| A | B |
| the backbone and all the other bones of a vertebrate | skeleton |
| to divide into groups | classify |
| Whales have lungs and breathe _____ | air |
| Most living things are either plants or | animals |
| ______ animals' temperature changes with the surrounding temperature | coldblooded |
| Animals must find _____; most plants make their own. | food |
| animals with backbones | vertebrates |
| animals without backbones | invertebrates |
| ________ animal's temperature stays the same most of the time. | warmblooded |
| Mammals breathe air with _____. | lungs |
| Plants are usually held in the ground by _____. | roots. |