Answer:
Antibodies are the Immunoglobulins that are formed to act against foreign cells or substances. Antibodies are produced by B- lymphocytes against the antigens that come from outside the body.
The encounter of antigen with B- cells actives the B-cells which then converts into memory B-cell and plasma B-cell. Memory B-cell allows the recognition of antigen after its second exposure in the body and initiates rapid response by activating B and T cells.
Plasma B-cells produce lots of antibodies which have antigen-binding site and binds to the epitope of the antigen and helps in killing the antigen by making the antigen recognized by phagocytic cells. The phagocytic cells engulf the antigen-antibody complex and destroys the pathogen.