$MALT$ constitutes about _______ percent of the lymphoid tissue in human body.
$20$
$70$
$10$
$50$
What is Active immunity and Passive immunity ?
Antigen binding site in an antibody is found between
Given below the diagrammatic representation of lymph nodes
Label $A, B$ and $C$
Some people who have suffered from a disease may not be affected again during their life time; such immunity is called