Order the following metabolic innovations to reflect the most likely order in which they evolved during biological evolution. Your answer would be a four-letter string composed of letters A to D only, e.g. BDCA.
(A) Using light energy to generate reducing power
(B) Splitting of water molecules (an electron source)
(C) Fermentation of organic material
(D) Reduction of molecular oxygen (a terminal electron acceptor)

Question

Order the following metabolic innovations to reflect the most likely order in which they evolved during biological evolution. Your answer would be a four-letter string composed of letters A to D only, e.g. BDCA.
(A)	Using light energy to generate reducing power
(B)	Splitting of water molecules (an electron source)
(C)	Fermentation of organic material
(D)	Reduction of molecular oxygen (a terminal electron acceptor)

Quizplus · Accepted Answer

Aerobic metabolism evolved after molecular oxygen became abundant due to the activity of ancient cyanobacteria. Fermentation is thought to have arisen before the harnessing of light energy to produce reducing power.

Order the Following Metabolic Innovations to Reflect the Most Likely