If the conditions required for substantial amounts of oxygen to build up in a planetary atmosphere are quite rare, then life on other worlds
A) will probably not be present
B) will progress much more rapidly because there would be less oxidation
C) will progress at a similar rate as that on the Earth, except that it will remain anaerobic
D) may still be common but may never be able to evolve past microscopic forms

Question

Quizplus · Accepted Answer

The rarity of conditions for substantial oxygen buildup in planetary atmospheres does not necessarily preclude the presence of life on other worlds. However, without significant levels of oxygen, the evolution of complex organisms may be hindered and life may remain at the microscopic level.

If the Conditions Required for Substantial Amounts of Oxygen to Build