Which characteristics of the skeleton of members of phylum echinodermata is unique compared to the typical skeletons of members of clade protostomia? echinoderms have a hard, calcareous skeleton. echinoderms have an internal skeleton. the skeleton of echinoderms provides body rigidity. the skeleton of echinoderms is not molted?

Below are the characteristic of Echinoderms :

Echinoderms have a hard, calcareous skeleton. 

The skeleton of echinoderms is not molted

The qualities of grown-up echinoderms are the owner of a water vascular framework with outside tube feet and a calcareous endoskeleton comprising of ossicles associated by a work of collagen strands.

Answer;

B. Echinoderms have an internal skeleton.

Explanation;Echinoderm is a group of organisms that is made up of invertebrate marine organisms that belongs to the phylum Echinodermata. These organisms are characterized by a hard, spiny covering or skin. They include organisms in classes Echinoidea, such as sea urchins, class Crinoidea, such as sea lilies, etc. Among the characteristics of Echinoderms includes, five-part radial symmetry around a central disk, internal skeleton, unique water vascular system, they have no heart, brain nor eyes, etc.