Bioidentical hormone therapy is often called natural hormone therapy because bioidentical hormones act in the body just like the hormones we produce.But here again, that tricky word natural muddies the waters.ioidentical hormone therapy is often called natural hormone therapy because bioidentical hormones act in the body just like the hormones we produce.
Some bivalves, which are mollusks, have bilateral symmetry. Radial symmetry is typical of starfish, urchins, and sea anemones, which are echinoderms.
Echinoderms exhibit a type of radial symmetry called pentamerous symmetry in which their body can be divided into five equal parts around a central axis. Echinoderms developed this symmetry after they had already diverged from their bilaterally symmetrical ancestors.chinoderms (Echinodermata) are a group of marine invertebrates that includes star fish, sea lilies, feather stars, brittle stars, sea cucumbers and sea urchins.