| A | B |
|---|
| radial symmetry | arrangement of body parts around a central axis - resembles a cut pie |
| bilateral symmetry | arrangement of body parts so there are distinct left and right halves |
| dorsal | the top or back surface |
| anterior | the front or head end |
| ventral | the bottom or belly surface |
| caudal | the tail end |
| cephalization | the concentration of sensory organs at the anterior end |
| coelom | a true body cavity |
| ectoderm, mesoderm, endoderm | the germ layers of organisms |
| characteristics of chordates | dorsal nerve cord, notochord, pharyngeal pouches |
| invertebrates | animals without a backbone |
| vertebrates | animals with a backbone |
