One immature T cell has a weak affinity for the self MHC:self peptide complex, and one has a strong affinity for the complex. The one with weak affinity is positively selected; the one with strong affinity is induced to undergo apoptosis. What is the adaptive immune system trying to avoid?

MCQs on the immune system, including innate and adaptive immunity, the cells involved in each of process of the immune system and their role in the immune response, and how antibodies are used to confer immunity for future potential exposures.