Give scientific reason.
Oxygen is necessary for complete oxidation of glucose.
Glucose can be used by two pathways i.e. aerobic and anaerobic respiration. Glucose is completely oxidised only in the presence of oxygen and results in the release of energy. It undergoes three steps to finally reach its fate - glycolysis, Kreb's cycle and electron transport chain reaction. In anaerobic respiration, glucose undergoes partial oxidation and results in the release of energy which is comparitvely less to the energy released during aerobic respiration.