What does a dehydrogenase enzyme do?
a. creates a new bond by removing a carbon
b. inserts a water molecule into a bond to cut it
c. moves a chemical group to another site in the same molecule
d. oxidizes a substrate by removing a hydrogen molecule
e. uses atp to phosphorylate a substrate

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.