When a plant is rapidly transpiring it shows

Options

A. Decreased in height
B. Decreased in stem diameter
C. Increased in stem diameter
D. Decreased in leaf area

Answer

**Step-by-Step Solution:**

1. **Understanding Transpiration**: Transpiration is the process by which water is lost from a plant through small openings called stomata, primarily located on the leaves. When a plant is rapidly transpiring, it indicates that there is a significant loss of water.

2. **Conditions for Rapid Transpiration**: Rapid transpiration typically occurs under conditions of high temperature and when stomatal pores are open. This leads to an increased rate of water loss.

3. **Consequences of Excessive Water Loss**: If a plant loses too much water, it risks drying out, which can ultimately lead to its death. Therefore, it is crucial for plants to have mechanisms to minimize water loss during rapid transpiration.

4. **Plant Responses to Minimize Water Loss**:
- **Decrease in Stem Diameter**: One of the strategies plants use to counteract rapid transpiration is to reduce the diameter of their stems. A thinner stem means less water is contained within it, which subsequently reduces the potential for water loss through transpiration.
- **Height Adjustment**: While one might think that decreasing height could help, this is not a viable option for plants as height is linked to growth hormones and overall plant structure.
- **Leaf Area Consideration**: Reducing leaf area might seem like a solution, but it does not effectively reduce water loss through stomata since the number of stomata remains unchanged.

5. **Conclusion**: The most effective way for a plant to minimize water loss during rapid transpiration is by decreasing the diameter of its stem. This helps in reducing the amount of water available for transpiration, thus conserving water.

**Final Answer**: When a plant is rapidly transpiring, it shows a decrease in stem diameter to minimize water loss.

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