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Plants produce oxygen by photosynthesis. The Earth's oxygen comes almost entirely from plant life. Of the plants supplying oxygen over haf are alagae in the Earth's oceans.

As to why the oxygen level is maintained at about 21%, this is due to feedback loops in the oxygen cycle involving air and water temperaues, carbon dioxide availability, sunlight and ultraviolet light.

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What level inhaled oxygen?

21% of the air we inhale is oxygen


What is the average oxygen level in air at sea level?

21%


How much oxygen have you got in the air?

The Earth's atmosphere is composed of roughly 21% oxygen. This level of oxygen in the air is ideal for human respiratory needs.


Why does the level of oxygen stay constant?

If you're talking about the level in the air, which I assume you are, it's because as we exhale, the oxygen we inhaled is replaced with carbon dioxide, which trees "breathe" in. Trees, or any plant, then releases oxygen after it completes photosynthesis with the carbon dioxide.


What's the percentage of oxygen in air at sea level to 4 decimal places?

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When air conditioner in vehicle working by closing external air inlet then will the amount of oxygen reduce if how oxygen content is maintained?

The general answer is "no, the oxygen in the vehicle compartment is unaffected by the air conditioning unit". The vehicle is not air-tight so while there may be a small decrease in oxygen content, sufficient oxygen for normal occupant breathing will remain.


What happens to oxygen level at high altitudes?

At high altitudes, the oxygen level in the air decreases because the air is less dense due to lower atmospheric pressure. This reduced oxygen level can lead to symptoms of altitude sickness like fatigue, dizziness, and shortness of breath in individuals not acclimated to the altitude.


What is the percentage of oxygen in earths air?

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What is the average oxygen level in the air at 5000 ft?

The oxygen content of air at any altitude is always about 21%


Why does the level of oxygen decreases on high mountain?

The level of oxygen decreases on high mountains because the air pressure decreases as altitude increases. This decrease in air pressure results in lower oxygen content for each breath taken at high elevations, making it harder for the body to get enough oxygen.


What is the Percentage of oxygen in the air in Denver?

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Where do we get the oxygen from that we breathe in?

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