Sporopollenin occurs in the wall of:

Options

A. Egg cell
B. Pollen grain
C. Synergids
D. Antipodal cells

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks where sporopollenin is found. Sporopollenin is a significant component in the biology of flowering plants.

2. **Identifying the Context**: Sporopollenin is primarily associated with pollen grains. Pollen grains are the male gametes in flowering plants.

3. **Structure of Pollen Grains**: Pollen grains have a hard outer layer known as the exine. This exine is specifically composed of sporopollenin, which gives it its hardness and resistance to environmental factors.

4. **Characteristics of Sporopollenin**: Sporopollenin is known to be one of the most resistant organic materials. It can withstand extreme conditions such as high temperatures and strong acids and bases, and no enzymes can degrade it.

5. **Conclusion**: Based on the information, sporopollenin occurs in the wall of pollen grains, specifically in the exine layer.

6. **Final Answer**: Sporopollenin occurs in the wall of pollen grains.

---