Answer:
To answer this question, we need to understand the characteristics of each of the given substances and identify which one fits the description of an organic substance that can withstand environmental extremes and cannot be degraded by any enzyme. Let's evaluate each option:
Lignin:
- Lignin is a complex organic polymer that provides structural support to plant cell walls.
- It is highly resistant to degradation by enzymes, making it difficult to break down.
- However, lignin can be degraded by certain microorganisms under specific conditions, so it does not fit the given description.
Cellulose:
- Cellulose is another complex organic polymer that forms the primary structural component of plant cell walls.
- While cellulose is resistant to degradation by many enzymes, certain microorganisms and animals possess the enzyme cellulase, which can break down cellulose.
- Therefore, cellulose does not meet the criteria mentioned.
Cuticle:
- Cuticle refers to a waxy, waterproof layer that covers the surface of leaves, stems, and other plant parts.
- While it provides protection against environmental extremes such as drought and UV radiation, it can be degraded by specific enzymes called cutinases.
- Hence, cuticle does not fit the given description.
Sporopollenin:
- Sporopollenin is a highly resistant organic substance found in the walls of pollen grains and spores.
- It is extremely durable and can withstand harsh environmental conditions, including extreme temperatures, high UV radiation, and chemical exposure.
- Sporopollenin cannot be degraded by any known enzyme, making it highly resistant to biodegradation.
- Therefore, sporopollenin is the correct answer to the given question.
In conclusion, the organic substance that can withstand environmental extremes and cannot be degraded by any enzyme is sporopollenin (option D).