The endomembrane system did not start developing until the atmosphere was
A) high oxygen, high carbon dioxide.
B) high hydrogen, low oxygen.
C) changing from low oxygen to high oxygen.
D) firmly in the age of aerobes.
E) all of these.

Question

Quizplus · Accepted Answer

The endomembrane system, which includes the endoplasmic reticulum, Golgi apparatus, and other membrane-bound organelles, likely evolved as a response to increasing oxygen levels in the atmosphere. The earliest cells did not have these structures, but as oxygen levels rose, cells needed to create specialized compartments for key cellular processes such as protein synthesis and transport. Therefore, the endomembrane system started developing when the atmosphere was changing from low oxygen to high oxygen.

The Endomembrane System Did Not Start Developing Until the Atmosphere