A Second Exposure to an Antigen, Even Years After the First

Question

A second exposure to an antigen, even years after the first exposure, ________.
A) results in a much more rapid immune response
B) stimulates an immune response that requires about 2 weeks to be effective
C) stimulates complement production
D) stimulates passive immunity

Accepted Answer

A second exposure to an antigen triggers memory cells that recognize the antigen and respond more quickly than the first exposure, resulting in a more rapid immune response.