Solutions to the NCERT textbook questions are a valuable resource for students for their exam preparations as most of the exam questions are based on textbook questions. Thus, to help students with their preparations, Extramarks offers NCERT Solutions for Class 7 Science Chapter 3. These solutions are prepared by subject matter experts who have years of experience in teaching. As the explanations of all the answers are comprehensive, the fundamentals of the chapter are understood by the students in a better way.
Hence, students will find these resources to be very helpful with their preparations, last-minute revisions, and for help with their assignments.
NCERT Solutions for Class 7 Science Chapter 3
Access NCERT Solutions for Class 7 Science Chapter 3 – Fibre to Fabric
NCERT Solutions for Class 7 Science Chapter 3 Fibre to Fabric
The NCERT Class 7 Science Chapter 3 focuses on several aspects of how fibres are transformed into fabric. It talks about the entire lifecycle of how fibre is converted to a piece of fabric. This includes all steps from extracting wool and silk fibres from sheep, goats, yak, and silkworms, to how these are converted to fabric by weavers.
Chapter 3 – Fibre to Fabric
Wool can be extracted from sheep, goats, yak and even camel. Animals of various breeds provide wool of varying quality. Some of the examples of famous wool-yielding animals across the world are; Yak (in Ladakh and Tibet), Angora goat (source of angora wool in Jammu and Kashmir), and Alpaca, and Llama (in South America). The underfur of Kashmiri goats is soft and hence, used for making high-quality Pashmina shawls.
Even though there are numerous sources of wool, sheep are generally raised to assist the wool industry. The sheep's fur is clipped, gathered, and processed to make wool. The breeding and rearing of sheep is the beginning of the process. If you visit the hills in Uttaranchal, Himachal Pradesh, Jammu & Kashmir, Sikkim, and Arunachal Pradesh, you will come across herds of sheep with their shepherds. The wool we wear, shawls and knitted sweaters are the completed product of processing sheep's fleece.
The entire process of converting wool to fabric can be divided into the following steps:
Step 1 Shearing: It is the first step in removing the fleece and a thin layer of skin from a sheep's body. Shearing is carried out with the assistance of machines similar to those used by barbers. Shearers prefer hot weather because it allows the sheep to survive without its protective fur. Woollen fibres are found in the fur hair and are subsequently processed to make woollen yarn.
Step 2 Scouring: After shearing, the shearers vigorously wash the skin and hair in tanks to remove dust, filth, and oil. This process is known as Scouring. Although in the past this task was done manually, now it is completed by machines.
Step 3 Sorting: After scouring, the hair skin is sent to a factory, where hair of different sorts and textures are separated by texture.
Step 4 Picking Burrs: The hairs may contain burrs, which are puffy and tiny fibres, similar to ones found on our sweaters. The fibres of these burrs are scoured again and dried the wool is now ready to be spun into yarn.
Step 5 Dyeing: The natural colours of a goat's or sheep's fleece are white, brown, or black. However, the fibres can be dyed in a variety of colours.
Step 6 Yarn Rolling: After dyeing, the fibres are combed, straightened and rolled into yarn. Long fibres are used in wool for sweaters, while shorter fibres are spun and woven into woollen cloth.
Silk fibre is another form of animal fibre used to produce fibres. Silkworms are the creators of silk fibre. Sericulture is the practice of raising silkworms to produce silk.
The life cycle of a silk moth is fascinating to learn about. The process begins by the female moth laying her eggs. The larvae (also known as silkworms or caterpillars) hatch from the eggs.
As the caterpillar grows in size, it advances to the pupa stage.
The worm weaves a net-like structure to support itself during the pupa stage. Then it makes a figure eight with its head, swinging from side to side (8). During these movements, the caterpillar secretes a fluid that solidifies and becomes the silk thread when it comes into contact with air. The pupa is formed after the caterpillar is completely covered with silk fibre. The scientific term for this silk coating is a cocoon. It's where the worm transitions from pupa to the moth stage. Silk yarn is made from the cocoon of the silkworm.
