Which one of the following is resistant action ?
(a) Pollen exine
(b) Leaf cuticle
(c) Cork
(d) Wood fibre

Options

A. Pollen exine
B. Leaf cuticle
C. Cork
D. Wood fibre.

Answer

To solve the question "Which one of the following is resistant to enzyme action?", we need to analyze each of the given options:

1. **Understanding the Options**:
- **(a) Pollen exine**: This is the outer layer of pollen grains, composed of sporopollenin, which is known for its resistance to degradation.
- **(b) Leaf cuticle**: This is a protective layer on the surface of leaves, but it can be broken down by certain enzymes.
- **(c) Cork**: Cork is a protective tissue that can also be susceptible to enzyme action.
- **(d) Wood fibre**: Wood fibers are part of the plant structure but can also be degraded by enzymes.

2. **Analyzing Resistance**:
- Pollen exine is specifically noted for its resistance to enzyme action due to its unique composition of sporopollenin, which is one of the most resistant organic materials known.
- The other options (leaf cuticle, cork, and wood fiber) are not as resistant and can be degraded by enzymes.

3. **Conclusion**:
- Since pollen exine is resistant to enzyme action and the other options are not, the correct answer is **(a) Pollen exine**.

**Final Answer**: (a) Pollen exine

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