<u>N</u><u><em>atural selection acts on existing heritable variation</em></u>
Answer: Option C
<u>Explanation:</u>
Natural selection is a process that occurs in nature as a key to evolution. It also goes hand with the survival of the fittest. Nature always selects the best trait to survive or get accustomed to the surrounding by undergoing modifications.
It acts on the genotype of the existing generation and causes variation in the future generation. So the population over generations get to have acquired the variations in their body, structure so that it is adaptable to the surrounding.
<span>Two ATP </span><span> </span><span>During glycolysis, the overall gain of ATP per glucose molecule is 2. Although glycolysis produces 4 ATPs, it only uses 2 ATPs in the process!</span>
