Secondary Immune Responses Upon a Second Exposure to a Pathogen

Question

Secondary immune responses upon a second exposure to a pathogen are due to the activation of
A) memory cells.
B) macrophages.
C) stem cells.
D) B cells.
E) T cells.

Accepted Answer

Secondary immune responses are generated due to the activation of memory cells. Memory cells are long-lived cells that remain in the body after the initial exposure to a pathogen and are able to quickly mount a response upon subsequent exposures. They can differentiate into both B cells and T cells, which work together to mount a faster and more effective response to the pathogen. Macrophages and stem cells are involved in the immune response, but they do not directly contribute to secondary immune responses.