NEET BIOLOGY

Detailed explanation-1: -The organisms of phylum Echinodermata consists of spiny skinned organisms. In Greek, Echinos means hedgehog and derma means skin. The organisms belonging to this phylum have an endoskeleton made of calcium carbonate.

Detailed explanation-2: -Although they may appear very different, echinoderms all have two major defining characteristics that set them apart from all other animals: a water vascular system and five-sided radial symmetry.

Detailed explanation-3: -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.

Detailed explanation-4: -Echinoderms are “spiny-skinned” invertebrate animals that live only in marine environments.

Detailed explanation-5: -The most notable characteristic of echinoderms is their radial symmetry, with several arms (usually 5 or more) radiating from a central body. Echinoderms lack a heart, brain, and eyes, but do have a mouth and anus.