Which of the following features are common for Cnidaria and Ctenophora?
(a) Exclusively marine
(b) Metagenesis
(c) Tissue level of organisation
(d) Radial symmetry
(e) Diploblastic nature
Both cnidarians and ctenophores are radially symmetrical diploblastic animals with tissue level of organisation. Ctenophores are exclusively marine. Some cnidarians (e.g., Hydra) live in freshwater. Metagenesis is exhibited by cnidarians but not ctenophores.