Question

In the figure, the arrow at time (c) indicates?

1) exposure to a new antigen
2) the T-cell response
3) the time of exposure to the same antigen as at time (a)
4) the secondary response
5) the primary response

Answer 1

The arrow at time (c) indicates the time of exposure to the same antigen as at time (a), triggering a secondary immune response that is more rapid and robust due to memory cells.

Step-by-step explanation:

In the context of the adaptive immune response, the arrow at time (c) in Figure 21.24 most likely indicates the time of exposure to the same antigen as at time (a), which will result in a secondary response. This secondary immune response is characterized by a more rapid and robust response compared to the primary immune response, due to the presence of memory cells that were generated during the first exposure (time a). These memory cells are primed to recognize the antigen and rapidly mount an effective immune response, which results in the production of a larger number of effector T cells and antibodies in the case of B cells, thus preventing symptoms and quickly controlling the infection.