Which of these describes a quantitative observation?
a. an observation of the phenomenon itself
b. an observation of the relative size of something
c. an observation of an effect the phenomenon has
d. an observation that has a number associated with it

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.