Two cytokinins are kinetin and Zeatin. What is the difference between the two?

Options

A. Kinetin is the active form of zeatin
B. Zeatin is the active form of kinetin
C. Zeatin is a synthetic cytokinin and kinetin is naturally occuring
D. Zeatin is a naturally occuring plant cytokinin, kinetin is not

Answer

### Step-by-Step Solution:

1. **Understanding Cytokinins**: Cytokinins are a class of plant hormones that play a crucial role in regulating plant growth and development. They are involved in various processes such as cell division, shoot formation, and delay of leaf senescence.

2. **Identifying the Two Cytokinins**: The two specific cytokinins mentioned in the question are kinetin and zeatin. Both are important for plant growth but differ in their origin and occurrence.

3. **Kinetin**: Kinetin is a synthetic cytokinin that was first discovered in the 1950s. It is not naturally found in plants but can be produced artificially. Kinetin is known for promoting cell division and has been used in various agricultural applications.

4. **Zeatin**: In contrast, zeatin is a naturally occurring cytokinin found in plants. It was first isolated from corn (Zea mays) and is involved in promoting cell division and growth in various plant tissues.

5. **Key Differences**:
- **Origin**: Kinetin is synthetic and not found in nature, while zeatin is a natural cytokinin present in plants.
- **Occurrence**: Kinetin is produced artificially, whereas zeatin is derived from natural sources, particularly from plant tissues.

6. **Conclusion**: The main difference between kinetin and zeatin lies in their origin—kinetin is synthetic and not naturally occurring, while zeatin is a natural cytokinin found in plants.