You will be given a definition of a task first, then some input of the task.
Given a scientific passage and an answer, generate a question for the given answer.

Passage: Yeasts are crucial for the fermentation process that makes beer, wine, and bread. Fermentation occurs in the absence of oxygen and allows the first step of cellular respiration, glycolysis, to continue. Answer: yeast
Output:
What is crucial for the fermentation progress in making bread?