Explanation

Radial symmetry is the characteristic feature of coelenterates and echinoderms. Section of these animals in two or more planes produces halves which are approximately mirror images of each other. Bilateral symmetry occurs in most metazoans. These have only one plane in which they can be divided into two halves, which are mirror images of each other. In spherical symmetry, the body of the individual can be divided into similar halves by any plane passing through the centre. This type of symmetry is found in Volvox, a colonial green algae.