About the AP Biology Exam

April 8, 2024

AP Biology: Big Ideas

The AP Biology curriculum focuses on four Big Ideas:

  • Big Idea 1: Evolution—The process of evolution drives the diversity and unity of life. 
  • Big Idea 2: Energetics—Biological systems use energy and molecular building blocks to grow, reproduce, and maintain dynamic homeostasis. 
  • Big Idea 3: Information Storage and Transmission—Living systems store, retrieve, transmit, and respond to information essential to life processes. 
  • Big Idea 4: Systems Interactions—Biological systems interact, and these systems and their interactions exhibit complex properties.

AP Biology: Units

The following table lists each of the eight units and the approximate percentage of questions that will be devoted to each unit on the AP Biology exam.

AP Biology: Exam Format

You will have three hours total to complete the AP Biology exam, which consists of the two sections outlined in the following table.

AP Biology: Exam Question Types and Sample Questions

There are three question types on the AP Biology exam: multiple-choice, long free-response, and short free-response.

Multiple-Choice Questions on the AP Biology Exam

There are 60 multiple-choice questions on this exam. Each question will have four possible answer choices, and you need to select the choice that best answers the question. Some questions (in both Section I and Section II of the exam) may require you to use your math skills and the AP Biology Equations and Formulas sheet, which will be provided to you on test day. 

In a water molecule, hydrogen atoms are attached to oxygen atoms through which type of bond? 

(A) hydrogen bond
(B) nonpolar covalent bond 
(C) polar covalent bond 
(D) ionic bond

Long Free-Response Questions on the AP Biology Exam

Of the six free-response questions on Section II of the exam, two will be long free-response questions. Each question will be worth between 8 and 10 points, and both will likely involve interpreting and evaluating experimental results. 

Aquatic animals produce carbon dioxide as a product of cellular respiration. Carbon dioxide combines with water to form carbonic acid (H2CO3), which releases hydrogen ions (H+) into solution. Four test tubes (containing 10 mL of water each and different numbers of aquatic snails) are prepared. pH levels were measured in each tube at the beginning of the experiment and after 20 minutes. The results are shown in the following table.

(A) Explain why tubes B, C, and D all had lower pH levels after 20 minutes. 
(B) Identify the independent variable and the dependent variable in this experiment. 
(C) Analyze the data, and predict which tube (B, C, or D) contained 100 times as many H+ ions as that of tube A after 20 minutes. 
(D) Aquatic plants, such as
Elodea, perform cellular respiration, but they also perform photosynthesis. Photosynthesis removes carbon dioxide from the water, reducing the amount of carbonic acid. Predict the effect of adding Elodea to all four tubes at the start of the experiment. Justify your prediction.

Short Free-Response Questions on the AP Biology Exam

Of the six free-response questions on Section II of the exam, four will be short free-response questions. Each question will be worth 4 points, and these questions may involve experimental scenarios, conceptual analysis, analyzing a model or visual representation of a biological concept, and analyzing data.

On hot summer days, misters will sometimes be used to cool participants at outdoor events. 

(A) Describe the property of water that allows misters to have an effective cooling effect. 
(B) Explain why the evaporation of water makes the participants in these events more comfortable. 
(C) Instead of water, nonpolar oil is spread on the skin. Predict whether this would have a less effective cooling effect, a more effective cooling effect, or the exact same cooling effect as water on the skin. 
(D) Using what you know about the comparative properties of water and nonpolar substances, justify your prediction from part (c).

AP Biology: Exam Scoring

The AP Biology exam is scored on a scale from 1 to 5, with 5 being the highest possible score. The following table describes each score.

AP Exam Score



Extremely Well Qualified


Well Qualified




Possibly Qualified


No Recommendation

Scores of 3 or above may earn you college credit or allow you to skip introductory courses and take more advanced courses earlier in your college career. Policies regarding credit for AP exam scores vary widely between schools and may even vary between majors at the same school. Always check with the college or university you plan to attend to find out the latest information. Note that 50% percent of your total score is based on your performance on Section I (the multiple-choice section), and the other 50% of your total score is based on your performance on Section II (the free-response section).