Answer:
Water
Explanation:
Molecular oxygen is the terminal electron acceptor and serves to receive electrons from reduced NADH and FADH2 to reoxidize them. NADH and FADH2 are formed during glycolysis and Kreb's cycle. These reducing powers should be re-oxidized to enter in the first two steps of aerobic respiration again.
For the purpose, NADH, and FADH2 transfer their electrons to the molecular oxygen via electron transport chain. After accepting the electrons, molecular oxygen is oxidized into the water molecule. Therefore, radioactive oxygen isotope would appear in the form of a water molecule after completion of cellular respiration.
So if it's 20% adenine (A) then it's 20% (T)...because A always pairs with T. That adds up to 40%....60% therefore is G+C...so you'd have 30% Cytosine (C) and 30% Guanine (G).
I would go with b-genetic engineering (:
