Sporopollenin occurs in

Options

A. Female gametophyte
B. Male gametophyte
C. Vegetative cells of pollen grain
D. Exine of pollen wall.

Answer

**Step-by-Step Solution:**

1. **Understanding Sporopollenin**: Sporopollenin is known as one of the most resistant organic materials found in nature. It is primarily composed of fatty acids and carotenoids.

2. **Location of Sporopollenin**: Sporopollenin is specifically found in the outer layer of pollen grains, which is referred to as the exine. The pollen grain itself consists of two layers: the inner layer called the intine and the outer layer called the exine.

3. **Function of Sporopollenin**: The presence of sporopollenin in the exine serves a protective function. It helps in safeguarding the pollen grain from environmental factors and increases its viability during the process of fertilization.

4. **Analyzing the Options**: The question provides four options:
- A) Female gametophyte
- B) Male gametophyte
- C) Vegetative cells of pollen grain
- D) Enzyme of pollen wall

Based on our understanding, sporopollenin is not found in the female gametophyte, male gametophyte, or vegetative cells of the pollen grain. It is specifically located in the exine of the pollen grain.

5. **Conclusion**: Therefore, the correct answer to the question "Sporopollenin occurs in" is option D) Enzyme of pollen wall, as it refers to the exine of the pollen grain where sporopollenin is located.

**Final Answer**: Sporopollenin occurs in the exine of pollen grain (option D).

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