If the dna molecule is so similar among all living things (the pairings are always the same and that there are only six components that make up dna), why is there so much diversity of life?

Which of the following is most likely the result of an organism having lipids in its body a) water cannot be absorbed through the surface of a leaf b)human eats fruits to get a quick source of energy c) a sheep sleeps for more hours in the winter d) a warm river is filled with fish and algae