| A | B |
|---|
| Habitat | Where organisms live, grow, and interact |
| Reptiles | Animals evolved from a species of amphibians |
| Amphibians | Animals that live on land but return to water to reproduce |
| Invertebrates | Animals without a backbone |
| Geologic Time Scale | Division of Earth's history into smaller units |
| Organic Evolution | Gradual change in life-forms through time |
| Cyanobacteria | Among the earliest life-forms through time |
| Species | Group of organisms that reproduce only among themselves |
| Vertebrates | Animals with a backbone |
| Angiosperms | Flowering plants |
| Gymnosperms | Naked seed plants |
| Endangered | State when only a small number of the members of a species are living |
| Natural Selection | Process by which organisms with traits that are suited to a certain environment survive whereas others do not |
