What does the passing on of genes mean in reproduction?

What is a universal way that predation benefits the predator? predation increases mate availability. predation in defense of space. the predator gets the energy it needs to survive. the predator keeps parasites from hurting the species.

What are genotypes? what are phenotypes?

Body temperature is tightly regulated in mammals for example when external temperatures drop too much the body of a mammal responds by in order to its core temperature?