Question

echinodermata knowledge check
echinoderms have which type of skeleton?
○ cartilaginous skeleton
○ exoskeleton
○ endoskeleton made of calcium carbonate
○ no skeleton

Explanation:

Echinoderms (like starfish, sea urchins) have an endoskeleton composed of calcium carbonate plates or ossicles. Cartilaginous skeletons are in chondrichthyan fish, exoskeletons are in arthropods, and echinoderms do have a skeleton. So the correct option is the one about the endoskeleton made of calcium carbonate.

Answer:

C. Endoskeleton made of calcium carbonate (assuming the options are labeled A - D as A. Cartilaginous skeleton, B. Exoskeleton, C. Endoskeleton made of calcium carbonate, D. No skeleton)