Environmental Studies(ES)

ENVIRONMENTAL STUDIES

Lesson 10: Bio-geo-chemical cycles

Oxygen cycle

Oxygen is absorbed by plants and animals from the air during respiration. The plants return oxygen to the atmosphere during photosynthesis. This links the oxygen cycle to the carbon cycle. Animals absorb oxygen returned by the plants from the atmosphere and release it through cellular respiration. Deforestation is likely to reduce the oxygen levels of the atmosphere.