Priya is in seventh grade and his elder brother is in college. There is a Saree draping competition at his brother's college and Priya went to the campus with her elder brother to witness the competition. While present at the event she noticed a girl wore a beautiful Saree. Priya was told by his brother's friend that the saree was made of silk and also informed her that it is too expensive and was once considered as a symbol of royalty.

Priya wanted to know more about this silk fabric, so she asked the following questions to his brother and his friends:

a) Name the source from which the silk is obtained.

b) Why was silk considered a symbol of royalty? 

c) In which country was silk developed first? When did silk-making reach India, and how?

 

Radha and Ram went to visit a sericulture farm with their parents. It is the cultivation of silkworms to produce silk. Silk is woven from the cocoons of silkworms. They were so excited by watching all the procedures.

But after some days they came across the news regarding animal activists. Animal activists oppose the present process of getting silk from the cocoon. Why do you think they are against it? 

Ishanvi was decorating the lit candles on her balcony on the occasion of Diwali. She carefully observed the wick of the candle and was pondering about the property of the material used to make it. She wondered if any other type of thread could be used instead of it.

She fondly took out her candle-making raw materials and made a beautiful lavender-scented candle with nylon thread centered in it as a wick. After sometimes of cooling, the wax set properly around the thread and it was all good to get lit.

She then lit the lavender candle with great contentment but immediately the thread burnt completely and the flame went off. The aroma of lavender turned into a plastic smell.

Help Ishanvi to understand the reason why nylon thread didn't work well as a wick.

Ritanshi, in English literature, read a rhyme about Mary Elizabeth Sawyer. Few lines from the famous poem are penned below:

"Mary had a little lamb;
Its fleece was white as snow;
And everywhere that Mary went,
The lamb was sure to go."

Nowadays, in textile industries, a variety of fabrics are woven and knitted. Some knitted fabrics are made from fibres which are obtained from the animals like sheep (lamb is a baby sheep), goats and yaks.

Ritanshi is an animal lover, and she got disheartened when she came to know that fleece is used to make fibres for human use. She was dejected upon the thought that these animals are killed to obtain the fleece. Help Ritanshi to learn what type of fibre is made from fleece. Do you really think that animals are killed for this purpose? If not, then make a note of, how the fleece is obtained from these animals.

Silk dates back thousands of years, and still to this day is highly regarded as one of the most valuable, luxurious fabrics. Even after all of those years, little has changed in the way silk is produced.

Sericulture is the term used to describe the process of gathering silkworms and harvesting the cocoon to collect the materials.

Female silk-moths lay around $300 – 500$ eggs at any one time. These eggs eventually hatch to form silkworms, which are incubated in a controlled environment until they hatch into larvae (caterpillars). This caterpillar produces a covering around it that hardens to form a cocoon. The cocoons are placed into boiling water to extract the thread.

Why are these cocoons placed in boiling water? What difference will it make if they will be placed in cold water?

The art of silk production is called sericulture. Sericulture provides gainful employment, economic development, and an improvement in the quality of life for people in rural areas, and thus plays an important role in anti-poverty programmes and prevents rural people from migrating to urban areas in search of work. Silk is a lustrous protein fibre that can be used as a textile fibre. Silk sarees, bedding, silk pillows, table cloths, wall hangings, and other items are made from it.

From the above comprehension, it is clear that silk has many uses. Now explain the process of rearing silkworms in sericulture.

In a classroom, a teacher was discussing the properties and applications of wool fibre. The teacher discussed how it is warm and comfortable to wear, wrinkle resistant, loses strength when wet, has a low lustre, is expensive, and is damaged by chlorine bleach. The teacher also explained how wool fibres are used to make woollen clothing, blankets, boots, saddle cloths, horse rugs, seat covers, and other items. During the class, one of the students questioned about the extraction of wool fibre from sheep. The teacher then said, "This is your homework."

Can you help the students in completing their homework by responding to the following question:
Write the various steps involved in getting wool fibre from sheep?

Rohan is a seventh grade student and his father is employed at a wool processing plant. One day, he saw that his father had a fever and that there was a little blister on his skin with surrounding oedema. With the assistance of his mother, he quickly took his father to a local hospital. The doctor diagnosed that the bacteria that cause this blood condition is typically found in wool.

Answer the following questions utilising the information above.

(a) Which processing unit does his father most likely belong to?

(b) What illness is Rohan's father suffering from?

Shree went shopping with her mum. Shree's mother noticed a saree showroom and went in to buy a saree. The mother liked a saree, but it was quite expensive, to which the salesman said that the saree was made of pure silk. But Shree's mother had doubt. In order to clarify her mother's doubt, the salesman performed a simple procedure to verify the purity of the fabric. 

Could you think of the simple procedure used to determine the fabric's purity?