Glycolysis is likely to have evolved before the citric acid cycle and electron transport chain because
A) it has an older fossil record.
B) it is found in all living organisms.
C) it occurs inside the mitochondria.
D) the process is found in all primitive bacteria but lacking in many advanced organisms.
E) it produces more ATP than do the citric acid cycle and electron transport chain.

Question

Quizplus · Accepted Answer

Glycolysis is a universal metabolic pathway that is found in all living organisms, from the most primitive archaea and bacteria to eukaryotic cells. This suggests that glycolysis evolved prior to the development of more complex metabolic pathways such as the citric acid cycle and electron transport chain, which are found primarily in eukaryotes. The other options (A, C, D, and E) are incorrect. Glycolysis does not have a fossil record because it occurs at the cellular level, it occurs in the cytoplasm of the cell rather than inside mitochondria, and it is not necessarily found only in primitive bacteria. Additionally, glycolysis produces a relatively small amount of ATP compared to the citric acid cycle and electron transport chain.

Glycolysis Is Likely to Have Evolved Before the Citric Acid