Oxygen evolved during photosynthesis in Chlorella comes from

Options

A. `CO_2`
B. `CH_2O`
C. `H_2O`
D. Both (1) & (2)

Answer

To solve the question regarding the source of oxygen evolved during photosynthesis in Chlorella, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Photosynthesis**: Photosynthesis is the process by which green plants, including aquatic plants like Chlorella, convert light energy into chemical energy, using carbon dioxide and water to produce glucose and oxygen.

2. **Identifying the Organism**: Chlorella is a type of green algae that primarily lives in aquatic environments. This characteristic is crucial in understanding its photosynthetic process.

3. **Role of Water**: In photosynthesis, water (H2O) is split into oxygen (O2), protons (H+), and electrons. This process is known as photolysis and occurs in the thylakoid membranes of chloroplasts during the light-dependent reactions.

4. **Source of Oxygen**: The oxygen that is released as a byproduct of photosynthesis in Chlorella comes specifically from the splitting of water molecules. Therefore, the primary source of oxygen evolved during photosynthesis in Chlorella is water.

5. **Conclusion**: Based on the understanding of the photosynthetic process, the correct answer to the question is that the oxygen evolved during photosynthesis in Chlorella comes from water.

### Final Answer:
The oxygen evolved during photosynthesis in Chlorella comes from water.

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