TS 7th Class Science Important Questions 3rd Lesson Silk-Wool

These TS 7th Class Science Important Questions 3rd Lesson Silk-Wool will help the students to improve their time and approach.

TS 7th Class Science Important Questions 3rd Lesson Silk-Wool

Question 1.
Name any two animals from which we obtain fibres. from which parts of those animals, fibres are extracted? Is obtaining fibres from plants and animals similar?
Answer:

• Silk is obtained from silk moth and wool is obtained from sheep.
• No. The way of obtaining fibres from animals differs from that of plants.
• Silk libro is obtained from cocoons. Woollen fibre is obtained from hair of certain animals like sheep.

Question 2.
What is ‘Bombyx Mon’?
Answer:
Silk moths are like butterflies. The other names for them are : ‘Chilakalu’ and ‘Bombyx Mon’.

Question 3.
What are Grinages’?
Answer:
Silk moth selling centres are called “Gninages”.

Question 4.
What is a Cocoon’? or How a Cocoon is built?
Answer:

• A silky, closed nest like structure made by the larva of silk moth is called cocoon.
• Larva of silk moth secretes saliva around its body.
• The saliva becomes like thread due to atmospheric air and heat
• Larva spins the thread around its body. It looks like air tight sack. Thus cocoon is formed.

Question 5.
How is ‘Tasar silk’ produced?
Answer:
Some species of silk moths lay eggs on oak (oak is a large tree of temperate forests). The silk obtained from them is called Tasar silk.

Question 6.
The silk fibre is mainly made up of two types of proteins. What are they?
Answer:
SIRISINE and FIBROIN proteins.

Question 7.
What is ‘reeling’ ? How is it done?
Answer:

• Obtaining silk fibre from cocoon is called ‘reeling’.
• Reeling is done with special machines called as ‘reelers’ and ‘twisters’.

Question 8.
What other products are made from silk?
Answer:
Silk is used to make other products also, like ‘satin’ and ‘crepe’.

Question 9.
What is fleece? A protein or a carbohydrate?
Answer:
Fleece (or fur) is mainly a protein.

Question 10.
Where do we find sheep or goat that give us wool?
Answer:
In Jammu & Kashrnir, Himachal Pradesh, Uttaranchal, Arunachal Pradesh, Sikkim, Haryana, Punjab, Rajasthan and Gujarat we find sheep or goat that give us wool.

Question 11.
Why is shearing done during spring season?
Answer:
Spring is the season of the year that comes between winter and summer.
When the wool is removed from the body of the sheep, the animal cannot bear the severe winter and the hot summer. So shearing is not done in these seasons. It is done in spring, a pleasant season.

Question 12.
What is ‘wool classing (or sorting)?
Answer:
After washing and drying, ‘wool classing’ is done. The wool is sorted into the following categories:

• Soft wool
• Coarse wool
• Broken fibres
• Long fibres
• Unwanted materials like twigs or bits of leaves, etc. This process of separation is called ‘wool classing’.

Question 13.
How the woollen fibres have different colours?
Answer:
Woollen fibres are bleached and then dyed with different colours. So, they have different colours.

Question 14.
What is carding of wool?
Answer:
The bleached and dyed fibres of wool are combed. Wool is pulled through many teeth of the combing machine. The process is called, ‘carding or combing’ of wool.

Question 15.
Describe the process of ‘spinning of wool’.
Answer:
After combing, a machine rolls and pulls the wool fibre out into a thick rope and still another pulls and twists it into a long thread. This is the process of ‘spinning of wool’.

Question 16.
Why is it easy to knit wool?
Answer:
Wool can be knit easily because it has a natural bend or crimp on it.

Question 17.
How are woollen fabrics knitted?
Answer:

• Woollen fabrics are knitted, using needles.
• By making knots with loops and rings of long threads of yarn, woollen fabrics are knitted.

Question 18.
How does silk fibre differ from cotton fibre, chemically?
Answer:
Silk is mainly a protein. Cotton is a carbohydrate, called cellulose.

Question 19.
What do the silkworms eat?
Answer:
Mulberry leaves.

