Respuesta :
Answer:
Oxygen cycle, along with the carbon cycle and nitrogen cycle plays an essential role in the existence of life on the earth. The oxygen cycle is a biological process which helps in maintaining the oxygen level by moving through three main spheres of the earth which are:
- Atmosphere
- Lithosphere
- Biosphere
Explanation:
The atmosphere is the layer of gases presents above the earth’s surface. The sum of Earth’s ecosystems makes a biosphere. Lithosphere is the solid outer section along with the earth’s crust and it is the largest reservoir of oxygen.
Answer:
Oxygen cycle, circulation of oxygen in various forms through nature. ... Free in the air and dissolved in water, oxygen is second only to nitrogen in abundance among uncombined elements in the atmosphere. Plants and animals use oxygen to respire and return it to the air and water as carbon dioxide (CO2).
Explanation:

