CAM plants open their stomata during night only because they tend to

Options

A. Pormote the rate of light reaction
B. Promote rate of dark reaction
C. Minimise rate of transpiration
D. Maximise rate of transpiration.

Answer

**Step-by-Step Solution:**

1. **Understanding CAM Plants**: CAM (Crassulacean Acid Metabolism) plants are a type of plant that have adapted to arid environments. They open their stomata at night instead of during the day.

2. **Stomata Function**: Stomata are small openings on the surfaces of leaves that allow for gas exchange. They typically open to take in carbon dioxide (CO2) for photosynthesis and release oxygen (O2).

3. **Reason for Night Opening**: CAM plants open their stomata at night to minimize water loss. In hot and dry conditions, opening stomata during the day would lead to excessive transpiration (loss of water vapor).

4. **Carbon Fixation**: During the night, CAM plants fix CO2 into organic acids (like malate) which are stored until daytime. During the day, when the stomata are closed, these acids are converted back to CO2 for use in the Calvin cycle, allowing photosynthesis to occur without losing water.

5. **Conclusion**: The primary reason CAM plants open their stomata at night is to minimize the rate of transpiration, thus conserving water.

**Final Answer**: CAM plants open their stomata during night only because they tend to minimize the rate of transpiration.

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