Which of these describes a quantitative observation?
oa) an observation of the phenomenon itself
ob) an observation of the relative size of something
oc) an observation of an effect the phenomenon has
od) 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.