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

Give an example of ‘melt in mouth’ vaccine and state the advantages of such vaccines.

The meiocyte of rice has 24 chromosomes. How many chromosomes are present in its endosperm?

What is EcoRI? How does EcoRI differ from an exonuclease?

Why is tobacco smoking associated with rise in blood pressure and emphysema (Oxygen deficiency in the body)? Explain.

Give one example of autosomal recessive disorder.

Name the hormonal composition of the oral contraceptive used by human females. Explain how does it act as a contraceptive.

Why is selection process after hybridisation very crucial in breeding programmes?

A young boy when brought a pet dog home, started to complain of watery eyes and running nose. The symptoms disappeared when the boy was kept away from the pet.

1. Name the type of antibody and the chemicals responsible for such a response in the boy.
2. Mention the name of any one drug that could be given to the boy for immediate relief from such a response.

Explain with example what is meant by positive control of gene regulation.

What are the disorders caused due to hyposecretion and hypersecretion of GH or STH?