Source of `CO_(2)` for photosynthesis during day in CAM plant is

Options

A. 3 DGA
B. Malic acid
C. OAA
D. Pyruvate

Answer

**Step-by-Step Solution:**

1. **Understanding CAM Plants:** CAM (Crassulacean Acid Metabolism) plants are a type of plant that adapt to arid conditions by opening their stomata at night to collect carbon dioxide (CO₂) and closing them during the day to minimize water loss.

2. **Nighttime CO₂ Uptake:** During the night, CAM plants take in CO₂ from the atmosphere. This CO₂ is then converted into organic acids, primarily malic acid, which is stored in the vacuoles of the plant cells.

3. **Daytime Photosynthesis:** During the day, when the stomata are closed, the stored malic acid is transported out of the vacuole and broken down to release the CO₂ that was previously captured at night.

4. **Calvin Cycle:** The released CO₂ is then used in the Calvin cycle to synthesize glucose and other carbohydrates, which are essential for the plant's energy and growth.

5. **Conclusion:** Therefore, the source of CO₂ for photosynthesis during the day in CAM plants is malic acid, which is derived from the CO₂ collected at night.

**Final Answer:** The source of CO₂ for photosynthesis during the day in CAM plants is **malic acid**.

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