Answer:
Fermentation
Step-by-step explanation:
I think there is a typo in the question as it doesn't make sense to breakdown oxygen - do you mean the proces of breaking down sugar?
Fermentation vis a type of anaerobic respiration, meaning it occurs in the absence of oxygen. It occurs when sugar is broken down into ethanol and carbon dioxide. It is used to produce alcoholic drinks like beer and wine, and in the production of bread.