Which of the following does not affect light phase

Options

A. chlorophyll
B. Water
C. Cytochrome
D. Temperature.

Answer

To determine which of the following does not affect the light phase of photosynthesis, we need to analyze the options provided: chlorophyll, water, cytochrome, and temperature.

### Step-by-Step Solution:

1. **Identify the Components of the Light Phase**:
- The light phase of photosynthesis, also known as the light-dependent reactions, primarily involves chlorophyll, water, and certain proteins like cytochrome. These components are essential for capturing light energy and converting it into chemical energy.

2. **Evaluate Each Option**:
- **Chlorophyll**: This pigment is crucial for absorbing light energy. Without chlorophyll, the light phase cannot occur.
- **Water**: Water is a substrate in the light reactions, where it is split to release oxygen and provide electrons. Therefore, it directly affects the light phase.
- **Cytochrome**: This is a protein that plays a role in the electron transport chain during the light reactions. Its presence is necessary for the proper functioning of the light phase.
- **Temperature**: While temperature can influence the rate of photosynthesis, the light phase itself is not directly affected by temperature. The light reactions can occur over a wide range of temperatures, although extreme temperatures may eventually impact the overall process.

3. **Conclusion**:
- Based on the analysis, the component that does not affect the light phase of photosynthesis is **temperature**. The light phase can proceed without being significantly influenced by temperature variations.

### Final Answer:
**Temperature** does not affect the light phase of photosynthesis.

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