The characteristics like expansion, breaking dormancy, promoting germination and flowering are associated with

Options

A. Auxins
B. Gibberellins
C. Cytokinins
D. Ethylene.

Answer

To answer the question regarding the characteristics like expansion, breaking dormancy, promoting germination, and flowering, we will analyze the options provided and identify the plant growth regulator associated with these characteristics.

### Step-by-Step Solution:

1. **Identify the Characteristics**:
- The characteristics mentioned in the question are:
- Expansion (or stem elongation)
- Breaking dormancy
- Promoting germination
- Flowering

2. **Analyze Each Option**:
- **Auxins**:
- Primarily involved in apical dominance, cell elongation, and root growth. They do not significantly contribute to breaking dormancy or promoting germination and flowering.
- **Gibberellins**:
- Known for promoting stem elongation (expansion), breaking seed dormancy, enhancing germination, and inducing flowering. This aligns perfectly with all the characteristics listed in the question.
- **Cytokinins**:
- Primarily involved in cell division and shoot development. They do not play a major role in breaking dormancy or promoting germination and flowering.
- **Ethylene**:
- A gaseous hormone involved in fruit ripening and abscission (the dropping of leaves). It does not significantly contribute to stem elongation or breaking dormancy.

3. **Conclusion**:
- Based on the analysis, the plant growth regulator that is associated with all the characteristics mentioned (expansion, breaking dormancy, promoting germination, and flowering) is **Gibberellin**.

### Final Answer:
The correct answer is **Gibberellin**.

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