Question

29.3 Cnidarians Pre-Lab Which specialized cells give cnidarians their name, and what is their function? Cnidarians (phylum Cnidaria) are tubular or bell-shaped animals that live in shallow coastal waters, exce the oceanic jellyfishes. Two basic body forms are seen among cnidarians. The mouth of a polyp is ac upward, while the mouth of a jellyfish, or medusa, is directed dow usa, is directed downward. At one time, both body forms may have been a part of the life cycle of all cnidarians. When both are present the sessile polyp stage pru medusae, and this motile stage produces egg and sperm (Fig. 29.4), Today in some cnidarians, one stage dominant and the other is reduced in other species, one form is absent altogether. Regardless, all chic mare radially symmetrical. absent altogether. Regardless, all cnidarians w coastal waters, except for th of a polyp is directed gure 29.4 The life cycle of a cnidarian. me cnidarians have both a polyp stage and a dusa stage, in others, one stage may be dominant bsent altogether. mouth - tentacle gastro- planula vascular cavity Zygote mesoglea Polyp fertilization mesoglea gastrovascular asexual budding sperm egg cavity mouth of Hydra 5 shows the anatomy of a hydra, which will be ps: there is no alternate stage. Note the the basal disk. A gastro tentacle nexit for

Answer 1

Cnidarians got their name due to the presence of specialized cells called cnidocytes. This cells are also known as stinging cells and its function is in capturing prey by immobilizing it. They do it by injecting the toxin present in these cells to the prey’s body. Location of these cells is in Cnidarian’s mouth and tentacles present around mouth for feeding the prey.