The success of arthropods on land is due to ……………. .

Explanation

**Step-by-Step Solution:**

1. **Understanding Arthropods**: Arthropods are a diverse group of invertebrates that include insects, arachnids, myriapods, and crustaceans. They make up about 80% of the total world population of animals.

2. **Adaptations for Land**: The success of arthropods on land can be attributed to several adaptations that allow them to thrive in various environments, including harsh conditions.

3. **Sclerotized Exoskeleton**: One of the key adaptations is the presence of a sclerotized exoskeleton. This exoskeleton is made of chitin, a tough and flexible protein that provides structural support and protection.

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