Moll's Half leaf experiment proves that

Options

A. light is essential for photosynthesis
B. `CO_2` is essential for photosynthesis
C. `O_2` is released during photosynthesis
D. Chlorophyll is essential for photosynthesis

Answer

**Step-by-Step Solution:**

1. **Understanding Moll's Half Leaf Experiment**: The experiment involves taking a leaf from a plant and inserting half of it into a sealed container (caged bottle) that contains potassium hydroxide (KOH) solution or pellets. This setup is crucial for testing the requirements of photosynthesis.

2. **Placement in Sunlight**: The plant with the modified leaf is then placed in sunlight for several hours. This is important as sunlight is a key factor in the process of photosynthesis.

3. **Testing for Starch**: After exposure to sunlight, the leaf is tested for the presence of starch using iodine solution. The presence of starch indicates that photosynthesis has occurred, as starch is a product of this process.

4. **Observation**: The part of the leaf that was inside the bottle containing KOH does not turn blue when tested with iodine. This indicates that there is no starch present in that part of the leaf.

5. **Conclusion**: The absence of starch suggests that photosynthesis did not occur in the part of the leaf that was in the KOH solution. The reason for this is that KOH absorbs carbon dioxide (CO2) from the air. Since the bottle was sealed, no CO2 was available for the leaf to use in photosynthesis.

6. **Final Statement**: Therefore, the experiment demonstrates that carbon dioxide is essential for photosynthesis. Without CO2, photosynthesis cannot take place, leading to no starch synthesis.

**Correct Answer**: Carbon dioxide is essential for photosynthesis.

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