A new study reveals that the aerobic nitrogen cycle in the ocean may have occurred about 100 million years before oxygen began to significantly accumulate in the atmosphere, based on nitrogen isotope ...

Photosynthesis, the natural process of converting sunlight energy into chemical energy and generating molecular oxygen, is a ...

Life on Earth possesses an exceptional ability to self-reproduce, which, even on a simple cellular level, is driven by ...

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This process requires specialized organs such as the lungs or gills. This oxygen is used for cellular respiration and metabolism, a byproduct of which is carbon dioxide.