Answers from Katherine Zeratsky, R.D., L.D. Vitamin D deficiency â when the level of vitamin D in your body is too low â can cause your bones to become thin, brittle or misshapen.
All cnidarians have radial symmetrical. There are two major body forms among the Cnidaria-the polyp and the medusa. Sea anemones and corals have the polyp form, while jellyfish are typical medusae. When you look at them, you can see that these body forms are the same except that one is upside down.
Cnidaria is a phylum containing over 9,000 species found only in aquatic and mostly marine environments. All cnidarians have radial symmetrical. There are two major body forms among the Cnidaria-the polyp and the medusa. Sea anemones and corals have the polyp form, while jellyfish are typical medusae.When you look at them, you can see that these body forms are the same except that one is upside down.nidaria do not have a brain or groups of nerve cells ( ganglia ). The nervous system is a decentralized network (ânerve netâ), with one or two nets present. They do not have a head, but they have a mouth, surrounded by a crown of tentacles. The tentacles are covered with stinging cells (nematocysts).