ISC (Science) ISC Class 12 - CISCE Important Questions

An antiviral protein released from infected and dying cells is ______.

Expand the following: SCID

Name the antibody which is most effective in allergies.

Give one significant difference between primary lymphoid organs and secondary lymphoid organs. Give one example of each.

A substance that stimulates the production of antibodies is called ______.

Briefly explain the role of the following in providing defence against infection in the human body:

B-cells

Briefly explain the role of the following in providing defence against infection in the human body:

T-cells

What are the vestigial organs?

Give any one example of a vestigial organ in human body.

If a person shows the production of interferons in his body, then he is suffering from ______.

Assertion: Lymphocytes originate and proliferate in primary lymphoid organs.

Reason: Spleen is a secondary lymphoid organ.

Observe the relation between the first two words and then fill in the fourth word.

Histamine: Mast cells :: Antibody: ______.

Expand DDT

Give reasons for the following:

Nitrogenous fertilizers are not applied in fields where leguminous crops grow.

Why are the spores of Bacillus thuringiensis used as bioinsecticide?

Give the biological name of the following:

The mould from which penicillin is obtained.

Give the biological name of the following:

The microbe used to control insect larvae growing on cotton.

Give the biological name of the following: 

The microbe used to produce Swiss cheese.

Give the biological name of the following:

The fungus that is being developed as a bio-control agent.

Give the biological name of the following:

A symbiotic nitrogen-fixing bacterium found in root nodules.