Movement of pollen tube towards embryo sac is

Options

A. thigmotactic
B. thermotactic
C. chemotropic
D. phototropic

Answer

To answer the question regarding the movement of the pollen tube towards the embryo sac, we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding the Pollen Tube**: The pollen tube is a structure that forms after pollen grains germinate on the stigma of a flower. It serves as a conduit for sperm cells to reach the ovule within the embryo sac.

2. **Identifying the Movement**: The question asks about the type of movement exhibited by the pollen tube as it grows towards the embryo sac. This movement can be influenced by various factors.

3. **Analyzing the Options**:
- **Stigmotactic**: This term refers to movement towards the stigma, which is not applicable here.
- **Thermotactic**: This refers to movement in response to temperature changes, which does not describe the pollen tube's movement.
- **Chemotropic**: This term refers to movement in response to chemical stimuli. The pollen tube grows towards the embryo sac due to chemical signals released by the ovule.
- **Phototropic**: This refers to movement in response to light, which is not relevant to the pollen tube's movement.

4. **Conclusion**: Based on the analysis, the correct answer is **chemotropic**. The pollen tube moves towards the embryo sac due to chemical signals that guide its growth.

### Final Answer:
The movement of the pollen tube towards the embryo sac is **chemotropic**.

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