Question 1 Many species have circadian rhythms that exhibit an approximately 24-hour cycle. Circadian rhythms are controlled by both genetics and environmental conditions, including light.
The AP Biology exam is three hours long, with two sections that take up an hour and a half each. The multiple-choice section has 60 questions, and the free-response section has six questions. The content of the exam spans four major themes, or Big Ideas, that are central to the course.