GENERAL HISTOLOGY

Detailed explanation-1: -The echinoderms have a radially arranged, pentamerous body structure that is very different from the bilateral body structure of the related deuterostome phyla, the hemichordates and the chordates.

Detailed explanation-2: -Adults are distinguished by their radial symmetry, which is shared by starfish, sea urchins, sand dollars, and sea cucumbers. They have five bodies, which they call tube feet. The larvae of echinoderms, on the other hand, have bilateral symmetry.

Detailed explanation-3: -n. Symmetrical about an axis that runs from the oral surface where the mouth is to the side opposite the mouth. Cnidarians have radial symmetry. Echinoderms are bilateral animals that have a 5-part radial symmetry as adults.