Class-7 Science, Chapter-3 Fibre to Fabric , Additional exercises in line with NCERT book / CBSE Syllabus
Chapter 3
Fibre to Fabric
Additional Exercises
Exercises from textbook
Activities/Projects
Additional Exercises
Choose
the correct answer:
1. The process of selecting
parents for obtaining special characters in their offsprings is called:
a. Moriculture
b. Selective breeding
c. Rearing
d. Shearing
2. The under fur of Kashmiri
goat is woven into fine shawls called
a. Pashmina shawls
b. Manila Shawls
c. Haapsalu Shawls
d. Kullu Shawls
3. Which of these breeds of of
sheep gives carpet wool?
a. Lohi
b. Rampur bushair
c. Nali
d. Bakharwal
4. The rearing of silkworms
for obtaining silk is called
a. Cocoon
b. Silk
c. Sericulture
d. Silviculture
5. Which of the following is
not a type of silk?
a. Mulberry silk
b. Tassar silk
c. Mooga silk
d. Moth silk
6. Wool fibre cannot be
obtained from which of the following?
a. Goat
b. Llama
c. Alpaca
d. Moth
d.
7. Silk fibre is obtained from
a. Fleece of sheep
b. Cotton ball
c. Cocoon
d. Shiny jute stalk
8. Silkworms secrete fibre
made of
a. Fat
b. Cellulose
c. Protein
d. Nylon
9. 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.
Match
the column
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A
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B
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Yak
wool
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Common
in Tibet and Ladakh
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Angora
wool
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Angora
goats of Jammu and Kashmir
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Soft
under fur of kashmiri goat
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Pashmina
shawls
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Liama
and Alpaca
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Found
in South America
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Burr
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Small
fluffy fibres of wool.
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Ans-
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A
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B
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Yak
wool
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Common
in Tibet and Ladakh
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Angora
wool
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Angora
goats of Jammu and Kashmir
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Soft
under fur of kashmiri goat
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Pashmina
shawls
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Liama
and Alpaca
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Found
in South America
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Burr
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Small
fluffy fibres of wool.
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Fill
in the blanks:
1. Wool is obtained from the fleece
of sheep or yak.
2. Silk fibres come from
cocoons of the silk moth.
3. The under fur of Kashmiri
goat is woven into fine pashmina shawls.
4. The longer fibres
are made into wool for sweaters and the shorter fibres ae spun and woven
into woollen cloth.
5. The most common silk moth
is the mulberry silk moth.
Give
One Word:
1. The rearing of silkworm for
obtaining silk. Sericulture
2. Larvae that has from the
eggs of the female Silk moth. Caterpillar/ Silkworms
3. The stage in which
caterpillar secretes protein Silk fibre. Pupa/ Chrysalis
4. The outer covering of Pupa.
Cocoon
5. The process of separation
of hairs of different textures in a wool factory. Sorting
6. The process of taking out
thread from the cocoon for use as silk. Reeling
State
whether the following statements are true or false:
The
fur on the body of camel is used as wool. True
The
soft silk yarn is as strong as a comparable thread of Steel. True
Yak
hair are not used to make woollen fabric. False
The
rearing of silkworms for obtaining silk is called silviculture. False
In
the process of obtaining wool from fleece, sorting is done after scouring. True
Select
the odd one
1. Wool yielding animals- Sheep, goat, yak, buffalo
2. Stages of life cycle of
silk moth- Egg, caterpillar, mulberry,
pupa, silkmoth
3. Processing of wool - Shearing, scouring,
sorting, reeling
Some
words related with silk are jumbled up. Write them in
their
correct form.
(a)
TURECULRISE - SERICULTURE
(b)
WILSMORK- SILKWORM
(c)
BELMURRY - MULBERRY
(d)
RINGLEE - REELING
Differentiate
between
Fleece and Cocoon
Fleece
and Cocoon
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Fleece
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Cocoon
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Fleece
is the woolly covering of a sheep or goat.
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Cocoon
is the outer covering of pupa.
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Wools
is obtained from fleece.
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Silk is obtained from cocoon.
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Answer
the following questions:
Q. What do you understand by
‘selective breeding’?
Ans-
The process of selecting parents for obtaining special characters in their
offspring, is termed as ‘selective breeding’.
For
example - Some sheeps have coarse beard hair and soft under - hair close to the
skin while some other sheeps have only soft under-hair. Sheeps with only
fine under-hair are specially chosen to give birth to sheep which have only
soft under-hair.
Q.
What do rearers feed to the sheep?
Ans-
Sheep are herbivorous and prefer grass and leaves. Reares also feed them on the
mixture of pulses, corn, jowar, oil cakes and minerals.
In
winter, sheep are kept indoors and fed on leaves, grain and dry fodder.
Q.
What do you understand by occupational hazards? Which occupational hazard is
associated with wool industry?
Ans-
The risks faced by workers in any industry are called occupational hazards.
