Which of the following options shows a pair of antagonist Phytohormones with respect to the given feature ?

Options

A. Parthenocarpy : Auxin antagonist to Gibberellin
B. Abscission : Ethylene antagonist to Abscisic acid
C. Seed Germination : Gibberellin antagonist to Abscisic acid
D. Senescence : Gibberellin antagonist to Cytokinin

Answer

To solve the question regarding the pair of antagonist phytohormones, we will analyze each option provided and determine which pair represents antagonistic relationships based on their functions.

### Step-by-Step Solution:

1. **Understand the Concept of Antagonistic Phytohormones**:
- Antagonistic phytohormones are those that have opposing effects on plant processes. For instance, one hormone may promote a certain process while another inhibits it.

2. **Analyze Each Option**:
- **Option 1: Parthenocarpy - Auxin (Antagonist to Gibberellin)**:
- Parthenocarpy is the development of fruit without fertilization. Auxins and gibberellins both promote parthenocarpy. Therefore, they are not antagonistic. This option is incorrect.

- **Option 2: Abscission - Ethylene (Antagonist to Abscisic Acid)**:
- Abscission refers to the shedding of plant parts. Ethylene promotes abscission, while abscisic acid (ABA) can also promote it under certain conditions. Hence, they do not oppose each other consistently. This option is incorrect.

- **Option 3: Seed Germination - Gibberellin (Antagonist to Abscisic Acid)**:
- Gibberellins promote seed germination, while abscisic acid inhibits it by maintaining seed dormancy. This is a clear antagonistic relationship. This option is correct.

- **Option 4: Senescence - Gibberellin (Antagonist to Cytokinins)**:
- Gibberellins promote growth and delay senescence, while cytokinins also promote cell division and delay senescence. They do not have a clear antagonistic relationship. This option is incorrect.

3. **Conclusion**:
- The only correct pair of antagonist phytohormones based on the given features is **Gibberellin (promotes seed germination) and Abscisic Acid (maintains seed dormancy)**.

### Final Answer:
**The correct answer is Option 3: Seed Germination - Gibberellin (Antagonist to Abscisic Acid).**

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