How many types of immunity are there?

The secretion of interferon is inhibited by . . . . . . .

Where is $MALT$ (Mucosa-Associated Lymphoid Tissue) located?

Which of the following are primary lymphoid organs?

Assertion: Artificially acquired passive immunity results when antibodies or lymphocytes produced outside the host are introduced into a host.
Reason: $A$ bone marrow transplant given to a patient with genetic immunodeficiency is an example of artificially acquired passive immunity.

Active immunity is obtained by