How do veins return blood to the
heart?
A. using simple and
facilitated diffusion
B. using osmosis and
simple diffusion
C. using capillaries and
arteries
D. using valves and muscle
contractions

What type of genetic drift would be simulated if all the beans that were not selected died out?

How are the testes and ovaries similar? a. both produce sex cells. b. both connect internal reproductive organs to the exterior. c. both transport sex cells from their site of production. d. both store mature sex cells.

The image shows the evolution of a species of fish. a few fish from a population developed different social behaviors and evolved into different species. two fish according to the image, the fish underwent . the new species of fish had mating seasons that were different from that of the original fish. because of the differences in mating seasons, the fish underwent reproductive isolation. this mode of isolation would be .