What are the advantages and the disadvantages of using a resource person in teaching a first aid lesson

Which of the following correctly list the first appearance of organism in the fossil record from earliest to most recent

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.

Some substances but not other can cross the (blank) membrane of a cell