Two species of flies, Drosophila melanogaster and Drosophila simulans, can mate. They usually do not mate, however, even if they are kept together in a laboratory. Males court the females of both species, but the females prefer to mate with males of their own species. Which isolating mechanism does this describe?

1.behavioral
2.temporal
3.artificial
4.anatomical

There are few cells in the body that do not undergo mitosis: most somatic cells divide regularly, some more than others. take for example the cells that line the digestive tract. these cells must be frequently replaced because they are constantly eroded by the movement of food through the tract. what mechanism(s) is/are in place to ensure that these cells are exact copies of the mother cell