Auxin does not increase

Options

A. rate of photosynthesis
B. rate of respiration
C. uptake of water by cells
D. plasticity of the cell wall

Explanation

To solve the question "Auxin does not increase," we need to analyze the four options provided and determine which one is not affected by auxin. Here’s a step-by-step breakdown:

### Step 1: Understand Auxin
Auxin is a type of phytohormone that plays a crucial role in plant growth and development. It influences various physiological processes in plants.

### Step 2: Analyze Each Option
1. **Rate of Photosynthesis**:
- Photosynthesis primarily depends on sunlight, carbon dioxide, and water. While auxin may influence growth and development, it does not directly increase the rate of photosynthesis since this process is reliant on light availability.

2. **Rate of Respiration**:
- Auxin can enhance the rate of respiration in plants. It is involved in various metabolic processes, thus increasing respiration rates.

3. **Uptake of Water by Cells**:
- Auxin influences the uptake of water by promoting cell elongation and affecting the permeability of cell membranes. Therefore, it does increase water uptake.

4. **Plasticity of the Cell Wall**:
- Auxin is known to affect the plasticity of the cell wall, allowing cells to elongate and grow. This means it does have an effect on this process.

### Step 3: Conclusion
From the analysis, the only option that does not increase due to auxin is the **rate of photosynthesis**. This is because photosynthesis is dependent on sunlight and not directly influenced by auxin levels.

### Final Answer
**Auxin does not increase the rate of photosynthesis.**

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