An operon encodes enzymes for making an essential amino acid and is regulated like the trp operon. which of the statements is true? a. the amino acid inactivates the repressor. b. the amino acid acts as a corepressor. c. inducible enzymes are produced. d. the repressor is active in the absence of the amino acid.

Imagine a self-reactive t cell that has not undergone clonal deletion in the thymus (that is to say, it has escaped central tolerance). if it encounters self antigen in the absence of an infection or inflammation, what will happen to this self-reactive t cell? (select two answers) (a) the t cell undergoes clonal expansion. (b) the t cell gains effector functions. (c) the t cell undergoes apoptosis. (d) the t cell becomes activated. (e) the t cell becomes anergic.