Which of the following structures guides the pollen tube during its growth so that it may reach the final destination?

Options

A. Conducting stands of style
B. Obturator
C. Filiform apparatus
D. All of these

Answer

To answer the question regarding which structure guides the pollen tube during its growth, we can analyze the options provided:

1. **Understanding the Pollen Tube**:
- The pollen tube is a tube-like structure that grows from the pollen grain after it lands on the stigma of a flower. It serves to transport male gametes to the ovule for fertilization.

2. **Identifying the Structures**:
- **Conducting strands of style**: The style is the part of the flower that connects the stigma to the ovary. It contains conducting strands that facilitate the growth of the pollen tube towards the ovule.
- **Obturator**: This is a structure that helps in guiding the pollen tube, but it is not the primary structure responsible for directing its growth.
- **Filiform apparatus**: This is a specialized structure found in the synergids (which are part of the ovule) that plays a crucial role in guiding the pollen tube to the ovule.

3. **Evaluating the Options**:
- **Option 1 (Conducting strands of style)**: This structure does guide the pollen tube during its growth.
- **Option 2 (Obturator)**: While it has a role, it is not the main guide for the pollen tube.
- **Option 3 (Filiform apparatus)**: This structure also aids in guiding the pollen tube.
- **Option 4 (All of these)**: This option suggests that all three structures play a role in guiding the pollen tube.

4. **Conclusion**:
- The most accurate answer is **Option 4 (All of these)**, as all three structures contribute to guiding the pollen tube to its destination.

### Step-by-Step Solution:
1. **Identify the role of the pollen tube**: Understand that the pollen tube is responsible for delivering male gametes to the ovule for fertilization.
2. **Analyze the structures provided in the options**: Look at each option and determine its role in guiding the pollen tube.
3. **Evaluate the contributions of each structure**: Recognize that both the conducting strands of the style and the filiform apparatus are directly involved in guiding the pollen tube.
4. **Select the correct answer**: Conclude that since all three structures contribute to the guidance of the pollen tube, the correct answer is "All of these".