Science (English Medium) Class 12 - CBSE Important Questions for Biology

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

How do normal cells get transformed into cancerous neoplastic cells? Elaborate giving three examples of inducing agent.

During a field trip, one of your friend in the group suddenly became unwell, she started sneezing and had trouble in breathing. Name and explain the term associated with such sudden responses. What would the doctor recommend for relief?

Many people experience allergic symptoms of sneezing or wheezing on exposure to certain substances in the environment. Give two examples of such substances. Which type of antibodies are produced by the body in response to these substances? Mention the role of mast cells in this kind of allergic response.

Name any two techniques used to detect the cancer of internal organs and write about any one of them.

Immunotherapy these days is one of the most efficient ways of treatment of cancer. The therapy involved activates the immune system and destroys the tumour.

1. Write an example of one such biological response modifier used in immunotherapy.
2. Why do patients need such substances if immune system is already working in body?
3. State what is 'Contact inhibition'.

A patient was advised to have a kidney transplant. To suppress the immune reaction, the doctor would administer him ______.

Explain the role of Primary and Secondary Lymphoid organs with the help of suitable examples.

Suggest four important steps to produce a disease resistant plant through conventional plant breeding technology.

Name a genus of baculovirus.

How do organic farmers control pests?

Name and explain the type of interaction that exists in mycorrhizae and between cattle egret and cattle.

Explain the different steps involved during primary treatment phase of sewage.

Explain the process of secondary treatment given to the primary effluent up to the point it shows significant change in the level of biological oxygen demand (BOD) it.

Why are the fruit juices bought from market clearer as compared to those made at home?