explain oxygen cycle

You can refer the diagram given below to understand about Oxygen cycle.

Oxygen is an important component of everyday life. We cannot survive without oxygen. It comprises about 21% of atmospheric air. It is a component of several biological molecules such as carbohydrates, proteins, nucleic acids, and fats.

Like carbon dioxide, oxygen too is cycled through the process of photosynthesis and respiration. Oxygen is also utilized during combustion or burning.

Steps of oxygen cycle.

Step 1)Animals take in oxygen through the process of respiration. And release COinto the atmosphere.

Step 2)Carbon dioxide, released by animals is used in plants in the process of photosynthesis.

Step 3)Plants release oxygen into the atmosphere as a by-product of photosynthesis.

step 4)Fuels need oxygen for combustion so they take oxygen and release COinto the atmosphere as a by product along with other gases like Netc.

Step5)COis released into the air in the process of decaying of dead animals and plants.

step 6)This CO2 is taken by plants for the process of photosynthesis and O2 is released, and this process continues.


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The oxygen cycle is the biogeochemical cycle that describes the movement of oxygen within its three main reservoirs: the atmosphere (air), the total content of biological matter within the biosphere (the global sum of all ecosystems), and the lithosphere (Earth's crust).The presence of atmospheric oxygen has led to the formation of ozone (O3) and the ozone layer within the stratosphere. The ozone layer is extremely important to modern life as it absorbs harmful ultraviolet radiation. Failures in the oxygen cycle within the hydrosphere (the combined mass of water found on, under, and over the surface of a planet) can result in the development of hypoxic zones. The main driving factor of the oxygen cycle is photosynthesis, which is responsible for the modern Earth's atmosphere and life.

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Oxygen Cycle

Oxygen is an important component of life. We cannot survive without oxygen. It comprises about 21% of atmospheric air. It is also present in dissolved form in water bodies and helps in the survival of aquatic life. In combined form, it is found both in Earth’s crust and in the air. In the air, it occurs as carbon dioxide. In the crust, it is present as oxides of most metals and silicon and also as carbonate, sulphate, nitrate and other minerals.

Oxygen is also a part of several essential bio-molecules such as carbohydrates, proteins, nucleic acids and fats.

Oxygen cycle

There are processes that utilize atmospheric oxygen. At the same time, the balance of oxygen in the atmosphere is also maintained.


  • Oxygen is utilized during respiration, combustion and formation of oxides of nitrogen.
  • Oxygen is returned to the atmosphere in only one major way, and that is photosynthesis.
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it is d process by wich oxygen released in2 d atmosphere by photosynthetic organisms is tken up by aerobic organisms wile d carbon dioxide released as a by-product of respiration is tken up 4 photosynthesis... .hope dis helps u

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