During day time , CAM plants procure carbon dioxide for photosynthesis from

Options

A. Pyruvic Acid
B. Oxaloacetic Acid
C. Oxalic Acid
D. Malic Acid

Answer

**Step-by-Step Solution:**

1. **Understanding CAM Photosynthesis**: CAM stands for Crassulacean Acid Metabolism, a photosynthetic pathway used by certain plants, particularly those in arid environments. This adaptation helps them minimize water loss.

2. **Stomatal Behavior**: In CAM plants, the stomata (tiny openings on leaves) remain closed during the day to prevent water loss through evapotranspiration. Instead, they open at night.

3. **Carbon Dioxide Uptake**: At night, when the stomata are open, CAM plants absorb carbon dioxide (CO2) from the atmosphere.

4. **Storage of Carbon Dioxide**: The absorbed CO2 is then converted into a four-carbon compound, primarily malic acid, which is stored in the vacuoles of the plant cells overnight.

5. **Daytime Photosynthesis**: During the day, when the stomata are closed, the stored malic acid is transported to the chloroplasts where it is converted back into CO2. This CO2 is then utilized in the process of photosynthesis.

6. **Conclusion**: Therefore, during the daytime, CAM plants procure carbon dioxide for photosynthesis primarily from malic acid.

**Final Answer**: During daytime, CAM plants procure carbon dioxide for photosynthesis from malic acid.

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