What is the definition of Natural selection? In Environmental Science i just picked biology because it didnt have environmental science on here

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.

What type of reaction is photosynthesis

Veronica and her little sister, monique, are playing on a seesaw. if veronica weighs 75 pounds, and monique weighs 60 pounds, which statement is true?