Question 20.
What type of change takes place in the cocoon?
Answer:
Silkworm changes into a moth.

Question 21.
Which process helps us to store the cocoon for a long time?
Answer:
Stiffling.

Question 22.
Which process is done in wool reeling centres?
Answer:
Stiffling.

Question 23.
What are the health hazards faced by people involved in ‘sericulture?
Answer:
Skin and respiratory problems.

Question 24.
How can you classify your doubts about weaving of clothes?
Answer:

• How was weaving done in olden days?
• What type of mach variety is available for weaving clothes at present?
• Can we see small weaving machines for making of small clothes like towels?
• Which clothes are durable ? Hand woven clothes or machine woven clothes?

Question 25.
If silk moths were not domesticated, what would have happened?
Answer:

• At present silk industry has been developed utmost
• The cost of silk fibre is much high. The clothes made of silk have much priority in Indian culture.
• So, if silk moths were not domesticated, we would have lost the wonderful natural fibre which adds more value to the clothes.
• Material used for parachutes, ropes, curtains etc would not have been gotten rigidity.

Question 26.
i. Prarntha is suffering from fever. She went to a doctor. To know the temperature. the doctor made a jerk to the clinical thermometer? Why do the doctor do so?
ii. What are the two types of scales, mention the maximum and minimum readings marked on the clinical thermometer?
Answer:
i. Doctors jerk the clinical thermometer before testing the temperature of the patient because it returns the mercury or other liquid to the neutral point, so that the next reading will be accurate and not effected by the previous one.
ii. There are two types of scales marked on the clinical thermometer.

• One scale starts with 35 degrees (35°) and ends with 45 degrees (45°) in Celsius scale. 35°C – 45°C
• The other scale starts with 94 degrees (94°) arid ends at 108 degrees (108°) in the Fahrenheit scale. 94°F — 108F.

Question 27.
Write the observations you made at the silk, cotton and woollen fibres.
Answer:
Silk, cotton and wool are natural fibres.
Their surface is rough and irregular. When silk is burnt, it gives a smell of feather.
When cotton fibres are burnt, they turn into ash.
Wool also gives feather smell on burning.

Question 28.
Write the information about famous silk rearing centres located in Telangana and Andhra Pradesh states.
Answer:
Silk rearing centres in Telangana and Andhra Pradesh:
Pochampally. Dharmavaram, Madanapalli, Palamaneru, Kadiri, Rayachoti etc.
Tasar silk is produced in the districts such as East Godavari, Visakhapatnam etc.

Question 29.
Draw the Life cycle of silk moth. What is the stage at which we get silk fibre?
Answer:
Egg : Adult silk moth lays about 300-500 eggs on the leaves of mulberry plants.
These eggs are collected by farmers and stored till required. Eggs develop into caterpillar larva.

Caterpillar : These caterpillars feed on mulberry leaves arid grow to full size in one month. During this lime it feeds voraciously and grows in size. The larva is covered with a tough covering which interferes with the elongation of body during the growth. Hence, the caterpilliar makes a hole in the body covering and comes out of the old covering.  develops a new covering. This process is called Molting.

Cacoon : After the completion of growth period, larva stops feeding and starts spinning a silk covering around its body. This is called Cocoon and this stage is called Pupal stage.

Metamorphosis : Once cocoon formation is completed (it takes 48 hrs.), the larva – which is inside the cocoon undergoes changes and becomes a moth. This process is called Metamorphosis.

Question 30.
What care is taken by you during summer in case of wearing clothes? Write their advantages?
Answer:

• Usually it is preferable to wear light coloured cotton clothes during summer.
• Cotton clothes bring cool sensation to the body.
• They absorb the sweat secreted on the skin.

