Part of exine where sporopollenin is not present are called

Options

A. Germ pores
B. Sporopollen
C. Generative part
D. None of these

Answer

### Step-by-Step Solution:

1. **Understanding the Structure of Pollen Grains**:
- Pollen grains are composed of two layers: the outer layer called the exine and the inner layer called the intine. The exine is known for its durability and is primarily made of a substance called sporopollenin.

2. **Identifying the Role of Sporopollenin**:
- Sporopollenin is one of the most resistant organic materials known and provides protection to the pollen grains from environmental factors. It is present in the exine, except in certain specific areas.

3. **Recognizing Germ Pores**:
- The parts of the exine where sporopollenin is absent are referred to as germ pores. These are small openings that allow for the emergence of the pollen tube during fertilization.

4. **Conclusion**:
- The correct answer to the question is that the parts of the exine where sporopollenin is not present are called **germ pores**.