| Term | Description |
| vertebrate | an animal w/ a backbone |
| invertebrate | in animal w/ out a backbone |
| bilateral symmetry | describes animals w/ body parts arranged in the same way on both sides of their body |
| radial symmetry | describes animals w/ body parts arranged in a circle around a central point; similar to a bicycle wheel |
| sessile | describes organisms, such as trees, that remain attached to one place during their lifetime |
| filter feeder | an organism that obtains food & oxygen by filtering it from the water from which it lives |
| collar cell | in sponges, the lining cells that help move through the sponge by beating of the flagella |
| regeneration | the ability of an organism to replace body parts; a type of asexual reproduction in which a whole new organism grows from just a part of the parent organism |
| hermaphrodite | an animal that produces sperm and egg |
| larva | a young organism that develops between egg and adult stages |
| cnidarian | a phylum of hollow-bidied animals w/ stinging cells |
| tentacles | the arm- like structures that surround the mouth of some organisms and help them to capture food |
| polyp | a vase shaped cnidarian that is usually sessile |
| medusa | a bell shaped cnidarian that is free swimming |
| free living | describes an organism that finds its own food and place to live w/ out depending on another organism; the opposite of a parasite |
| anus | an opening at the end of the digestive tract through which solid wastes leave the body |
| cyst | a young, parasitic worm w/ a protective covering |
