Which of the following is not included in triple response shown by ethylene ?

Options

A. Horizontal growth of seedling
B. Swelling of the Axis
C. Apical hook formation in dicot seedling
D. Promotion of male flower

Answer

To determine which option is not included in the triple response shown by ethylene, we need to first understand what the triple response is.

### Step-by-Step Solution:

1. **Definition of Ethylene**: Ethylene is a gaseous plant hormone that plays a crucial role in various plant processes, including fruit ripening and response to stress.

2. **Understanding the Triple Response**: The triple response of ethylene is a growth response observed in plants, particularly in seedlings, when they encounter obstacles or mechanical stress. The three components of this response are:
- **Inhibition of Root Elongation**: Ethylene inhibits the elongation of roots, causing them to grow shorter.
- **Enhanced Radial Swelling**: The hypocotyl (the stem of a germinating seed) swells, resulting in a thicker appearance.
- **Curved Apical Hook Formation**: The apical hook (the top part of the seedling) bends, allowing the seedling to navigate around obstacles.

3. **Identifying the Incorrect Option**: The question asks which of the following is not included in the triple response. The options typically include:
- Inhibition of root elongation
- Enhanced radial swelling
- Curved apical hook formation
- Promotion of male flowers (or some other unrelated option)

4. **Analyzing the Options**:
- The first three options are indeed part of the triple response.
- The option regarding the promotion of male flowers is not part of the triple response associated with ethylene.

5. **Conclusion**: Therefore, the correct answer is that the promotion of male flowers is not included in the triple response shown by ethylene.

### Final Answer:
The option that is not included in the triple response shown by ethylene is **Promotion of Male Flowers**.