Who domonstrated that photosynthesis is essentially a light-dependent reaction?

Options

A. Cornelius van Niel
B. Julius van Sach
C. Ingenhousz
D. T.W. Engelmass

Answer

To solve the question of who demonstrated that photosynthesis is essentially a light-dependent reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Photosynthesis**:
- Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose, using carbon dioxide and water.

2. **Identify the Key Aspect of Photosynthesis**:
- The question specifically asks about the light-dependent reactions, which are the initial phase of photosynthesis where light energy is captured and converted into chemical energy (ATP and NADPH).

3. **Review the Options Provided**:
- Option A: Cornelius Van Neel
- Option B: Julius Van Sack
- Option C: Engelhaus
- Option D: T. W. Engelmass

4. **Recall Historical Contributions**:
- Cornelius Van Neel is known for his work on photosynthesis, particularly in demonstrating that photosynthesis involves light-dependent reactions.

5. **Select the Correct Answer**:
- Based on the information, the correct answer is **Option A: Cornelius Van Neel**. He was the scientist who demonstrated that photosynthesis is essentially a light-dependent reaction.

### Final Answer:
The scientist who demonstrated that photosynthesis is essentially a light-dependent reaction is **Cornelius Van Neel** (Option A).

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