Question

Explain the following cycle in your own words with a suitable diagram. 

Oxygen cycle.

Answer 1

 Oxygen cycle

1. Oxygen is an important component of life. We cannot survive without oxygen. It comprises about 21% of atmospheric air.
2. 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.
3. 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.
4. Oxygen is also a part of several essential bio-molecules such as carbohydrates, proteins, nucleic acids and fats.
5. 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.