Sporopollenin in exine of pollen grain can be degraded by

Options

A. high temperature
B. low pH (strong acids)
C. some enzyme
D. can't be degraded

Answer

### Step-by-Step Solution:

1. **Understanding Sporopollenin**: Sporopollenin is a complex biopolymer found in the exine layer of pollen grains. It is known for its chemical stability and resistance to degradation.

2. **Structure of Pollen Grain**: The pollen grain consists of two main layers: the exine (outer layer) and the intine (inner layer). The exine is characterized by its tough structure, primarily due to the presence of sporopollenin.

3. **Chemical Properties of Sporopollenin**: Sporopollenin is a chemically inert polymer, meaning it does not easily react with other chemicals or break down under normal conditions. This stability allows pollen grains to survive in harsh environmental conditions.

4. **Degradation of Sporopollenin**: Despite its stability, sporopollenin can be degraded under certain conditions:
- **High Temperature**: Exposure to high temperatures can lead to the breakdown of sporopollenin.
- **Strong Acids**: While sporopollenin is resistant to many substances, it can be affected by strong acids, although this is not the primary method of degradation.
- **Enzymatic Action**: Some specific enzymes may also have the capability to degrade sporopollenin, but this is not common.

5. **Conclusion**: Given the properties of sporopollenin, it is primarily resistant to degradation. However, it can be degraded by high temperatures and potentially by certain strong acids or specific enzymes.

6. **Final Answer**: Sporopollenin in the exine of pollen grain can be degraded by high temperatures, but it is generally resistant to most other forms of degradation.