Question

Class Ophiuroidea is characterized by

• A. Absence of arms
• B. Arms with pinnules
• C. Arms sharply marked off from the central disc
• D. Arms not sharply marked off from the central disc

Answer 1

The correct option is C Arms sharply marked off from the central disc

Ophiuroidea is a large group so echinoderms that include the brittle stars (Ophiuroidea) and the basket stars (Euryalida). Ophiuroidea usually has five arms and superficially resembles true starfish. However, they have long flexible arms and a central armoured, disk-shaped body that is clearly demarcated from the arms.
Therefore, the correct answer is option C.