30. Why might eucaryotes have developed both NADH and NADPH?
Why go to the trouble of having both kinds of energy carriers?

31. What improvement in photosynthesis is found in green plants, but not in bacteria? What do green plants use as their source of reducing power? Is this substance normally a good reducing agent? What do green plants do to make it so?

32. Where did the free 0₂ come from that is found in the atmosphere of the Earth today?