If you suspect major deficiency of antibodies in a person, to which of the following would you look for confirmatory evidence ?
Thymus is the site for the development and maturation of
The toxic substances produced by the foreign bodies are known as
Assertion : Interferons are effective against viruses.
Reason : Proteins which can be synthesized only by genetic engineering are effective against viruses.
What is the basic principle of vaccination ? How do vaccines prevent microbial infections ? Name the organism from which hepatitis $B$ Vaccine is produced.