What are antigens composed of?

The immune response provided by the body against pathogens with the help of $B$-lymphocytes is which type of immunity?

Match the antibodies in List-$I$ with their respective functions in List-$II$.

List-$I$	List-$II$
$(a)$ $IgG$	$(i)$ Protection of body surfaces
$(b)$ $IgA$	$(ii)$ Regulation of allergic reactions
$(c)$ $IgM$	$(iii)$ Activates $B$-cells
$(d)$ $IgD$	$(iv)$ Protection of body fluids
$(e)$ $IgE$	$(v)$ Protection of blood circulation

What is the full form of $MALT$?

Which of the following is $NOT$ associated with lymphoid organs?

Assertion : Organ transplantation patients are given immunosuppressive drugs.
Reason : Transplanted tissue has antigens which stimulate the specific immune response of the recipient.