The development of a quick immune response in a person infected with deadly microbes by administering preformed antibodies is known as:

Which of the following cells act as phagocytes?

Which cells are responsible for acquired immunity?

In the figure,the structure of an antibody molecule is shown. Name the parts $A$,$B$,and $C$.

After maturation,in primary lymphoid organs,the lymphocytes migrate for interaction with antigens to secondary lymphoid organs like:
$A.$ thymus $B.$ bone marrow $C.$ spleen $D.$ lymph nodes $E.$ Peyer's patches
Choose the correct answer from the options given below:

Lymph nodes form: