| A | B |
|---|
| pharyngeal pouches | paired openings used for breathing |
| endotherm | vertebrates with a constant body temperature |
| endoskeleton | the internal skeleton |
| ectotherm | body temperature changes with environment |
| notochord | structure that supports an animal and becomes backbone in vertebrates |
| chordate | has 4 characteristics, every vertebrate is also this |
| cartilage | tough, flexible tissue |
| postanal tail | muscular structure at end of the developing chordate |
| vertebrae | stack of bones that form the backbone |
| nerve cord | becomes brain and spinal cord |
