Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: After puberty, an egg develops in an ovary about once a month. As you can see in Figure below , the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. Answer: follicle
Output:
What is the nest of cell an egg rests in called?