| A | B |
|---|
| invertebrates | animals without backbones |
| vertebrates | animals with backbones |
| how animals get nutrients and energy | eating other organisms |
| how plants get nutrients and energy | using chloroplasts to trap sunlight and make food |
| how animal and plant cells are alike | they have a nucleus and special cell parts |
| how animal and plant cells differ | plant cells have a cell wall and chloroplasts |
| the number of species of animals that have been discovered | one and one-half million |
| the major difference scientists use to classify animals into two groups | whether an animal has a backbone or not |
| less than one out of every hundred animal species is this type | mammal |
| about 96 out of every 100 animal species is this type | invertebrate |
| examples of animals with backbones | birds, snakes, frogs |
| examples of animals without backbones | worms, snails, butterflies |
