Final answer:
The secondary response of antibodies to an antigen occurs more rapidly and in greater numbers due to memory B cells, which upon re-exposure differentiate into plasma cells that produce large amounts of high-affinity antibodies quickly.
Step-by-step explanation:
The secondary response of antibodies (response to a second exposure of an antigen) occurs more rapidly and in greater numbers because of memory B cells. During the primary immune response, B cells differentiate into plasma cells that produce antibodies and memory B cells that will respond to subsequent exposures. The secondary antibody response initiated by memory B cells develops more quickly, produces higher and more sustained levels of antibody with higher affinity for the specific antigen. Since memory B cells have already been exposed to the antigen, upon re-exposure they differentiate into plasma cells that secrete antibodies in much greater amounts and for a longer period of time compared to the primary response. This rapid and enhanced response may prevent the infection from establishing itself, often without the individual realizing they were exposed to the pathogen again.