It is believed that when primitive algae flourished on an early earth, they pumped out zillions of cubic kilometres of this gas. Before them, oxygen wasn't around in the atmosphere in very large quantities. After long, long periods of time, the percentage of oxygen in the atmosphere rose. It is to these early life forms that we owe the "air" and the atmosphere that supports us now.
The first oxygen in Earth's early atmosphere was produced by photosynthetic bacteria around 3.5 billion years ago. These bacteria released oxygen as a byproduct of their metabolic processes, gradually increasing the oxygen levels in the atmosphere over millions of years.
carbon dioxide
Banded iron formations indicate that there were oxygen-rich and oxygen-poor episodes during Earth's early atmosphere. Banded iron formations first appear in the Archean, 3 billion years ago. Unbanded iron deposits (red beds) from the Proterozoic, 1.8 billion years ago, indicate that the atmosphere became oxygen rich and that oxygen-poor episodes were no longer prevalent.
The major contributor of oxygen to Earth's atmosphere is cyanobacteria, which are photosynthetic bacteria that produce oxygen as a byproduct of photosynthesis. These organisms were among the first to evolve the ability to perform photosynthesis, releasing oxygen into the atmosphere billions of years ago.
The main source of free oxygen that first entered Earth's atmosphere is believed to be the process of photosynthesis by ancient cyanobacteria, also known as blue-green algae, around 2.5 to 3.5 billion years ago. These microorganisms converted carbon dioxide and water into oxygen and organic compounds, gradually increasing the oxygen levels in the atmosphere.
Oxygen began to accumulate in Earth's atmosphere approximately 2.4 billion years ago during the Great Oxidation Event, brought about by the emergence of photosynthetic organisms that produced oxygen as a byproduct of photosynthesis.
The first oxygen in Earth's early atmosphere was produced by photosynthetic bacteria around 3.5 billion years ago. These bacteria released oxygen as a byproduct of their metabolic processes, gradually increasing the oxygen levels in the atmosphere over millions of years.
The evolution of photosynthetic bacteria and later on, plants, was responsible for changing the formerly poisonous atmosphere to an oxygen-rich one we have today. These organisms released oxygen as a byproduct of photosynthesis, gradually increasing levels of oxygen in the atmosphere.
The first source of oxygen in our atmosphere was likely the photosynthesis of cyanobacteria, also known as blue-green algae. Over time, these microorganisms released oxygen as a byproduct of their metabolic processes, gradually increasing the oxygen levels in Earth's atmosphere.
Life came first. The oxygen in Earth's atmosphere is a product of living organisms carrying out photosynthesis.
The atmosphere is 79.9% oxygen.
21% of the atmosphere is oxygen.
Banded iron formations indicate that there were oxygen-rich and oxygen-poor episodes during Earth's early atmosphere. Banded iron formations first appear in the Archean, 3 billion years ago. Unbanded iron deposits (red beds) from the Proterozoic, 1.8 billion years ago, indicate that the atmosphere became oxygen rich and that oxygen-poor episodes were no longer prevalent.
carbon dioxide
These gases are nitrogen and oxygen.
Early photosynthetic bacteria, such as cyanobacteria, were responsible for changing the formerly poisonous atmosphere to an oxygen-rich atmosphere through the process of photosynthesis. These organisms released oxygen as a byproduct of converting sunlight into energy, which gradually increased the atmospheric oxygen levels over time.
the environment which has the availability of oxygen it is called aerobic atmosphere and if the availability of oxygen is not there in atmosphere then it is anaerobic type We live in a aerobic atmosphere which has the oxygen available