In which stages of photosynthesis are $C_{2}O$ and $O_2$ involved in $\mathrm{ATP}$ production?

• A. $C_{2}O$ is involved in the light-dependent reactions, and $O_2$ is a byproduct of the Calvin cycle.
• B. Both $C_{2}O$ and $O_2$ are involved in the light-dependent reactions.
• C. Both $C_{2}O$ and $O_2$ are involved in the Calvin cycle.
• D. $C_{2}O$ is involved in the Calvin cycle, and $O_2$ is a byproduct of the light-dependent reactions.

Answer: (D)

Verified step by step guidance

1. Understand the two main stages of photosynthesis: the light-dependent reactions and the Calvin cycle (light-independent reactions).
2. Recognize that the light-dependent reactions occur in the thylakoid membranes of chloroplasts, where sunlight is used to split water molecules, releasing oxygen as a byproduct.
3. Identify that the Calvin cycle takes place in the stroma of chloroplasts, where carbon dioxide is fixed into organic molecules using ATP and NADPH produced in the light-dependent reactions.
4. Note that oxygen is not directly involved in ATP production but is released during the light-dependent reactions as water is split.
5. Understand that carbon dioxide is utilized in the Calvin cycle to produce glucose, using the ATP generated in the light-dependent reactions.