Which describes one of oxygen's roles in Earth's atmosphere

Oxygen: Oxygen is one of the essential gases for the living beings to survive. The plants produce oxygen as a result of photosynthesis and it has a wide range of role in Earth's atmosphere. Roles: Allows fuels to burn - Oxygen is the reason for combustion. Hope this helps :))

Explanation:

the calvin cycle has three stages. in stage 1, the enzyme rubisco incorporates carbon dioxide into an organic molecule. in stage 2, the organic molecule is reduced. in stage 3, rubp, the molecule that starts the cycle, is regenerated so that the cycle can continue