Evolution of oxygen during photosynthesis is a

Options

A. Light reaction
B. Dark reaction
C. Respiratory influence
D. Both light and dark reactions.

Explanation

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**: Photosynthesis is an anabolic process where green plants synthesize their own food using carbon dioxide and water in the presence of sunlight.

2. **Two Stages of Photosynthesis**: Photosynthesis occurs in two main stages: the light reactions and the dark reactions (Calvin cycle).

3. **Light Reactions**: The light reactions, also known as the photochemical phase, occur in the thylakoid membranes of the chloroplasts.

4. **Process of Light Reactions**: During the light reactions, sunlight is absorbed, leading to the splitting of water molecules (H2O).

5. **Water Splitting**: The splitting of water results in the formation of protons (H+), electrons, and oxygen (O2). The reaction can be summarized as:
\[ 2 H_2O \rightarrow 4 H^+ + O_2 + 4 e^- \]

6. **Oxygen Evolution**: The oxygen produced during this process is released into the atmosphere. This evolution of oxygen is a direct result of the splitting of water molecules during the light reactions.

7. **Conclusion**: Therefore, the evolution of oxygen during photosynthesis is specifically associated with the light reactions.

**Final Answer**: The evolution of oxygen during photosynthesis is a light reaction.

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