| Answer | Crossword Clue |
|---|---|
| prelife | Prior to the appearance of life forms on earth |
| earthliest | Of or relating to the earth or human life on the earth |
| earthly | Of or relating to the earth or human life on the earth |
| earthlier | Of or relating to the earth or human life on the earth |
| cyanobacteria | A division of microorganisms that are related to the bacteria but are capable of photosynthesis. They are prokaryotic and represent the earliest known form of life on the earth |
| biospheric | relating to the biosphere, the plant and animal life on the earth |
