Natural cytokinins are synthesised from

Options

A. Root apices
B. Developing shoot buds
C. Yound fruits
D. All of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Cytokinins**: Cytokinins are a class of plant hormones that play a crucial role in promoting cell division and growth in plants. They are essential for various plant developmental processes.

2. **Synthesis of Cytokinins**: Natural cytokinins are primarily synthesized in specific regions of the plant where rapid cell division occurs. These regions include:
- **Root Apices**: The tips of roots where new cells are formed and divided rapidly.
- **Developing Shoot Buds**: Areas where new shoots are forming, which also require rapid cell division.
- **Young Fruits**: As fruits develop, they undergo significant growth and cell division.

3. **Identifying the Source**: Given that cytokinins are synthesized in areas of active cell division, we can conclude that they are found in high concentrations in root apices, developing shoot buds, and young fruits.

4. **Conclusion**: Since all the mentioned areas (root apices, developing shoot buds, and young fruits) are sites of high cytokinin concentration, the correct answer to the question "Natural cytokinins are synthesized from" is **all of the above**.

**Final Answer**: All of the above.

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