Who proposed that opening and closing of stomata is connected with the change in pH of guard cells

Options

A. Lloyd
B. Von Mohl
C. Sayre/Scarth
D. Levitt

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks who proposed the connection between the opening and closing of stomata and the change in pH of guard cells.

2. **Identifying Key Concepts**:
- Stomata are small openings on the surfaces of leaves that allow for gas exchange.
- Guard cells are specialized cells that surround stomata and control their opening and closing.
- pH changes in guard cells can influence their turgor pressure, which in turn affects the stomatal aperture.

3. **Reviewing the Options**: The options provided are:
- Option 1: Lloyd
- Option 2: Von Moll
- Option 3: Scarth
- Option 4: Leavitt

4. **Analyzing Each Option**:
- **Lloyd**: He is known for his work on sugar and starch conversion in plants, not specifically related to pH and stomata.
- **Von Moll**: He focused on photosynthesis in guard cells, which does not directly relate to pH changes.
- **Scarth**: He proposed the theory that the opening and closing of stomata is related to the pH of guard cells.
- **Leavitt**: He discussed the conversion of starch into malic acid in guard cells under light conditions, but not specifically about pH.

5. **Conclusion**: Based on the analysis, the correct answer is **Option 3: Scarth**. He proposed the connection between the pH changes in guard cells and the opening and closing of stomata.

**Final Answer**: The correct option is **Option 3: Scarth**.

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