Q1. Activation of T cells requires that antigens be presented from antigen-presenting cells, not simply by exposure to the antigen in solution. What biological rationale may underlie this requirement – consider both from the perspective of how this can aid in generation of a cytotoxic T cell response, and how it could aid in avoiding undesirable T cell responses.

Q2. What are Nuc, Flag, ER, Mito, Chlora, Golgi, Ves and Lys short for? What does each of these organelles do in the cell?