Choose the correct answer :

I. Conceptual Understanding

Question 1.
Silk is obtained from ( )
A) camel
B) sheep
C) cocoon
D) plant
Answer:
C) cocoon

Question 2.
The silk worms are fed on ( )
A) tea leaves
B) mulberry leaves
C) reepal leaves
D) flax
Answer:
B) mulberry leaves

Question 3.
Cocoons are boiled ( )
A) to kill larva
B) to get quality fibre
C) to loosen the fibre
D) All of them
Answer:
D) All of them

Question 4.
Shearing is done during ( )
A) summer
B) winter
C) spring
D) monsoon
Answer:
C) spring

Question 5.
Separation of wool from sheep is ( )
A) shearing
B) scouring
C) knitting
D) bleaching
Answer:
A) shearing

Question 6.
The quality wool is obtained from ( )
A) Moonga sheep
B) Tasar sheep
C) Merino sheep
D) Andhra sheep
Answer:
C) Merino sheep

Question 7.
Killing cocoons of silk is called ( )
A) knitting
B) sorting
C) shearing
D) stifling
Answer:
D) stifling

Question 8.
Bombyx Mon” is a ( )
A) sheep
B) silk moth
C) cotton plant
D) all the above
Answer:
B) silk moth

Question 9.
Selling centre of silk worm eggs is ( )
A) grinages
B) reelirigs
C) woollen centres
D) stiffingers
Answer:
A) grinages

Question 10.
The silk fruit is called ( )
A) red
B) wool
C) cocoon
D) cotton
Answer:
C) cocoon

II. Asking Questions and Making Hypothesis

Question 11.
Find the odd one out ( )
A) wool
B) moonga
C) fleece
D) fur
Answer:
B) moonga

Question 12.
This state is not famous for wool ( )
A) Andhra Pradesh
B) Jammu & Kashmir
C) Himachal Pradesh
D) Ilaryana
Answer:
A) Andhra Pradesh

Question 13.
One of the following is not produced from silk. ( )
A) satin
B) crape
C) parachute
D) shawls
Answer:
D) shawls

Question 14.
Tie and dye silk : Jamadam:: wool . ( )
A) Monga sheep
B) Merino sheep
C) Gujarath sheep
D) Tasar sheep
Answer:
B) Merino sheep

III. Experimentation and Field investigation

Question 15.
Boiling of cocoon in hot water helps in ( )
A) easy extraction of fibres
B) easy killing of worms
C) removal of protein
D) removal of dust
Answer:
A) easy extraction of fibres

Question 16.
The physical appearance of sheep fur……….. ( )
A) thin
B) long
C) smooth to touch
D) All the above
Answer:
D) All the above

Question 17.
Suppose you were asked to clean the fleece of sheep. What process should be followed? ( )
A) Knitting
B) Scoring
C) Shearing
D) Carding
Answer:
C) Shearing

IV. Information Skills and Projects

Question 18.
Naturally woollen industry is very famous in states of India.
A) only western
B) only southern
C) northern and north eastern
D) All
Answer:
C) northern and north eastern

Question 19.
Silk seed development society is located in ( )
A) Gujarath
B) Horsley hills
C) Papikondalu
D) Red hills
Answer:
B) Horsley hills

V. Communication through Drawing and Model Making

Question 20.
Find out the organism and give the stage of life history ( )

A) Larval stage of silk worm
B) Caterpillar stage cockroach
C) Pupa of silkworm
D) Imago of silkworm
Answer:
A) Larval stage of silk worm

Question 21.
Fill in the blank with suitable word to give complete meaning of the flow chart about life history of silk worm. ( )
Egg → Larva → Imago
A) Pupa
B) Cocoon
C) A & B
D) Caterpillar
Answer:
C) A & B

VI. Application to Daily Life and Concern to Bio Diversity

Question 22
silk sarees are designed with beautiful dots and broad borders. ( )
A) Gadwaal
B) Chirala
C) Pochampally
D) Dharmavaram
Answer:
D) Dharmavaram

Question 23.
Silk city is ( )
A) Dharrnavaram
B) Pochampally
C) Adilabad
D) Nellore
Answer:
B) Pochampally

Question 24.
Suppose you planned to visit Dal lake area in Kashmir in winter. What type of clothes you should bring? ( )
A) Woollen
B) Cotton
C) Silk
D) B & C
Answer:
A) Woollen