Dentist specialties are recognized in those areas where advanced knowledge and skills are essential to maintain or restore oral health. The list of recognized dental specialties differs from country to country.
In contrast, radially symmetrical animals like jellyfish have a topside and a downside, but no identifiable front or back. The bilateria are a major group of animals, including the majority of phyla but not sponges, cnidarians, placozoans and ctenophores. For the most part, bilateral embryos are triploblastic, having three germ layers: endoderm, mesoderm, and ectoderm.
The first type is radial symmetry. With this type of symmetry, the body plan is based around an axis. In other words, the body is oriented so that is radiates out from an imaginary line through the center of the organism.These organisms have a top and bottom, but they don't have a left and right side or a front and back side. A couple examples of radial symmetry are starfish, jellyfish, and sea anemones.n other words, the body is oriented so that is radiates out from an imaginary line through the center of the organism. These organisms have a top and bottom, but they don't have a left and right side or a front and back side. A couple examples of radial symmetry are starfish, jellyfish, and sea anemones.