The DAV Class 7 Science Book Solutions and DAV Class 7 Science Chapter 14 Question Answer – Fabric from Fibre are essential study tools for DAV public school students in Class 7.
DAV Class 7 Science Ch 14 Question Answer – Fabric from Fibre
DAV Class 7 Science Ch 14 Solutions – Fabric from Fibre
Something To Know
A. Fill in the blanks.
Quiestion 1.
The hairy body coat of sheep and goat is called ________
Answer:
Fleece
Quiestion 2.
Shaving off the body coat of sheep is called ________
Answer:
Shearing
Quiestion 3.
Cleaning of fleece to remove dirt and grease is called ________
Answer:
Scouring
Quiestion 4.
The process of separating hair of different textures from the fleece is called
Answer:
Sorting
Quiestion 5.
The rearing of silkworms to obtain silk is called ________
Answer:
Sericulture
Quiestion 6.
________ is the process of separating silk fibres from cocoons.
Answer:
Reeling
Quiestion 7.
The silk thread is made up of ________
Answer:
Silk fibres
B. Write True or False for the following statements.
1. Synthetic fibres are manufactured in factories.
2. Air is a good conductor of heat.
3. Scouring is the process of removal of fleece of sheep.
4. The process, of twisting of raw and dyed fibre, is known as sorting.
5. Silkworms feed on mulberry leaves.
6. The larvae secrete fine filaments made of protein.
7. Reeling is the process of getting silk fibres from cocoons.
Answer:
1. Synthetic fibres are manufactured in factories. (True)
2. Air is a good conductor of heat. (False)
3. Scouring is the process of removal of fleece of sheep. (False)
4. The process, of twisting of raw and dyed fibre, is known as sorting. (False)
5. Silkworms feed on mulberry leaves. (True)
6. The larvae secrete fine filaments made of protein. (True)
7. Reeling is the process of getting silk fibres from cocoons. (True)
C. Tick (✓) the correct option.
1. The process, of removing fleece along with a very thin layer of dead skin of sheep, is called
(a) Shearing
(b) Scouring
(c) Spinning
(d) Sorting
Answer:
(a) Shearing
2. Which of the following animals does not yield wool?
(a) Sheep
(b) Yak
(c) Camel
(d) Buffalo
Answer:
(d) Buffalo
3. The caterpillars of silkworms feed on
(a) Rose leaves
(b) Teak leaves
(c) Mulberry leaves
(d) Grass
Answer:
(c) Mulberry leaves
4. The egg of a silk moth hatches into a
(a) Caterpillar
(b) Cocoon
(c) Pupa
(d) Larva
Answer:
(a) Caterpillar
5. The process of taking out silk threads from the cocoon is hailed
(a) Reeling
(b) Rearing
(c) Sorting
(d) Scouring
Answer:
(a) Reeling
D. Answer the following questions in brief.
Question 1.
Name three animals whose fleece is used for making woollen fibres.
Answer:
Sheep, yak, angora goat
Question 2.
Name three common varieties of wool.
Answer:
Mohair, Merino, Angora
Question 3.
Give the meaning of the term: ‘sorting’.
Answer:
The process of separating the hairs of different textures from the fleece is called sorting.
Question 4.
Define the term: ‘sericulture’.
Answer:
Rearing silkworm for production of silk is called sericulture.
Question 5.
How is silk fibre obtained from cocoon?
Answer:
Cocoons are kept in boiling water for some time. This helps in separating the silk fibre. After that silk fibre is wound around a spool; through a process called reeling.
Question 6.
Name two countries in which silk is produced on a large scale.
Answer:
India and China.
E. Answer the following questions.
Question 1.
How do woollen clothes keep us warm in winter?
Answer:
Wool is a bad conductor of heat. Woollen clothes trap the heat and don’t allow the body heat to escape. Thus, woollen clothes keep us warm in winter.
Question 2.
Describe the purpose of ‘scouring’ in the production of wool?
Answer:
Purposes of ‘scouring’ are as follows:
- To remove dirt grease from sheared fleece.
- It is cleaned by washing with detergent and hot water.
Question 3.
State the practical uses of the (a) long (b) short yarn threads, obtained during the making of wool.
Answer:
Uses of long yarn: Long yarn is used for knitting sweaters, mufflers, gloves, caps, etc.
Uses of short yarn: Short yarn is used for weaving woollen fabrics which are used for making coat, trousers, jackets, shawls, etc.
Question 4.
Write a short note on ‘rearing of silkworms’.
Answer:
A female moth lays hundreds of eggs which are stored at different temperatures. These eggs hatch to produce larvae. The larvae of silk moth are called caterpillars or silkworms. Silkworms are kept in clean trays and are supplied freshly chopped mulberry leaves. They feed for about 25 – 30 days and grow in size. After growing enormously in size, the caterpillars begin to make cocoon. Cocoon is made up of very thin fibre.
Question 5.
Describe the different stages in the life cycle of a silk moth.
Answer:
Various stages of life cycle of a silk moth are as follows:
Adult Moth: This looks like a moth.
Eggs: The female silk moth lays thousand of eggs. The eggs appear as whitish dots on leaves.
Larva: The eggs hatch into larvae. The larva is also called caterpillar.
