The answer is D, photosynthesis and respiration.
—Evidence—
Oxygen is a byproduct of photosynthesis and, correspondingly, carbon dioxide the byproduct of respiration.
Oxygen gives our cells the ability to break down food in order to get the energy we need to survive. Although other animals may use different organs to breathe with, they all get oxygen into their bodies through respiration.
This can happen because you have recessive and dominant characteristics passed down. So you can get a totally different chromosome that doesn't come from your parents because your grandparents may have had it or great grand parents, the line keeps going .
<span>3,3',5,5'-Tetramethylbenzidine or TMB is a chromogenic substrate visualising reagent used in enzyme-linked immunosorbent assays (ELISA), it yields a blue color when oxidized, typically as a result of oxygen radicals produced by the hydrolysis of hydrogen peroxide by HRP, (thermofisher). The expected colorimetric result from the negative control in your assay will be no development of blue color</span>