Multiple Choice Questions
Question 1: The rearing of silkworms for obtaining silk is called
(a) cocoon
(b) silk
(c) sericulture
(d) silviculture
Solution 1: (c) sericulture
The production of silk and breeding and management of silkworm is called sericulture.
Question 2: Which of the following is not a type of silk?
(a) Mulberry silk
(b) Tassar silk
(c) Mooga silk
(d) Moth silk
Solution 2: (d) Moth silk
Among the above given options Moth silk is not any kind of silk rather Mulberry silk, Tassar silk, Mooga silk are different varieties of silk obtained from different kind of silkworms.
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
Solution 3: (a) Woollen shawl
Woollen shawls are made from wool which means hair of sheep, yak, camel, etc. and to obtain wool one does not require to kill the animal. Silk scarf is made from silk which is obtained by killing of silkworm. Animal fur cap is made from fur which is made by killing of animal. Leather jacket is made from leather which is obtained by skin of animal and requires to kill the animal.
Question 4: The silk fibre is obtained from
(a) fleece of sheep
(b) cotton ball
(c) cocoon
(d) shiny jute stalk
Solution 4: (c) cocoon
Silk fibre is obtained from cocoon. Cocoon is present in silkworm.
Question 5: A wool fibre cannot be obtained from which of the following?
(a) Goat
(b) Llama
(c) Alpaca
(d) Moth
Solution 5: (d) Moth
Wool fibre cannot be obtained from Moth. It is a type of insect. Wool fibre can only be obtained from Goat, Llama, Alpaca animal.
Question 6: Selective breeding is a process of
(a) selecting the offspring with desired properties.
(b) selecting the parents with desired properties.
(c) selecting an area for breeding.
(d) selecting fine hair for good quality wool.
Solution 6: (b) selecting the parents with desired properties.
Selective breeding involves opting out desired parents with particular traits. In this process two different variety gets involve to produce their hybrid.
Question 7: The general process that takes place at a sheep shearing shed is
(a) removal of fleece.
(b) separating the hair of different textures.
(c) washing of sheep fibre to remove grease.
(d) rolling of sheep fibre into yarn.
Solution 7: (a) removal of fleece.
Removal of fleece from sheep is known as shearing. Shearing will be done manually by razors or by shearing machines.
Question 8: The term sericulture is used for
(a) culture of bacteria.
(b) rearing of the silkworm.
(c) making silk fabric from silk yarn.
(d) production of sarees.
Solution 8: (b) rearing of the silkworm.
Breeding and management of silkworms for obtaining silk is called sericulture.
Question 9: Reeling of silk is
(a) a process of making silk reels.
(b) the spinning of silk fibres.
(c) the weaving of silk cloth.
(d) the process of taking silk threads from the cocoon.
Solution 9: (d) the process of taking silk threads from the cocoon.
Reeling of silk means getting the threads of silk from the cocoon.
Question 10: Silkworms secrete fibre made of
(a) fat
(b) cellulose
(c) protein
(d) nylon
Solution 10: (c) protein
A silkworm's salivary gland produces an enzyme that is used as silk.
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.
Solution 11:
(a) Silk and Wool fibres are obtained from animals.
(b) Silk fibres come from cocoons of the silk moth.
(c) Wool yielding animals bear hair on their body.
(d) Hair trap a lot of air, which is a poor conductor of heat.
Question 12: State whether the following statements are True or False. If false, correct them.
(a) Silkworms are caterpillars of the 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 is not used to make woollen fabric.
Solution 12:
- True
- False- In India, sheep are reared for wool production.
- False- Sericulture is the rearing of silkworms for silk processing.
- True
- False- Woollen fabric is fabricated from hair of Yak
Question 13: How does the hair of certain animals help in keeping their bodies warm?
Solution 13: Hair are poor conductors of heat, therefore they would not allow the escape of heat from the body, which means their bodies are kept warm.
Short Answer Questions
Question 14: Match the items of Column I with the items given in Column II.
Solution 14:
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 15:
(iii) Shearing
(iv) Scouring
(v) Sorting
(i) Picking out the burrs
(ii) Dyeing in various colours
Question 16: Some words related to silk are jumbled up. Write them in their correct form.
(a) TURECULRISE
(b) WILSMORK
(c) BELMURRY
(d) RINGLEE
Solution 16:
(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.
Solution 17:
(a) Yak
(b) Camel
(c) Sheep
Question 18: Write a caption for each of the figures given as Figure 3.2 (a–d).
Solution 18:
a) Eggs of silk moth on mulberry leaves
b) Silkworm
c) Cocoon
d) Cocoon along 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) Fibres 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.
Solution 19:
(e) Female silk moths lay eggs.
(a) Eggs are warmed to a suitable temperature for the larvae to hatch from eggs.
(d) The larvae/caterpillars or silkworms are kept in clean trays along with freshly chopped mulberry leaves.
(c) After 25 to 30 days, the caterpillars stop eating and start spinning cocoons.
(f) Cocoons are kept under the sun or boiled in water.
(b) Fibers are taken out from the cocoon.
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 20:
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 21: The a) female silk moth lays b) eggs, from which hatch c) larvae called d) caterpillars or e) silkworms. They grow in size and when the caterpillar is ready to enter the next stage of its life history called f) pupa, it first weaves a covering to hold itself, which is known as 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 a reason for your answer.
Solution 22: Cotton is a thread that burns with the scent of burning paper, since both paper and cotton are carbohydrate cellulose and thus burn with a similar odour. Similarly, the thread which is burned with the scent of burning hair is silk since silk, as well as hair, are proteins therefore they burn with a similar characteristic smell.
Question 23: Explain the phrase – “Unity is Strength” on the basis of the making of fabric from the fibre.
Solution 23: The cloth is composed of a thin string called fibres, like hair. Dropping a fibre thread is easy since it is delicate and therefore easy to crack. Fabric, on the other hand, is the aggregation of several fibres of fibre that are difficult to sever and take a large amount of energy to break the fabric. Hence, based on making of cloth from fibre it is said that unity is strength.
Question 24: Write various steps for processing fibres into wool.
Solution 24:
Step I: The sheep's fleece is stripped from its body along with a thin layer of skin [Fig. 3.8 in (a)]. It's called shearing, this process. To cut hair off, devices similar to those used by barbers are used. Typically, during hot weather, the hair is cut. This encourages sheep without their safe coat of fur to survive. Woollen fibres supply the fur. Woollen fibres are then processed for wool processing.
Step II: Hair-sheared skin is vigorously cleaned in tanks to remove grease, dirt and pollen. Scouring is called this. Scouring nowadays is carried out by robots [Fig. 3.8 points (b) and (c)].
Step III: When scouring and sorting is completely done the hair of various textures are separated and sorted in the factories from the hairy skins.
Step IV: The little fluffy fibres are pulled out of the fur, called burrs. This are the same burrs on your sweaters that often surface. The fibres are scoured and dried again. This is the yarn that is prepared to be drawn into fibres.
Step V: As the natural fleece of sheep and goats is black, brown or white, the fibres may be colored in different colours.
Step VI: The fibres are straightened into wool, combed and folded. For sweaters, the longer fibres are made into yarn and the shorter fibres are dyed and woven into woollen fabric.
Question 25: Describe the life history of silk moth with the help of figures of various stages.
Solution 25:
