties.

(c) selecting an area for breeding.

(d) selecting fine hair for good quality wool.

Answer

(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.

(c) washing of sheep fibre to remove grease.

(d) rolling of sheep fibre into yarn.

Answer

(a)

 

Question 8

The term sericulture is used for

 

(a) culture of bacteria.

(b) rearing of silkworm.

(c) making silk fabric from silk yarn.

(d) production of sarees.

Answer

(b)

 

Question 9

Reeling of silk is

(a) a process of making silk reels.

(b) spinning of silk fibres.

(c) weaving of silk cloth.

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

Answer

(d)

 

Question 10

Silkworms secrete fibre made of

(a) fat

(b) cellulose

(c) protein

(d) nylon

Answer

(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 _________.

(c) Wool yielding animals bear _________ on their body.

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

Answer

(a) silk, wool (b) cocoons, moth  (c) hair (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.

(c) The rearing of silkworms for obtaining silk is called

silviculture.

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

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

 

Answer

(a) True

(b) False, generally sheep are reared.

(c) False, it is sericulture.

(d) True

(e) False, used to make woollen fabric.

 

Question 13

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

Answer

Hair traps a lot of air, which is a poor conductor of heat.

 

Short Answer Questions

 

Question 14

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

 

Answer

(a) (iii); (b) (iv); (c) (ii); (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.

Answer

Correct sequence 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

(c) BELMURRY

(d) RINGLEE

Answer

. (a) sericulture (b) silkworm (c) mulberry (d) reeling

Question 17

Figure 3.1 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.

 

Fig. 3.1

 

Answer

Yak, Camel, Sheep

Question 18

Write a caption for each of the figures given as Figure 3.2 (a–d).

 

  Fig. 3.2

Answer

(a) Eggs of silk moth on mulberry leaves

(b) Silkworm

(c) Cocoon  

(d) Cocoon with developing moth

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) Fibers are taken out from the cocoon.

(c) After 25 to 30 days, the caterpillars stop eating and start spinning cocoons.

(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.

 

Answer

Correct order – (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.

 

 

Answer

(a) (iii); (b) (i); (c) (ii); (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)____.

 

Answer

(a) female (b) eggs (c) larvae (d) caterpillars (e) silkworms (f) pupa (g) cocoon

 

Question 22

Paheli went to the market to buy sarees for her mother. She took out a thread from the edge of the two sarees 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 saree and which one from a pure silk saree? Give reason for your answer.

Answer

The thread which burns with a smell of burning hair is from pure silk. Silk and hair are protein fibres. Cotton and paper both are carbohydrates, and on burning they give similar smell.

 

Question 23

Explain the phrase – "Unity is Strength" on the basis of the making of fabric from fibre.

Answer

Hint: Fabric needs more energy to tear apart as compared to a single fibre.

 

Question 24

Write various steps for processing fibres into wool.

Answer

Hint: Write briefly about (i) shearing, (ii) scouring, (iii) sorting (iv) picking out of burrs from the hair, (v) dyeing of fibres, (vi) straightening, combing of fibres and rolling into yarm.

 

Question 25

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

Answer

Hint: Trace life history of silk moth from eggs – larvae – pupa – moth