| A | B |
|---|
| vertebrate | animal with an internal segmented backbone |
| invertebrate | animal without a backbone |
| animal phylum | group of animals defined by structural and functional characteristics that are different from every other animal phylum |
| bilateral symmetry | body plan of some organisms in which the body can be divided equally along only one plane |
| radial symmetry | arrangement of body parts in a circle around a central axis |
| protostome | animal development in which the animal's mouth develops before the anus |
| deuterostome | animal development in which the animal's anus develops before the mouth |
