What accounts for genetic material from each of an organism’s parents being present in sperm and egg 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 .

The smallest biological units that can evolve are

Name 3 injuries and two diseases that affect the skeletal system.