Which one of the following hormones is chiefly concerned with cell division

Options

A. Auxin
B. Cytokinins
C. GA
D. 2,4-D

Answer

To answer the question "Which one of the following hormones is chiefly concerned with cell division?" we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Hormones**: The options given are auxin, cytokinins, GA (Gibberellic Acid), and 2,4-D (2,4-Dichlorophenoxyacetic acid).

2. **Understand the Role of Each Hormone**:
- **Auxin**: This hormone is primarily involved in apical dominance (the growth of the main stem over lateral buds) and parthenocarpy (development of fruit without fertilization). It is not chiefly responsible for cell division.
- **Cytokinins**: These hormones are known to promote cell division (cytokinesis) and also play a role in delaying leaf senescence (aging). They are specifically associated with stimulating the growth of new cells.
- **Gibberellic Acid (GA)**: This hormone is mainly responsible for promoting stem elongation and seed germination, not directly related to cell division.
- **2,4-D**: This is a synthetic auxin used primarily as a herbicide to control weeds and does not promote cell division.

3. **Determine the Correct Answer**: Based on the functions of the hormones, cytokinins are the hormones chiefly concerned with cell division.

4. **Conclusion**: Therefore, the correct answer to the question is **cytokinins**.

### Final Answer:
The hormone chiefly concerned with cell division is **cytokinins**.

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