Pupa: Once a caterpillar grows to become big, it begins to make a cocoon around itself. This stage is called pupa.
Value Based Question
The villagers of Utkarsh village were very happy when they learnt that their senior citizen, Madam Sevika, was to be honoured by the state government. At the award ceremony, the sarpanch of the village, told the gathering how Madam Sevika had devoted all her life to improve the education, health, sanitation and other basic facilities in the village. He went on to compare her village-centered life with that of a silk caterpillar that develops inside cocoon and helps one and all in getting good quality silk.
Question 1.
List three values that Madam Sevika must have held throughout her life in Utkarsh village.
Answer:
Sacrifice, hard work and dedication to a noble cause
Question 2.
State the role of the silkworms in the production of silk.
Answer:
Silkworms play an important role in the production of silk. They produce silk fibres to make a cocoon around them. During the process of silk formation, they sacrifice their life.
Something To Do
Question 1.
Find out for yourself:
(a) The names of different breeds of sheep found in India and places where they are found.
| Indian breeds of sheep | States |
| Lohi | Rajasthan, Punjab |
| Rampur bushair | Uttar Pradesh, Himachal Pradesh |
| Nali | Haiyana, Punjab, Rajasthan |
| Bakharwal | Jammu & Kashmir |
| Marwari | Gujarat |
| Patanwadi | Gujarat |
(b) The names of different breeds of wool-yielding animals found in different countries.
Answer:
Angora goats: Jammu & Kashmir Yak: Tibet and Ladakh Llamaa and Alpaca: South America Camel: Deserts of India, Middle East, Ladakh, etc.
(c) About the hazards of working wool and silk industry.
Answer:
Sorter’s disease affects the workers in wool industry. This is an infection by the bacterium anthrax.
Question 2.
Find out the names of different varieties of silk made in India. Also find the names of traditional silk sarees woven in different parts of our country.
Answer:
Mooga silk, tassar silk Traditional silk sarees: Banarasi saree, Kanjivaram saree, patola, etc.
Question 3.
Mark these places, along with the name of silk saree, on a political map of India.
Answer:
Do it yourself.
DAV Class 7 Science Chapter 14 Solutions – Fabric from Fibre
I. Fill in the blanks.
Quiestion 1.
The under-fur of sheep is called ________
Answer:
called Fleece
Quiestion 2.
Silk fibre is made up of ________
Answer:
Protein
Quiestion 3.
Caterpillar of silk moth feeds on ________
Answer:
Mulberry leaves
Quiestion 4.
Bushair is a breed of ________
Answer:
Sheep
Quiestion 5.
Colouring of fibres is called ________
Answer:
Dyeing
II. Arrange the following steps in the correct sequence of the respective process.
1. Scouring, rearing of sheep, dyeing, shearing, spinning, sorting.
2. Cocoon, eggs, silk moth, caterpillar.
Answer:
1. Rearing of sheep, shearing, scouring, sorting, Dyeing, Spinning
2. Silk moth, eggs, caterpillar, cocoon.
III. Tick (✓) the correct option.
1. Which of these animals is the main source of wool?
(a) Sheep
(b) Camel
(c) Yak
(d) Goat
Answer:
(a) Sheep
2. How many yarns are used in knitting?
(a) One
(b) Two
(c) Three
(d) Four
Answer:
(a) One
3. What is the biological name of silk moth?
(a) Apis indica
(b) Bombyx mori
(c) Apis cerana
(d) Blatta Americana
Answer:
(b) Bombyx mori
4. Which is the largest producer of wool in the world?
(a) India
(b) China
(c) Australia
(d) America
Answer:
(c) Australia
5. Which is the largest producer of silk in the world?
(a) India
(b) China
(c) Australia
(d) USA
Answer:
(b) China
IV. Answer the following questions in brief.
Question 1.
What do you understand by shearing?
Answer:
The process of removal of fleece along with a very thin layer of dead skin is called shearing.
Question 2.
What do you understand by sorting of wool?
Answer:
The process of separating hairs of different textures is called sorting.
Question 3.
What is scouring of wrool?
Answer:
The fleece is washed in large tanks with the help of machines; to remove dirt and grease. This process is called scouring.
Question 4.
How is silk obtained from cocoons?
Answer:
The cocoons are collected and exposed to steam. This separates the silk fibre. Silk fibre is spun around a spindle and the process is called reeling.
Question 5.
What is fibre?
Answer:
A thin continuous strand of a matter is called fibre.
V. Answer the following questions.
Question 1.
What is the role of (i) scouring (ii) sorting during the process of making wool from fleece?
Answer:
Scouring is done to remove grease and dirt from fleece. Sorting is done to separate wool of different textures.
Question 2.
Name some animals whose fleece is used for making woollen fibres. Which of these is used more often?
Answer:
Sheep, camel, goat, angora goat, etc. are some animals whose fleece is used for making woollen fibres. Sheep is the most often used animal for obtaining wool.
Question 3.
Name two countries in which silk is produced on a large scale.
Answer:
India and China.
VI. Projects
Question 1.
Make a list of wool producing states of India.
Answer:
Do it yourself.
Question 2.
Collect pictures of various stages of production of wool. Make a flow chart by using these pictures.
Answer:
Do it yourself.