Why do biologists believe glycolysis evolved before the Krebs cycle and the electron transport chain?

Question

Quizplus · Accepted Answer

It is believed that glycolysis is an ancient metabolic pathway and evolutionary conserved in all living organisms, while the Krebs cycle and electron transport chain are more complex and only found in more advanced organisms. Therefore, it is likely that glycolysis evolved before the Krebs cycle and electron transport chain. Option A is incorrect because glycolysis occurs in the cytoplasm and not in mitochondria. Option B is incorrect because glycolysis is an anaerobic process that does not require oxygen. Option D is incorrect because while glycolysis is essential for energy production, it is not as efficient as the Krebs cycle and electron transport chain in generating ATP.

Why Do Biologists Believe Glycolysis Evolved Before the Krebs Cycle