NEET BIOLOGY

Detailed explanation-1: -Mostly sessile animals possess radial symmetry. Sea anemones and “jellyfishes” (members of phylum Cnidaria) possess radial symmetry. Some sea stars (members of phylum Echinodermata ) also possess radial symmetry. Note: Almost all of the radially-symmetrical animals have no front and no back.

Detailed explanation-2: -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-3: -Radial symmetry is an advantage to the sessile or slow moving organisms. Justify this statement. Solution : Animals showing radial symmetry live in water and they can respond equally to stimuli that arrive from all directions. Thus radial symmetry is an advantage to sessile or slow moving animals.

Detailed explanation-4: -Only a few animal groups display radial symmetry, while asymmetry is a unique feature of phyla Porifera (sponges). All types of symmetry are well suited to meet the unique demands of a particular animal’s lifestyle.