GENERAL HISTOLOGY

Detailed explanation-1: -Echinoderms are named for their “spiny skin.” However, the spines aren’t on their skin. They are part of the endoskeleton. The endoskeleton consists of calcium carbonate plates and spines, covered by a thin layer of skin. Adult echinoderms have radial symmetry.

Detailed explanation-2: -In addition to radial symmetry, echinoderms have a water-vascular system. True. True or False? The hard, spiny skin of an echinoderm is called an exoskeleton.

Detailed explanation-3: -Note: The echinoderms or the phylum Echinodermata have the presence of spiny skinned animals. They usually have bilateral symmetry and also have the presence of a triploblastic layer. They are mostly marine. Starfish is an example of echinoderm.

Detailed explanation-4: -Spiny skinned animals are placed in Echinodermata. The spines on the skin in echinoderms are part of the endoskeleton. The endoskeleton is made up of calcium carbonate plates called ossicles that bear spines which project outside.