Essentiality of light in photosynthesis can be demonstrated by

Options

A. Moll's half leaf experiment
B. Ganong screen
C. Inverted funnel experiment
D. KOH solution

Answer

To demonstrate the essentiality of light in photosynthesis, we can conduct an experiment known as Ganon's screen experiment. Here’s a step-by-step breakdown of how this experiment works:

### Step-by-Step Solution:

1. **Understanding the Objective**: The goal of the experiment is to show that light is essential for photosynthesis. Without light, plants cannot perform this process.

2. **Setting Up the Experiment**:
- Obtain a healthy green leaf from a plant that is known to perform photosynthesis.
- Use Ganon's light screen, which is a device that can selectively block light from reaching a part of the leaf.

3. **Applying the Light Screen**:
- Place the Ganon's screen over a specific portion of the leaf. This screen will prevent light from reaching that part of the leaf while allowing the rest of the leaf to be exposed to light.

4. **Observation Period**:
- Leave the setup in a well-lit environment for a certain period, allowing the exposed part of the leaf to undergo photosynthesis while the covered part does not receive any light.

5. **Testing for Photosynthesis**:
- After the observation period, test both the covered and uncovered parts of the leaf for the presence of starch (a product of photosynthesis). This can be done using iodine solution, which turns blue-black in the presence of starch.

6. **Analyzing Results**:
- The uncovered part of the leaf will show a blue-black coloration, indicating the presence of starch, while the covered part will remain brown or unchanged, indicating that no starch was produced there.

7. **Conclusion**:
- The results demonstrate that the part of the leaf that was exposed to light underwent photosynthesis and produced starch, while the part that was covered did not. This clearly shows that light is essential for the process of photosynthesis.