| A | B |
|---|
| annelid | segmented eucoelomate worms |
| oligochaeta | an a worm with a underdeveloped head, few bristles, and fresh water forms |
| leaches | blood sucking invertebrates |
| cocoon | a web like structure |
| polychaeta | bristle worms make up this class |
| pharynx | an extended tubelike muscular organ |
| scolex | the knob-shaped head of a tapeworm |
| proglottid | detachable section of a tapeworm |
| external fertilization | fertilization that occurs in water into which both eggs and sperm have been released |
| medusa | the free-swimming, bell-shaped stage of the life cycle of the cnidarian |
| polyp | the sessile, tube-shapped stage |
| nerve net | conduct nerve impulses, resulting in contraction |
| nematocyst | tiny, harpoonlike structures; are found at the tips of tentacles |
