Precursor of cytokinin is

Options

A. A pyrimidine
B. A purine
C. Carotenoid
D. Methionine

Answer

To determine the precursor of cytokinin, we can follow these steps:

1. **Understanding Cytokinins**: Cytokinins are a class of plant hormones that promote cell division and growth. The name "cytokinin" derives from "cyto," meaning cell, and "kinin," meaning to divide.

2. **Identifying the Source**: The first cytokinin discovered was kinetin, which was derived from herring sperm DNA. This indicates that the precursor of cytokinin is related to nucleic acids.

3. **Analyzing Kinetin**: Kinetin is chemically classified as a derivative of adenine, which is a purine. This means that the structure of kinetin is closely related to adenine.

4. **Understanding Purines**: Purines are a type of nitrogenous base that include adenine and guanine. Since kinetin is derived from adenine, we can conclude that adenine is the precursor of cytokinin.

5. **Final Conclusion**: Therefore, the precursor of cytokinin is adenine, which is a purine.

**Final Answer**: The precursor of cytokinin is adenine (a purine).

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