Describe how oil and natural gas compare in terms of predicted supply and carbon dioxide emissions.

The diagram shows the layers of earth. convection currents in which region influence the movement of tectonic plates

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.

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?