Which one is resistant to enzyme action ?

Options

A. Pollen exine
B. Intine of pollen grain
C. Germ pores
D. Ovule

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which structure is resistant to enzyme action. We need to identify the correct option from the given choices: Pollen Exine, Antine, Pollen Grain, Germ Pores, and Ovule.

2. **Identifying the Structures**:
- **Pollen Grain**: This is the male gamete in flowering plants.
- **Exine**: This is the outer layer of the pollen grain.
- **Antine**: This is the inner layer of the pollen grain, primarily composed of cellulose and pectin.
- **Germ Pores**: These are openings in the exine where sporopollenin is absent.
- **Ovule**: This is the structure that develops into a seed after fertilization.

3. **Analyzing the Pollen Grain**: The outer layer of the pollen grain, known as the exine, is crucial for this question.

4. **Composition of Exine**: The exine is made up of a substance called sporopollenin, which is known for its remarkable resistance to various environmental factors, including enzymatic action.

5. **Properties of Sporopollenin**:
- It is one of the most resistant organic materials known.
- No enzyme has been identified that can degrade sporopollenin.
- It can withstand high temperatures and strong acids.

6. **Conclusion**: Since the exine of the pollen grain is made of sporopollenin, it is resistant to enzymatic action. Therefore, the correct answer to the question is **Pollen Exine**.

### Final Answer:
**Pollen Exine** is resistant to enzyme action.

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