What are the different variations of genes called?

How are fungi more like an animal? they have a cell wall. they are heterotrophs that absorb their food. they produce seeds and have membrane-bound nucleus. they use sunlight for photosynthesis.

Scientists discover two populations of mice on either side of a major river. the two populations have almost identical genes but the mice from one side cannot breed with mice from the other. this is most likely because

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 .