Your answer is a: how DNA is formed.
monosaccharides. Such as glucose or fructose
Oxygen and carbon dioxide is exchanged by the millions of alveoli in the lungs and the capillaries that envelop them. we inhale oxygen (which is then exchanged with carbon dioxide in the lungs) and then we exhale the carbon dioxide. although, the air that we breathe usually consists more nitrogen than oxygen.
Higher genetic diversity allowing Dawrin's theory of evolution to have more effect and the species can evolve ore/better