Question Bank [2022] — BIOLOGY STD 12 Science — Question

How did an American Company, Eli Lilly use the knowledge of r-DNA technology to produce human insulin?

It is commonly observed that parents feel embarrassed to discuss freely with their adolescent children about sexuality and reproduction. The result of this parental inhibition is that the children go astray sometimes.

1. Explain the reasons that you feel are behind such embarrassment amongst some parents to freely discuss such issues with their growing children.
2. By taking one example of a local plant and animal, how would you help these parents to overcome such inhibitions about reproduction and sexuality?

Explain by taking three different examples, how certain organisms pull through the adverse conditions, when unable to migrate under stressful period.

A student on a school trip started sneezing and wheezing soon after reaching the hill station for no explained reasons. But, on return to the plains the symptoms disappeared. What is such a response called? How does the body produce it?

When did major mass extinction events occurred ?

(a) Name the hormone which is responsible for apical dominance.
(b) A farmer wants to remove broad-leaved weeds from the jawar plantation in his field. Suggest any plant hormone to remove such weeds.
(c) Mention any two applications of cytokinin.

Explain the chromosomal theory of inheritance.

A criminal blew himself up in a local market when was chased by cops. His face was beyond recognition. Suggest and describe a modern technique that can help establish his identity.

Why both the strands of DNA are not copied during transcription? Explain.

What is 'green revolution? Give any two examples each of the improved varieties of wheat and rice.