Oxygen in the Earth's atmosphere is derived from
A) volcanic outgassing.
B) photosynthesis.
C) animal respiration.
D) water from the oceans breaking down into hydrogen and oxygen during evaporation.

Question

Quizplus · Accepted Answer

Oxygen in the Earth's atmosphere is primarily derived from photosynthesis. During photosynthesis, plants and other photosynthetic organisms use energy from the sun to convert carbon dioxide and water into glucose and oxygen. This process releases oxygen into the atmosphere, which has accumulated over billions of years to create the oxygen-rich atmosphere we have today.

Oxygen in the Earth's Atmosphere Is Derived from