Replies to: What does credit hours mean? A class is usually 3 to 5 credit hours, which roughly refers to the number of hours of lecture per week. For example, a 3-hour class would meet MWF for 50 minutes or TuTh for one hour and 15 minutes. A 5-hour class might meet everyday for 50 minutes, e.g. foreign languages.
The answer is not as complicated as some people may think and yet the method is very effective, even fatal to the predator at times. All jellyfish have tentacles which they use to not only navigate and sometimes swim depending on the species but to also protect themselves from harm.These tentacles are used by the jellyfish to sting those who are preying on them.he answer is not as complicated as some people may think and yet the method is very effective, even fatal to the predator at times. All jellyfish have tentacles which they use to not only navigate and sometimes swim depending on the species but to also protect themselves from harm.
Like the hydra, the jellyfish has a nervous system characterized by a series of interconnected nerve cells (a nerve net). The nerve net surrounds the whole body of the jellyfish. Shown to the left is a statocyst. When the animal moves and body is tilted, the statocyst makes contact with the cilium.he nervous system of the starfish is very simple...there is no brain and there are not even any ganglia to coordinate movement. The nervous system is characterized by a nerve ring that surrounds the mouth. A radial nerve branches off of the nerve ring and extends to each arm.