Cyanobacteria:Photosynthetic bacteria that were the first organisms to produce oxygen as a waste product, paving the way for the Great Oxygenation Event.
Aerobic Respiration: A metabolic process that uses oxygen to efficiently convert organic molecules into energy, enabling more complex lifeforms to evolve.
Banded Iron Formations:Sedimentary rock layers formed when the initial oxygen produced was absorbed by dissolved iron, before the atmosphere became permanently oxygenated.