What is the role of germ pore in pollen grain?

Options

A. Emergence of pollen tube
B. Emergence of plumule
C. Emergence of radical
D. Emergence of hypocotyls

Answer

### Step-by-Step Solution:

1. **Understanding Germ Pores**:
- Germ pores are specific openings or apertures found in the exine layer of pollen grains. The exine is the outermost protective layer of the pollen grain.

**Hint**: Remember that germ pores are not solid; they are openings that allow certain processes to occur.

2. **Composition of the Exine Layer**:
- The exine layer is primarily composed of a substance called sporopollenin, which is a robust and protective material. However, at the germ pores, sporopollenin is absent, allowing for these openings.

**Hint**: Think about why the absence of sporopollenin at these points is significant for the pollen grain's function.

3. **Function of Germ Pores**:
- The primary role of germ pores is to facilitate the emergence of the pollen tube during the germination of the pollen grain. The pollen tube is crucial for the transfer of male gametes to the ovule during fertilization.

**Hint**: Consider the importance of the pollen tube in the fertilization process and how the germ pore aids in this.

4. **Conclusion**:
- Based on the above points, we can conclude that the role of germ pores in pollen grains is specifically related to the emergence of the pollen tube, which is essential for the fertilization process.

**Final Answer**: The role of the germ pore in pollen grain is the emergence of the pollen tube.