Which one of the following generally acts as an antagonist to gibberellins

Options

A. ABA
B. IAA
C. Zeatin
D. Ethylene

Answer

To solve the question "Which one of the following generally acts as an antagonist to gibberellins?" we can follow these steps:

### Step-by-Step Solution:

1. **Understand Gibberellins**:
- Gibberellins are plant hormones that promote growth, particularly in processes like cell elongation and seed germination. They are known to increase plant height and facilitate bolting.

2. **Identify the Options**:
- The options given are:
- A) Abscisic Acid (ABA)
- B) Indole Acetic Acid (IAA)
- C) Zeatin
- D) Ethylene

3. **Analyze Each Option**:
- **A) Abscisic Acid (ABA)**:
- ABA is known as a plant growth inhibitor. It generally inhibits seed germination, which is the opposite effect of gibberellins that promote germination. Therefore, ABA acts as an antagonist to gibberellins.
- **B) Indole Acetic Acid (IAA)**:
- IAA is an auxin that promotes various growth processes but does not have an antagonistic effect on gibberellins.
- **C) Zeatin**:
- Zeatin is a cytokinin that promotes cell division and does not act antagonistically to gibberellins.
- **D) Ethylene**:
- Ethylene is involved in fruit ripening and does not oppose the actions of gibberellins.

4. **Conclusion**:
- Based on the analysis, the only hormone that acts antagonistically to gibberellins is **Abscisic Acid (ABA)**.

### Final Answer:
The correct answer is **A) Abscisic Acid (ABA)**.

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