<p> Name ______</p><p>Cnidarians </p><p>17. The phylum Cnidaria includes what organisms? </p><p>18. All cnidarians are ______organisms except for the </p><p>______which is found in freshwater. </p><p>19. Cnidarians all have ______symmetry and </p><p>______or arms that have stinging cells called </p><p>______. These stinging cells shoot out like a </p><p>______and contain a ______that can kill or paralyze their prey. </p><p>20. Cnidarians have _____ body layers; an inner ______and an outer ______. </p><p>21. Cnidarians have ______opening into their hollow bodies called the </p><p>______so food enters and wastes leave through this same opening. </p><p>This is called a ______digestive system. </p><p>22. The hollow cavity the mouth opens into is called the </p><p>______cavity. 23. Cnidarians have 2 body forms. ______forms have the mouth & tentacles located at the top like Hydra, corals, and sea anemones. </p><p>______forms like the jellyfish have their tentacles and mouth located at the bottom. </p><p>24. Some cnidarians like the ______go through both polyp and medusa forms in their life cycle. </p><p>25. Cnidarians have a simple nerve ______and can reproduce both </p><p>______and ______. </p><p>26. Corals build ______cases that make underwater </p><p>______. </p>