Plant Growth and Mineral Nutrition — BIOLOGY STD 12 Science — Question

Draw a labelled diagram of T.S. of root nodule.

Describe the embryonic development of a zygote upto its implantation in humans.

A heavily bleeding and bruised road accident victim was brought to a nursing home. The doctor immediately gave him an injection to protect him against a deadly disease.

1. Write what did the doctor inject into the patient's body.
2. How do you think this injection would protect the patient against the disease?
3. Name the disease against which this injection was given and the kind of immunity it provides.

How does tongue detect the sensation of taste?

Give reasons : Glottis is guarded by a flap called epiglottis.

What is inbreeding depression and how is it caused in organisms? Write any two advantages of inbreeding.

1. Write the two limitations of traditional breeding technique that led to promotion of micro propagation.
2. Mention two advantages of micro propagation.
3. Give two examples where it is commercially adopted.

A woman has certain queries as listed below, before starting with contraceptive pills. Answer them.
What schedule should be followed for taking these pills?

Vaibhav, 12th class student watched the movie 'Vicky donor'. He was very curious to know the structure and details of sperm. He wondered, why the donation of sperm is considered a taboo irrespective of the fact that it helps childless couples to have children. He discussed this whole thing with his elder brother, who is a biology professor in a university. His brother smiled and explained all his queries.

1. Name the main parts of a sperm.
2. Which part of the human sperm is responsible for facilitating sperm motility? Explain.
3. What are the values shown by Vaibhav?

Comment on the essential features required for an ideal contraceptive.