Chapter 3 Fibre To Fabric

Question 1. The rearing of silkworms for obtaining silk is called

(a) cocoon

(b) silk

(c) sericulture

(d) silviculture

Question 2. Which of the following is not a type of silk?

(a) Mulberry silk

(b) Tassar silk

(c) Mooga silk

(d) Moth silk

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

Question 4. Silk fibre is obtained from

(a) fleece of sheep

(b) cotton ball

(c) cocoon

(d) shiny jute stalk

Question 5. Wool fibre cannot be obtained from which of the following?

(a) Goat

(b) Llama

(c) Alpaca

(d) Moth

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.

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.

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.

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.

Question 10. Silkworms secrete fibre made of

(a) fat

(b) cellulose

(c) protein

(d) nylon

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.

Question 12. State whether the following statements are True or False. If false, write the correct statements.

(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.

Question 13. How do the hair of certain animals help in keeping their bodies warm?

Question 14. Match the items of Column I with the items given in Column II.

Column I Column II

(a) Scouring (i) Yields silk fibres

(b) Mulberry leaves (ii) Woolly hair removed

(c) Yak (iii) Food of silk worm

(d) Cocoon (iv) A wool yielding animal

(e) Shearing (v) Cleaning of sheared wool

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.

Question 16. Some words related with silk are jumbled up. Write them in their correct form.

(a) TURECULRISE

(b) WILSMORK

(c) BELMURRY

(d) RINGLEE

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.

Question 18. Write a caption for each of the figures given as Figure 3.2 (a–d).

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.

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.

Column I Column II

(a) Coarse hair (i) Blankets

(b) Fine soft hair (ii) Sweaters

(c) Dead hair (iii) Carpets

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)____.

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.

Question 23. Explain the phrase – “Unity is Strength” on the basis of the making of fabric from fibre.

Question 24. Write various steps for processing fibres into wool.

Question 25. Describe the life history of silk moth with the help of figures of various stages.

Question 20. Boojho, Paheli and their friend Golu were provided with a test tube each containing China rose solution which was pink in colour. Boojho added two drops of solution ‘A’ in his test tube and got dark pink colour. Paheli added 2 drops of solution ‘B’ to her test tube and got green colour. Golu added 2 drops of solution ‘C’ but could not get any change in colour. Suggest the possible cause for the variation in their results.

Question 21. Fill in the cross word given as Figure 5.2 with the help of the clues provided.

Across

(2) The solution which does not change the colour of either red or blue litmus.

(4) Phenolphthalein gives pink colour in this type of solution.

(7) Colour of blue litmus in lemon juice.

Down

(1) It is used to test whether a substance is acidic or basic.

(3) It is a natural indicator and gives pink colour in basic solution.

(5) Nature of ant’s sting.

(6) It is responsible for increase in temperature during a neutralisation reaction.

Question 22. A farmer was unhappy because of his low crop yield. He discussed the problem with an agricultural scientist and realised that the soil of his field was either too acidic or too basic. What remedy would you suggest the farmer to neutralise the soil?

Question 23. You are provided with four test tubes containing sugar solution, baking soda solution, tamarind solution, salt solution. Write down an activity to find the nature (acidic/basic/neutral) of each solution.

Question 24. You are provided with three test tubes A, B and C as shown in Figure 5.3 with different liquids. What will you observe when you put

(a) a piece of blue litmus paper in each test tube.

(b) a piece of red litmus paper in each test tube.

(c) a few drops of phenolphthalein solution to each test tube.

Question 25. Paheli observed that most of the fish in the pond of her village were gradually dying. She also observed that the waste of a factory in their village is flowing into the pond which probably caused the fish to die.

(a) Explain why the fish were dying.

(b) If the factory waste is acidic in nature, how can it be neutralised?

Question 26. Explain two neutralisation reactions related to daily life situation.