| Question | Answer |
|---|---|
| Cenozoic era | Era of recent life that began about 66 million years ago and continues today includes the first appearance of Homo sapiens |
| Cyanobacteria | Chlorophyll containing photosynthetic bacteria thought to be one of earths earliest life forms |
| Mesozoic era | Middle era of earths history during which Pangea broke apart dinosaur appeared and reptile and gymnosperms were the dominant land life forms |
| Paleozoic era | Era of ancient life which begins about 544 million years ago when organisms developed hard parts and ended with mass extinctions about 254 million years |
| Precambrian time | Longest part of earths history lasting from 4 billion years ago |
