<span> Oxygen is produced by plants and green-blue algae and consumed by weathering and burning. And yes, also by animals breathing, but that's actually pretty marginal. Oxygen levels are far from constant. There is evidence that in the last 500 million years it fluctuated between 15% and 30% percent.
Hope it helps Basically write about the production of proteins molecules through transcription and translation and talk about the words listed, what them mean, and how they contribute.
