Question

How does oxygen occur in nature? Explain Oxygen cycle in detail.

Answer 1

Hint: Atmosphere consists of around 20% of oxygen. This is maintained by oxygen cycle. The oxygen from the atmosphere is used up by living organisms and then returned to the atmosphere again.

Complete answer:
Oxygen is one of the major components of the atmosphere. The main importance of oxygen for living organisms is as follows:
a) Atmospheric oxygen is used for breathing by organisms that live on land
b) Oxygen dissolves in water and it is used by aquatic organisms for breathing
c) Decomposition of organic waste also requires Oxygen

The reservoirs where Oxygen is found are Atmosphere, Hydrosphere, Lithosphere and Biosphere. Oxygen circulates through different reservoirs and finally reaches the Atmosphere in a cyclic manner.

The steps in the oxygen cycle are
1) Plants undergo photosynthesis and release oxygen as a byproduct.
2) This oxygen is taken up by animals through respiration process
3) Oxygen is used to breakdown sugars and release energy
4) Animals release carbon dioxide and it returns to the atmosphere
5) Thus Oxygen circulates

Thus the entire oxygen cycle is dependent on two processes: Photosynthesis and Respiration.

Note: The oxygen cycle helps in the movement of oxygen through earth, atmosphere, biosphere and lithosphere. The atmosphere is the largest reservoir of oxygen . Apart from oxygen cycle; the balance of the ecosystem is maintained by many cycles in the atmosphere. These cycles are important for the living of the organism. The other cycles are nitrogen cycle, carbon cycle etc.