Scientists agree that significant amounts of oxygen were first put into the atmosphere by cyanobacteria which used and still use a process called photosynthesis to convert carbon dioxide and water into sugar and oxygen. The sugar is then used to build cell walls and in the metabolism. When plants evolved, they too carried out photosynthesis, putting even more oxygen into the atmosphere. Prior to the evolution of cyanobacteria, the metabolisms of organism relied on anaerobic processes.
The free oxygen bubbled up from the oceans.
2.2 Billion years ago Photosynthetic bacteria in the ocean began churning out oxygen as a result of photosynthesis. Then, oxygen gas started accumulating in the atmosphere.
The atmosphere in an area where a disease killed all the plants would not have any or very little oxygen. Trees would still produce some oxygen.
78% of the atmosphere is Nitrogen, Oxygen is like 20% Then come the rare gases like Argon, Neon and helium but those are present only in traces.
The majority of oxygen in the atmosphere come from photosynthesis. Aquatic Cyanobacteria (blue green algae) were the first known organisms to use photosynthesis, before there were land plants. The by product of photosynthesis is oxygen. This increase in oxygen eventually allowed organisms to use respiration as a method of energy production. Thus it allowed for land animals.
Oxygen when came in contact with UV broke down. It then reacted with more oxygen to form ozone.
The oxygen most often comes from the atmosphere which is 21% oxygen.
The free oxygen bubbled up from the oceans.
Water molecules are formed by the reaction between hydrogen and oxygen.
It is the Oxygen from the CO2 and H2O tat they use to make sugars.
Plants produce oxygen through photosynthesis and release it into the atmosphere where we can breathe it.
No. Earth's atmosphere most likely originate from volcanic atmosphere. The oxygen is produced by plants.
2.2 Billion years ago Photosynthetic bacteria in the ocean began churning out oxygen as a result of photosynthesis. Then, oxygen gas started accumulating in the atmosphere.
It is diffused from the air, in the atmosphere, and from plant life in the ocean.
Oxygen is part of the mixture of gases we breath. Therefore, burning wood uses the oxygen in the atmosphere.
If you mean how does it come to be in the atmosphere, oxygen is released into the atmosphere by plants, mostly by phytoplankton in the ocean. I you mean how is oxygen created in the first place, it is the result of lighter elements being fused together in the cores of stars.
It is produced by the photosynthesis of plant life.