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?
behavioral
temporal
artificial
anatomical

Mutations are changes in the dna

Atp is is our little "pocket" of energy. of course, if you have too little, then it means you have too little energy, and you'll pass out. the way to not have enough, is to have no energy sources (glucose, fats, proteins). you can't have too many atp molecules. cycles like the krebs cycle produce it, but if you have too much of any substrate (or too little for that matter), the cycle stops and atp is no longer made (it stops until substrate levels are such that the process can go on). in any case, this is unlikely since atp is constantly hydrolyzed and remade, even while you're asleep. you won't have too much. if you have zero, you are dead or dying.

The organism dies boomshakalaka