First natural cytokinin was discovered by

Options

A. Skoog and Miller
B. Letham
C. Benson and Calvin
D. Thimann and Went.

Answer

**Step-by-Step Solution:**

1. **Understanding Cytokinins**: Cytokinins are a class of plant hormones that promote cell division (cytokinesis) in plant roots and shoots. They play a crucial role in various plant growth processes.

2. **Historical Context**: The question asks about the first natural cytokinin discovered. This requires knowledge of the history of plant hormone research.

3. **Identifying Key Figures**: The video mentions several names associated with the discovery of cytokinins: Skoug and Miller, Lethem, Benson and Kelvin, and Thiemann and Wendt.

4. **First Cytokinin Discovery**: According to the video, the first cytokinin was isolated from herring sperm in 1955 by Miller and his associates. This compound was named kinetin due to its role in promoting cytokinesis.

5. **Natural Cytokinin Discovery**: The first naturally occurring cytokinin was discovered later in 1961, also by Miller and his associates, this time from corn, and it was named zeatin.

6. **Final Answer**: Based on the information provided, the first natural cytokinin was discovered by Skoog and Miller, as Skoog was one of the associates working with Miller.

**Final Answer**: The first natural cytokinin was discovered by Skoog and Miller.

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