If a female frog has 13 chromosomes in
her eggs, how many chromosomes would
be present in a normal body cell?

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

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 is it called when lava when it erupts from the surface through volcanoes.