The pollen tube enters the ovule through

Options

A. antipodal cells
B. micropyle
C. degenerating synergids
D. all of these

Answer

To solve the question "The pollen tube enters the ovule through," we will analyze the options provided and understand the process of fertilization in plants.

### Step-by-Step Solution:

1. **Understanding the Structure of the Ovule**:
- The ovule is a part of the female reproductive structure in plants. It is located within the ovary and consists of several parts, including the integuments, micropyle, and other cells.

2. **Pollen Tube Formation**:
- When pollen grains land on the stigma of a flower, they germinate and form a pollen tube. This tube grows down through the style towards the ovary.

3. **Pathway to the Ovule**:
- The pollen tube travels through the style and reaches the ovary, where the ovules are located.

4. **Entry Point into the Ovule**:
- The pollen tube must enter the ovule to achieve fertilization. The entry point for the pollen tube is crucial.

5. **Identifying the Correct Entry Point**:
- The micropyle is a small opening in the integuments of the ovule. It is the only point where the integuments are absent, allowing the pollen tube to enter easily.
- The antipodal cells and synergids are parts of the ovule but do not serve as entry points for the pollen tube. The antipodal cells are located at the opposite end of the ovule, and the synergids are adjacent to the egg cell but are not the entry point.

6. **Conclusion**:
- Therefore, the correct answer to the question is that the pollen tube enters the ovule through the **micropyle**.

### Final Answer:
The pollen tube enters the ovule through the **micropyle**.

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