NEET BIOLOGY

Detailed explanation-1: -When any plane passing through the central axis of the body divides the organism into two identical halves, it is called radial symmetry. Coelenterates, ctenophores and echinoderms have this kind of body plan (Figure 4.1a).

Detailed explanation-2: -Phylum Coelenterata, Echinodermata and Ctenophora are exhibit radial symmetry.

Detailed explanation-3: -Coelenterata is the phylum of acoelomate and radially symmetrical lower invertebrates Due to their radial body symmetry they are also known as radiata. Bilateral symmetry starts from the phylum platyhelminthes.

Detailed explanation-4: -Radial symmetry is found in the cnidarians (including jellyfish, sea anemones, and coral) and echinoderms (such as sea urchins, brittle stars, and sea stars).

Detailed explanation-5: -For example, pies, snowflakes, and starfish are radially symmetric because they have many different lines of symmetry (dividing them into matching halves) and the lines cross one another at the center.