Final answer:
T cells that recognize class I MHC molecules become cytotoxic T cells, while those that recognize class II MHC molecules become helper T cells.
Step-by-step explanation:
During T cell development in the thymus, those cells with receptors for class I major histocompatibility molecules develop into cytotoxic T cells (CD8+), whereas those with receptors for class II major histocompatibility molecules develop into helper T cells (CD4+). Cytotoxic T cells are responsible for directly killing infected cells by apoptosis and emit cytokines to amplify the immune response. On the other hand, helper T cells stimulate other immune cells, such as B cells or other T cells, by secreting cytokines or by direct stimulation, which aids in the immune response against pathogens