Which feature would you find on an echinoderm?

• A. Exoskeleton
• B. Segmented body
• C. Jointed appendages
• D. Radial symmetry

Answer: (D)

Verified step by step guidance

1. Understand the characteristics of echinoderms: Echinoderms are a group of marine animals that include starfish, sea urchins, and sand dollars. They are known for their unique features, which distinguish them from other animal groups.
2. Identify the key feature of echinoderms: One of the most distinctive features of echinoderms is their radial symmetry. This means their body parts are arranged around a central axis, allowing them to be symmetrical in multiple planes.
3. Differentiate radial symmetry from other features: Radial symmetry is different from bilateral symmetry, which is found in animals with a distinct left and right side. Echinoderms do not have an exoskeleton, segmented body, or jointed appendages, which are features of other animal groups like arthropods.
4. Explore the function of radial symmetry: Radial symmetry in echinoderms is advantageous for their lifestyle, as it allows them to interact with the environment from all sides equally, which is useful for sessile or slow-moving organisms.
5. Conclude with the identification of echinoderm features: Based on the characteristics discussed, radial symmetry is the correct feature associated with echinoderms, setting them apart from other groups with exoskeletons, segmented bodies, or jointed appendages.