Stomata close at relative humidity of

Options

A. 60%-70%
B. 50%-60%
C. 50%-70%
D. Less than 50%

Answer

**Step-by-Step Solution:**

1. **Understanding Stomata Function**: Stomata are small openings on the surface of leaves that facilitate gas exchange and transpiration in plants. Their opening and closing are crucial for maintaining water balance and gas exchange.

2. **Factors Affecting Stomatal Opening and Closing**: The opening and closing of stomata are influenced by several factors, including light intensity, carbon dioxide concentration, and relative humidity.

3. **Role of Relative Humidity**: Relative humidity is a measure of the amount of moisture in the air compared to the maximum amount of moisture the air can hold at a given temperature. It plays a significant role in determining whether stomata open or close.

4. **High Relative Humidity**: When relative humidity is high (above 70%), it promotes the opening of stomata. In such conditions, plants can afford to lose water through transpiration without risking dehydration.

5. **Low Relative Humidity**: Conversely, when relative humidity is low (less than 50%), the environment is considered dry. In these conditions, stomata tend to close to minimize water loss and prevent dehydration of the plant.

6. **Conclusion**: Based on the understanding of how relative humidity affects stomatal behavior, we can conclude that stomata close at a relative humidity of less than 50 percent. Therefore, the correct answer to the question is "less than 50 percent."

**Final Answer**: Stomata close at relative humidity of **less than 50 percent**.

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