Why does the phylogenetic tree tell you about the evolutionary relationships of animals?
a. animals are unrelated to one another.
b. animals have many different ancestors.
c. animals belong to serval different kingdoms.
d. animals descended from one ancestor.

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.