Which of the following statements could be used to support the idea that anaerobic respiration existed prior to aerobic respiration in the history of our planet?
1. You have to do anaerobic respiration before your cells can begin to do aerobic respiration.
2. The early atmosphere was high in CO2 and low in O2 so until photosynthesis could produce large amounts of oxygen, organism had to use anaerobic respiration.
3. The early atmosphere was high in CO2 and low in O2 so until photosynthesis could produce large amounts of oxygen, organism had to use aerobic respiration.
4. The early atmosphere was high in O2 and low in CO2 so until photosynthesis could produce large amounts of carbon dioxide, organism had to use anaerobic respiration.