Ravjot's mother always squeezes water from wet clothes in the spinner of a washing machine and then uses it to clean the floor:
$(a)$ Write the principle of the technique used in the above-mentioned process.
$(b)$ Write one more application of this technique.
$(c)$ What do you learn from Ravjot's mother?

Ria was studying about $DNA$ in her textbook,learning that $DNA$ molecules are responsible for constructing and organizing cells and are present as part of chromatin material in the nucleus to transfer hereditary information. Ria was confused about how she could know if she possesses all the hereditary information from her parents. Her mother explained that through their hair or cells,the $DNA$ of parents and a child can be matched.
$(a)$ What kind of qualities are shown by Ria's mother?
$(b)$ In which part of a cell is $DNA$ found? State its function.

Name any one method of incorporating desirable characters into a crop variety.

After combing his hair,Sameer kept the comb on the table where some pieces of paper were lying. He observed that the plastic comb attracted small pieces of paper. He was surprised to see this and asked his teacher about it. His teacher explained to Sameer that matter contains charged particles and that an electrically charged object can attract an uncharged object. Specifically,upon rubbing with dry hair,a comb acquires an electric charge,which then attracts the pieces of paper.
$(a)$ Give any other practical application of this.
$(b)$ What kind of qualities are shown by Sameer?

While making shikanjwi,Savy was aware of which substances to use,added sugar,salt,and water in different amounts,and mixed them thoroughly. She was amazed as it tasted the same throughout.
$(a)$ According to you,what qualities are possessed by Savy?
$(b)$ Why do you think shikanjwi tastes the same throughout?

How does catla differ from mrigal?