A well-watered herbaceous plant exhibits a decrease in the rate of transpiration in intense light, this is due to

Options

A. Photo-oxidation of chlorophyll
B. Loss of water from the soil
C. Loss of water from the soil
D. Partial closure of stomata

Explanation

To solve the question regarding why a well-watered herbaceous plant exhibits a decrease in the rate of transpiration in intense light, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Transpiration**: Transpiration is the process by which water vapor is lost from the plant, primarily through small openings called stomata. It is influenced by various environmental factors, including light intensity.

2. **Effect of Intense Light**: In intense light, the temperature of the environment tends to increase. This generally leads to an increase in the rate of transpiration because higher temperatures can increase the rate of evaporation of water from the plant's surfaces.

3. **Water Loss Consideration**: As transpiration increases, the water levels within the plant can decrease. This can lead to a potential water deficit, which can be detrimental to the plant's health.

4. **Plant's Response to Water Loss**: To counteract the loss of water and prevent dehydration, the plant has mechanisms to regulate transpiration. One of the primary responses is the partial closure of stomata.

5. **Partial Closure of Stomata**: By partially closing the stomata, the plant can reduce the rate of transpiration without completely stopping gas exchange. This allows the plant to maintain adequate water levels while still facilitating some level of photosynthesis.

6. **Conclusion**: Therefore, the decrease in the rate of transpiration in intense light in a well-watered herbaceous plant is primarily due to the partial closure of stomata.

### Final Answer:
The decrease in the rate of transpiration in intense light in a well-watered herbaceous plant is due to the **partial closure of stomata**.

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