Pollen prepotency is defined as

Options

A. (1) Preference for foreign pollen
B. Bud pollination
C. Self sterility
D. All of these

Answer

### Step-by-Step Solution:

1. **Understanding Pollen Prepotency**:
- Pollen prepotency refers to the phenomenon where pollen grains from a different flower (foreign pollen) germinate faster than pollen grains from the same flower (self-pollen).

2. **Mechanism of Pollen Prepotency**:
- In this mechanism, when pollen from a different flower lands on the stigma of a flower, it has a competitive advantage over the pollen from the same flower. This means that foreign pollen is more likely to fertilize the ovule than self-pollen.

3. **Role of Autogamy**:
- Autogamy is the process of self-pollination, where pollen from the same flower fertilizes its own ovules. However, in the case of pollen prepotency, autogamy is less favorable because it prevents the germination of pollen from the same flower, favoring the foreign pollen instead.

4. **Self-Sterility**:
- Self-sterility is a condition where the plant has mechanisms to prevent self-fertilization. This is different from pollen prepotency, as self-sterility involves genetic recognition that inhibits self-pollen from germinating.

5. **Conclusion**:
- Therefore, pollen prepotency can be defined as the preference for foreign pollen over self-pollen due to its faster germination and ability to fertilize the ovule effectively.

### Final Answer:
Pollen prepotency is defined as the preference for foreign pollen, which germinates faster than self-pollen.

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