What are the reasons that you can think of for the arthropods to constitute the largest group of the animal kingdom?

Explanation

### Step-by-Step Solution:

1. **Understanding Arthropods**: Arthropods belong to the phylum Arthropoda, which is the largest group in the animal kingdom, constituting about 80% of all animal species.

2. **Jointed Legs**: One of the primary reasons for the success of arthropods is the presence of jointed legs. This anatomical feature allows them to move efficiently and adaptively in various environments, particularly on land.

3. **Hard Exoskeleton**: Another significant reason is the presence of a hard exoskeleton made primarily of chitin. This structure provides protection against predators and environmental hazards.

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