Which of the following phytohormones replaces female flowers with female flowers on monoecious plants of cucurbits ?

Options

A. IAA
B. Cytokinins
C. GA's
D. ABA

Answer

To solve the question regarding which phytohormone replaces female flowers with male flowers on monoecious plants of cucurbits, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about a specific phytohormone that causes the replacement of female flowers with male flowers in monoecious plants, particularly in cucurbits.

2. **Identifying the Options**: The options provided are:
- IAA (Indole-3-acetic acid)
- Cytokinins
- GAs (Gibberellins)
- ABA (Abscisic acid)

3. **Understanding Monoecious Plants**: Monoecious plants have both male and female flowers on the same individual. In cucurbits, this characteristic is important for understanding how flower development can be manipulated.

4. **Role of Gibberellins**: Gibberellins (GAs), specifically gibberellic acid, are known to influence flower development. They can promote the formation of male flowers in plants that are genetically female.

5. **Conclusion**: Based on the role of gibberellins in flower development, the correct answer to the question is GAs (Gibberellins), as they are responsible for replacing female flowers with male flowers in monoecious cucurbits.

### Final Answer:
The phytohormone that replaces female flowers with male flowers on monoecious plants of cucurbits is **GAs (Gibberellins)**.

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