Q. What does radial symmetry means? What is the kind of symmetry found in chordates? Which are other phyla of the animal kingdom that present species with radial symmetry?
Radial symmetry means (biologically) that the animal structures are situated in a circular or radial pattern around a center point with nonexistence of sides, like left or right. An alternative type of symmetry in which structures are placed equally in the sides of a longitudinal axis is the lateral symmetry the symmetry present in human beings, for instance, Chordates present lateral symmetry. Besides cnidarians another animal phylum with species presenting secondary radial symmetry is the phylum Echinodermata, It is considered that the simplicity of poriferans does not characterize any symmetry.