Answer:
The correct sequence is 2,3 and finally 1.
Explanation:
Proper order of the given passage is:
- From scientific evidence, the early atmosphere about 3.5-3.8 billion years ago was the mixture of gases CO2, CO, N2, H2, NH3, CH4.
- Organisms performing photosynthesis(aerobes) released free oxygen as waste product. This oxygen was poisonous to the anaerobes and anaerobes declined.
- As the oxygen in the air increased, aerobes became dominated and anaerobes were forced to live in the dark.
