In CAM - plants , carbon dioxide required for photosysnthesis enters the plant body during

Options

A. Day time through the lenticels
B. Night through the stomata, which are kept open
C. Day time when the stomata are open
D. Night when the hydathodes are open

Answer

**Step-by-Step Solution:**

1. **Understanding CAM Plants**:
- CAM stands for Crassulacean Acid Metabolism. These plants have adapted to arid conditions by altering their photosynthesis process.
- Example: Pineapple is a well-known CAM plant.

2. **CO2 Uptake Timing**:
- In CAM plants, carbon dioxide (CO2) is absorbed at night. This is a crucial adaptation to minimize water loss during the hotter daytime.

3. **Mechanism of CO2 Fixation**:
- At night, when the stomata (tiny openings on leaves) are open, CO2 enters the plant and is converted into organic acids (like malate) for storage.
- During the day, when the stomata are closed to conserve water, these organic acids release CO2 for the Calvin cycle, allowing photosynthesis to occur.

4. **Identifying the Correct Option**:
- The question asks when CO2 enters the plant body in CAM plants. The correct answer is during the night when the stomata are open.
- Therefore, the correct option is **B**: "night to the stomata which are kept open."

5. **Conclusion**:
- CAM plants are uniquely adapted to their environments, allowing them to photosynthesize efficiently while minimizing water loss.

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