Which Invertebrate Has an Endoskeleton

Question

Which invertebrate has an endoskeleton?
A) clam
B) lobster
C) sea star
D) earthworm
E) shrimp

Accepted Answer

Sea stars (starfish) are echinoderms, a group of marine invertebrates that possess an endoskeleton made of calcium carbonate. This internal structure provides support and protection, distinguishing them from other invertebrates listed, which either have an exoskeleton or no skeleton at all.