It constitutes about $50$ percent of the lymphoid tissue in human body.
Spleen
Bone marrow
MALT
Thymus
Which is an example of active immunity ?
Which one of the following depresses brain activity and produces feelings of calmness, relaxation and drowsiness
Ergot, which is an important source of a drug is obtained from
‘Vaccination' was invented by
Which virus, for the first time, was synthesised in the form of non-living crystals