Answer:
Natural selection occurs when some of those traits help some individuals survive and reproduce more than others. That causes their genes to become more common in the population over time, and it's the way species evolve to adapt to changes in their environment.
Explanation:
hope this helps =)
The answer is mitochondria
I think that the plains, because the temp. is the same all around, cuz its flat... the mountains get cold at the top
A,B,C,D I'm pretty sure, but check with others who answer the question too.