Which statement about the atmosphere and life on Earth is correct?
A)Life on Earth arose once oxygen was present.
B)Life on Earth arose once temperatures of gases warmed.
C)Life on Earth arose before oxygen was present.
D)Life on Earth arose once the products of photosynthesis such as oxygen were present.

Question

Quizplus · Accepted Answer

Life on Earth is believed to have arisen before oxygen was present in the atmosphere. Early life forms were anaerobic, meaning they did not require oxygen for their metabolism. Oxygen began to accumulate in the Earth's atmosphere as a result of photosynthesis by these early life forms, particularly cyanobacteria, in a process known as the Great Oxygenation Event. This accumulation of oxygen drastically changed the Earth's atmosphere and allowed for the evolution of aerobic life forms that use oxygen to produce energy.

Which Statement About the Atmosphere and Life on Earth Is