Exercise 3.2 total Solutions: 16 Questions (9 short questions and 7 long questions)
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Key Features of NCERT Solutions for Class 7 Science Chapter 3
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- NCERT Solutions by Extramarks are prepared by subject matter experts that have years of experience in their respective fields. They give special attention to providing accurate solutions that students can rely on.
- The solutions are drafted in simple and easy-to-understand language so that students have no trouble understanding them.
- These solutions can be used by students for their exam preparations, last-minute revisions, and for any help that they require with their assignments.
- The student can access NCERT Solutions for Class 7 Science Chapter 3 at any time on the Extramarks website or the app.
Q.1 You must be familiar with the following nursery rhymes:
- ‘Baa baa black sheep, have you any wool.’
- ‘Mary had a little lamb, whose fleece was white as snow.’
Answer the following:
- Which parts of the black sheep have wool?
- What is meant by the white fleece of the lamb?
- Wool is obtained from fleece (hair) of sheep.
- White fleece refers to white thick hairy coat of lamb.
Q.2 The silkworm is (a) a caterpillar, (b) a larva. Choose the correct option.
3. both a and b
4. neither a nor b
The correct option is iii. both a and b.
Q.3 Which of the following does not yield wool?
4. Woolly dog
4. Woolly dog
Q.4 What is meant by the following terms?
1. Rearing: Bringing up and looking after farm animals is known as rearing.
2. Shearing: The process of removing the fleece of sheep along with a thin layer of skin is called shearing.
3. Sericulture: Rearing (raising) of silkworms for producing silk is known as sericulture.
Q.5 Given below is a sequence of steps in the processing of wool. Which are the missing steps? Add them.
Shearing, __________, sorting, __________, ___________.
Shearing, scouring, sorting, drying, carding.
Q.6 Make sketches of the two stages in the life history of the silk moth which are directly related to the production of silk.
Q.7 Out of the following, which are the two terms related to silk production?
Sericulture, floriculture, moriculture, apiculture and silviculture.
(i) Silk production involves cultivation of mulberry leaves and rearing silkworms.
(ii) Scientific name of mulberry is Morus alba.
Out of the given terms, those related to silk production are sericulture and moriculture.
Sericulture: Rearing of silkworms for the production of silk is known as sericulture.
Moriculture: Science of mulberry plant cultivation is known as moriculture.
Q.8 Match the words of column I with those given in Column II:
|Column I||Column II|
|1. Scouring||(a) Yields silk fibres|
|2. Mulberry leaves||(b) Wool yielding animal|
|3. Yak||(c) Food of silk worm|
|4. Cocoon||(d) Cleaning sheared skin|
|Column I||Column II|
|1. Scouring||(d) Cleaning sheared skin|
|2. Mulberry leaves||(c) Food of silk worm|
|3. Yak||(b) Wool yielding animal|
|4. Cocoon||(a) Yields silk fibres|
Q.9 Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
|(D)||1: Through Washing||(A)||1: Keeps Warm|
|2: Animal Fibre||2: Its leaves are eaten by silkworm|
|3: Long thread like Structure||3: Hatches from egg or moth|
FAQs (Frequently Asked Questions)
Following are some of the significant themes discussed in Chapter 3 of the Class 7 NCERT Science textbook:
- Fibre to Fabric
- Different types of fibres
- Where can you get wool and silk?
- How do you process wool and satin into fibres?
The best way to utilise NCERT solutions is to first go through the chapter and attempt the problems on your own. Then compare your answers by cross-checking with the solutions prepared by Extramarks’ experts. That will give students a comprehensive understanding of both the chapter and how they should attempt questions related to the chapter in their exams.
Shearing is a method of removing animal hair using a machine similar to the one used by barbers.
Sericulture is the rearing of silkworms to produce silk.
Rearing is the practice of raising domestic animals such as sheep, goats, yaks, cows, and buffaloes for the extraction of milk and fur for economic uses.