What is determined by Pollen-pistil interaction?

Options

A. Compatibility of the pollen
B. Colour of the pollen
C. Nature of the pollen
D. Maturation of the pollen

Answer

### Step-by-Step Solution:

1. **Understanding Pollen-Pistil Interaction**:
- Pollen-pistil interaction refers to the process that occurs when pollen grains land on the stigma of a flower. This interaction is crucial for fertilization to take place.

2. **Initial Contact**:
- When pollen grains fall on the stigma, they must be compatible with the pistil (the female reproductive part of the flower). Compatibility is essential for the next steps to occur.

3. **Growth of Pollen Tube**:
- Upon successful landing on a compatible stigma, the pollen grain germinates and begins to grow a pollen tube down through the style (the elongated part of the pistil). This growth is a response to the chemical signals from the stigma.

4. **Reaching the Ovule**:
- The pollen tube travels through the style and reaches the ovary, where the ovules (which contain the egg cells) are located.

5. **Fertilization**:
- Once the pollen tube reaches the ovule, it releases the male gametes (sperm cells) that can fertilize the egg cell, leading to the formation of a zygote.

6. **Conclusion**:
- Therefore, the pollen-pistil interaction determines the compatibility of pollen with the pistil, which is essential for successful fertilization. If the pollen is not compatible, the pollen tube will not grow, and fertilization will not occur.

### Final Answer:
Pollen-pistil interaction determines the compatibility of pollen with the pistil, which is crucial for successful fertilization.

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