Which of the following is not an autoimmune disease?

Some people who have suffered from a disease may not be affected again during their life time; such immunity is called

An 'antigen' is

Assertion : Interferons are effective against viruses.

Reason : Proteins which can be synthesized only by genetic engineering are effective against viruses.

When an organ is transplanted and is rejected by the body, the lymphocytes are produced by

Humans have acquired immune system that produces antibodies to neutralize pathogens. Still innate immune system is present at the time of birth because it