Final answer:
Fermentation is the process that allows glycolysis to continue producing ATP under anaerobic conditions in yeast cells.
Step-by-step explanation:
Anaerobic conditions in yeast cells can be sustained through a process called fermentation. Fermentation is an alternative pathway that allows glycolysis to continue producing ATP without the need for oxygen. In fermentation, the pyruvate produced by glycolysis is converted into either ethanol or lactic acid, depending on the type of fermentation.