What molecule do biological systems use to couple endergonic to exergonic reactions? Explain how this process works

Which of the following is an oxidation-reduction reaction? (pictured below)

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

To determine if a particular plant is homozygous or heterozygous, you would have to test cross with a