| A | B |
|---|
| organism | living things |
| vertebrates | animals with backbones |
| invertebrates | animals without backbones |
| exoskeleton | hard outer covering that protects an animal's body and gives it support |
| fish | vertebrate that lives in water and breathes through gills |
| gills | the feathery parts on the side of a fish's head and allows the fish to breathe underwater |
| amphibian | vertebrate that lives in water until after hatching, then lives on land as an adult |
| reptile | a vertebrate that has dry, scaly skin and lays eggs that have leathery shell |
| bird | vertebrate that has wings and are covered with feathers |
| mammals | vertebrates that feed milk to their young and have hair |
| molts | to shed |
