Instructions: Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.
Input: Question: Rising and falling levels of what will result in progression of the ovarian and menstrual cycles? Answer: hormones
Output:
Figure 43.17 Rising and falling hormone levels result in progression of the ovarian and menstrual cycles. (credit: modification of work by Mikael Haggstrom).