Dioecious condition prevent autogamy and geitonogamy

Answer

### Step-by-Step Solution:

1. **Understanding Dioecious Condition**:
- Dioecious plants are those that have male and female reproductive structures on separate individuals. This means that one plant will produce only male flowers, while another will produce only female flowers.

2. **Defining Autogamy**:
- Autogamy is a form of self-pollination where pollen from the same flower fertilizes its own ovules. This typically occurs in plants that have both male and female reproductive organs in the same flower (bisexual flowers).

3. **Defining Geitonogamy**:
- Geitonogamy is a type of pollination where pollen from one flower fertilizes the ovules of another flower on the same plant. This also requires the presence of both male and female flowers on the same plant.

4. **Analyzing the Impact of Dioecious Condition**:
- Since dioecious plants have male and female flowers on separate plants, autogamy cannot occur because there are no bisexual flowers to allow self-pollination.
- Geitonogamy also cannot occur because there are no flowers of both sexes on the same plant to allow pollen transfer between them.

5. **Conclusion**:
- Therefore, the dioecious condition prevents both autogamy and geitonogamy because it does not allow for self-pollination or cross-pollination between flowers on the same plant.

6. **Final Statement**:
- The statement "Dioecious condition prevents autogamy and geitonogamy" is **true**.