Red drop effect was studied by

Options

A. Van Niel
B. Blink
C. Emerson
D. Calvin

Answer

**Step-by-Step Solution:**

1. **Identify the Concept**: The question asks about the study of the "Red drop effect". This effect is related to photosynthesis and the efficiency of light absorption at different wavelengths.

2. **Recall the Researchers**: The options provided are Van Neel, Blank, Emerson, and Kelvin. We need to determine which of these researchers studied the Red drop effect.

3. **Research the Red Drop Effect**: The Red drop effect refers to a phenomenon observed in photosynthesis where there is a decrease in photochemical efficiency when light wavelengths exceed 680 nanometers.

4. **Identify the Correct Researcher**: The Red drop effect was specifically studied by **Emerson** in the year **1957**. This is why it is also known as the **Emerson effect**.

5. **Conclusion**: Therefore, the correct answer to the question is **Emerson**.

**Final Answer**: The Red drop effect was studied by **Emerson**.

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