Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Biology

Explain the relationship between B-lymphocytes and T-lymphocytes developing an immune response.

It is said that vaccinations are a must for a healthy society. Justify.

How does the human body respond when vaccine is introduced into it?

Answer the following question:
The principle of vaccination is based on the property of the "memory" of the immune system. Taking one suitable example, justify the statement.

Answer the following question.
Differentiate between the roles of B-lymphocytes and T-lymphocytes in generating immune responses.

Mention one application for the following:

Cytokinin-barrier

State the functions of mast cells in allergy response.

State the function of interpherons.

State the role of the thymus as a lymphoid organ. Name the cells that are released from it and mention their function.

Mention one application of the following:
Passive immunization

Mention one application of the following:
Antihistamine

Mention one application of the following:
Colostrum

Water logging and soil salinity are some of the problems that have come in the wake of the Green Revolution. Discuss their causes and adverse effects to the environment.

A male honeybee has 16 chromosomes whereas its female has 32 chromosomes. Give one reason.

How many chromosomes do drones of honey bees possess?

State the difference between meiocyte and gamete with respect to chromosome number.

Briefly mention the contribution of T. H. Morgan in genetics.

Who had proposed the chromosomal theory of inheritance?

Name the type of cell division involved in the production of sperms by honey bees.

Answer the following question.
Compare in any three ways the chromosomal theory of inheritance as proposed by Sutton and Bovery with that of experimental results on pea plant presented by Mendel.