In
wool industry, sorters job is risky as sometimes they get infected by a
bacterium, anthrax, which causes a fatal blood disease called sorter’s
disease.
Q.
Draw the life cycle of silkmoth.
Ans-
Give reason. Why?
Q. Animals have a thick coat
of hair on their body.
Ans-
Hairs on the body trap a lot of air. Air is a poor conductor of heat.
Thus, a tick coat of hairs keeps the animals warm.
Exercises
from Textbook
Q.
You must be familiar with the following nursery rhymes:
(i)
‘Baa baa baa sheep, have you any wool.
(ii)
‘Mary had a little lamb, whose fleece was white as snow.’
Answer
the following:
(a) Which parts of the black
sheep have wool?
Ans- Fleece (hairy skin) of the black
sheep has wool.
(b) What is meant by the
while fleece of the lamb?
Ans- The while fleece of the lamb means the
skin of lamb with with hairs.
Q.
The silkworm is (a) a caterpillar, (b) a larva. Choose the correct option.
(i)
a
(ii)
b
(iii)
both a and b
(iv)
a larvae
Choose
the correct option.
Ans- (iii) both
a and b
Q.
Which of the folowing does not yield wool?
(i)
Yak (ii) Camel (iii) Goat
(iv) Wooly dog
Ans- Wooly dog
Q.
What is meant by the following terms?
(i)
Rearing (ii) Shearing (iii) Serriculture
Ans- Rearing- Rearing means the
feeding, taking medical care and breeding of useful animals like sheep, goat
etc.
Shearing- The process of removing skin of sheep
along with a thin layer of skin.
Sericulture- The rearing of silkworms fro for
obtaining silk is called sericulture.
Q.
Given below is a sequence of steps in the processing of wool. Which are the
missing steps? Add them.
Shearing,
___________, sorting, ___________, ___________, ___________
Ans- (i)
Shearing (ii) Scouring (iii) Sorting (iv) Picking out burrs (v) Dying of fibre
(vi) Straightening, combing and rolling of yarn.
Q.
Make sketches of the two stages in the life history of the silk moth which are
directly related to the production of silk.
Q.
Out of the following, which are the two terms related to silk production?
Sericulture,
Floriculture, moriculture, apiculture and silviculture
Hints:
(i) Silk production involves cultivation of mulbery leaves and rearing
silkworms.
(ii)
Scientific name of mulbery is Morus alba.
Ans-
Sericulture and Moriculture
Q.
Match the column I with those given in Column II
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Column I
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Column II
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Scouring
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Yields silk
fibres
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Mulbery
leaves
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Wool yielding
animal
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Yak
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Reeling
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Cocoon
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Food of silk
worm
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Cleaning
sheared skin
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Ans-
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Column I
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Column II
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Scouring
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Cleaning
sheared skin
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Mulbery
leaves
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Food of silk
worm
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Yak
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Wool yielding
animal
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Cocoon
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Yields silk
fibres
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Extended
learning- Activities and Projects
·
Collect
pictures of animals whose hair is used as wool. Stick them in your
scrapbook. if you are unable to get pictures try and draw them.
·
Find
out words for sheep, goat, camel and yak in your local language and also in
other languages of our country.
·
In
the outline map of India, mark the places where you find animals that provide
wool. Use different colours to denote the location of different wool yielding
animals.
·
Find
the maximum length of continuous Silk thread that can be obtained from a
cocoon.
·
Find
out, why caterpillars need to shed their skin when they grow bigger but we
humans do not.
·
Take
the help of your mother, aunt or teacher and identify the types of silk
such as mulberry silk, tasar silk,
eri silk, moonga silk etc.
Compare the texture of these silks with that of artificial silk pieces which
contains synthetic fibres. Try and collect pictures of different moths, whose
caterpillars provide various types of silk.
Given below is a
Crossword Puzzle based on this lesson. Use hints to fill in the blank
spaces with letters that complete the words.
Down (B)
1: washing
2: animal fibre
3: long thread like
structure
Across (A)
1: keep Swarm
2: its leaves are
eaten by silkworms
3: hatches from egg
of moth
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Did
you know?
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(1)
In terms of the number of sheep, India ranks third in the world, behind China and Australia.
However, the New Zealand sheep are
known to yield the best wool.
(2)
Discovery of Silk
The
exact time of discovery of silk is perhaps unknown. According to an old
Chinese legend, the empress
Si-lung-Chi was asked by the emperor Huang-ti to find the cause of the
damaged leaves of mulberry trees growing in their garden. The empress found
white worms eating up mulberry leaves. She also noticed that they are
spinning shiny cocoons around them. Accidentally a cocoon dropped into
her cup of tea and a tangle of delicate threads separated from the cocoon.
Silk industry began in China and was kept a closely guarded secret for
hundreds of years. Later on, traders and travellers introduced silk to other
countries. The route they travelled is still called the ‘silk route’.
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