Science (English Medium) Class 12 - CBSE Important Questions

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.

Name a genus of baculovirus.

How do organic farmers control pests?

Explain enzyme – replacement therapy to treat adenosine deaminase deficiency. Mention two disadvantages of this procedure.

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

Why do children cured by enzyme-replacement therapy adenosine deaminase deficiency need periodic treatment?

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.

Write the function of adenosine deaminase enzyme.

Expand the Given and mention one application of each:

PCR

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

Name the bioactive molecules produced by Trichoderma polysporum and Monascus purpureus.

Name the source of streptokinase. How does this bioreactor molecule function in our body?

How do mycorrhizae act as biofertilizers? Explain.

Suggest any two possible treatments that can be given to a patient exhibiting adenosine deaminase deficiency.