Which of the following scientist showed that it is only the green part of the plants that would release oxygen?

Options

A. Joseph Priestley
B. Jan Ingenhousz
C. T. W. Engelmann
D. C. van Niel

Explanation

To answer the question of which scientist demonstrated that it is only the green parts of plants that release oxygen, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Key Scientists**: The question refers to scientists who contributed to the understanding of oxygen release in plants. The two key figures mentioned are Joseph Priestley and Jan Ingenhousz.

2. **Understand Priestley's Contribution**: Joseph Priestley was the first scientist to discover that plants release oxygen. He conducted experiments that indicated that plants could restore air that had been "injured" by burning candles or respiration.

3. **Examine Ingenhousz's Findings**: Jan Ingenhousz built upon Priestley's work. In 1779, he conducted experiments that showed that oxygen production in plants occurs only in the presence of light and specifically in the green parts of the plants.

4. **Highlight the Role of Light and Green Parts**: Ingenhousz found that when he placed aquatic plants in light, they produced oxygen bubbles, but this did not happen in the dark. This indicated that the green parts of the plants, which contain chlorophyll, are essential for photosynthesis and oxygen release.

5. **Conclude the Correct Answer**: Based on Ingenhousz's experiments, it is clear that he is the scientist who demonstrated that only the green parts of plants release oxygen when exposed to light.

### Final Answer:
The correct answer is **Jan Ingenhousz**.

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