Echinoderms Differ from Mollusks in Their

Question

Echinoderms differ from mollusks in their
A) Dominant radial symmetry
B) Lack of three tissue layers
C) Lack of a calcium carbonate skeleton
D) All of the above

Accepted Answer

Echinoderms, such as starfish, are characterized by their radial symmetry, especially evident in their adult form, which is a key difference from mollusks that generally exhibit bilateral symmetry. Echinoderms do have three tissue layers (triploblastic) and possess a calcium carbonate skeleton, making options B and C incorrect.