Jointed legs is the characteristic feature of which phylum?

Options

A. Arthropoda
B. Annelida
C. Nematoda
D. Echinodermata

Answer

### Step-by-Step Solution:

1. **Identify the Key Feature**: The question asks about the characteristic feature of jointed legs.

2. **Recall the Phyla**: Consider the different animal phyla and their characteristics. The main phyla to consider are Arthropoda, Annelida, Nematoda, and Echinodermata.

3. **Analyze Arthropoda**: In the phylum Arthropoda, organisms are known for having jointed appendages, including legs. This phylum includes insects, arachnids, and crustaceans.

4. **Differentiate Other Phyla**:
- **Annelida**: These are segmented worms that do not have jointed legs; they have parapodia or setae for movement.
- **Nematoda**: These roundworms have a different structure for movement, often using cilia-like substances.
- **Echinodermata**: This phylum includes marine animals like starfish and sea urchins, which do not have jointed legs but have other structures for movement.

5. **Conclude**: Since jointed legs are a defining feature of the phylum Arthropoda, we can conclude that the answer to the question is Arthropoda.

### Final Answer:
Jointed legs are characteristic features of the phylum **Arthropoda**.

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