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The Complete AP Biology Review Guide for 2019

Posted by Samantha Lindsay | Oct 3, 2018 4:00:00 PM

Advanced Placement (AP)



Reviewing for the AP Biology exam can seem daunting. There's so much material to cover, and much of it is highly complex. However, if you plan your time well and use appropriate study materials and strategies, you can expect a great score on the exam. In this article, I'll give you an overview of what the AP Biology exam is like, what you need to know to ace it, and how you can use your study time effectively before the exam on Monday, May 14, 2018 at 8 am! 


What’s the Format of the AP Biology Exam?

The AP Biology Exam is a long test, three hours long to be exactLike other AP tests, it has two parts, a multiple-choice section and a free-response section (each of which is worth 50 percent of your score), although these sections are divided further into different types of questions.

The multiple choice section has 63 actual multiple-choice questions and six grid-in questions, which are essentially short-answer math problems. This section is one hour and 30 minutes total. Each multiple choice question has four choices, down from five in earlier versions of the exam. 

Even though you technically have more than a minute for each question, I would recommend keeping your time under a minute per multiple-choice question on your first pass through the section. You should also take into account the fact that the grid-in questions may be more time-consuming. There is no guessing penalty, so you should answer every question even if you have no idea which choice is correct (after you’ve tried to figure it out of course!).

The free-response section has eight questions total: six short-response questions and two long-response questions. This section takes up the remaining hour and thirty minutes of time. There is a 10 minute reading period at the beginning of the free response section. You’ll need to pace yourself wisely on this section as well. Try to spend no more than five minutes on each short free-response question. Even though they technically come after the long questions, I’d recommend doing the short questions first to get yourself warmed up. If you manage your time well, you’ll have at least 20-25 minutes left for each of the long free-response questions. 

Here's a chart showing the format of the exam.


Multiple-Choice Section

Free-Response Section


90 minutes

90 minutes

Number of Questions

63 multiple choice

6 grid-in

6 short response

2 long response

Percentage of Total Score





body_marathon-3.jpgThe AP Biology exam is a marathon, not a sprint. If it helps, during the test you can think about how lucky you are to be taking a test and not running an actual marathon.


What Do Questions Look Like on the AP Biology Exam?

Here’s an example of a multiple-choice question you might see on the AP Biology exam:


You don’t necessarily need lots of in-depth biology knowledge to answer this. The answer is A because the total volume of gas wouldn’t change (and oxygen consumption would be unmeasurable) unless the carbon dioxide produced by the organisms was removed from the environment. You can see this from the information contained in the question. This question is part of a group of three questions that pertain to the experiment and data chart. You’ll see many question clusters like this in the multiple-choice section.  


Here's an example of a grid-in question:


The grid-ins are usually straightforward math problems that relate to biological concepts (the answer to this question is 60). Note that you are allowed to use a calculator on the exam, and you’ll get a list of formulas that pertain to the course along with your testing materials.


Here’s an example of a short free-response question from the 2013 exam:


This question requires an understanding of how evolution shapes the formation of new species (one of the “Big Ideas” of AP biology, which I’ll talk about in the next section). To get the correct answer, you have to know the facts about evolution, but you also need to be able to apply that knowledge to make inferences about this specific scenario. This is why a deeper understanding of the main topics in AP Biology is so critical - the difference between knowing the facts about something and comprehending how it works can be surprisingly large. 


Here’s an example of a long free-response question:


This question is also heavier on analysis than straight up biology knowledge. You need to be able to read and understand the graphs and table so you can use them to inform your answer to the question. Once again, an understanding of evolution and the ability to apply that knowledge to a specific scenario is critical.

What Topics Does the AP Biology Exam Cover?

The College Board says in its Course Description that AP Biology has changed its focus from the more memorization-based curriculum that defined the course and exam in the past. The goal is for students to gain a deeper conceptual understanding of topics in biology. Reasoning skills and knowledge of the process of scientific inquiry are more important on the current AP Biology test than they have been before. 

The College Board has tried to structure the exam so that content knowledge and reasoning skills are intertwined. This can be both good and bad: the good is that you won’t necessarily have to memorize as many little tidbits of information, the bad is that it can be harder to study for a test like this that covers more abstract forms of knowledge. More on how to manage this in the “How to Review” section! 

The exam and curriculum as a whole will be centered around your understanding of these four “Big Ideas,” which each cover a bunch of different topics. Your success on the exam rests on being able to connect specific concepts with the overarching Big Ideas that define the course. 


Big Idea 1: The process of evolution drives the diversity and unity of life


  • Natural selection
  • Hardy-Weinberg
  • Biodiversity and categorization of organisms


body_darwin.jpgCharles Darwin married his first cousin. You'd think he would know better.


Big Idea 2: Biological systems utilize free energy and molecular building blocks to grow, to reproduce and to maintain dynamic homeostasis


  • Molecular biology
  • Biological systems and reactions
  • Photosynthesis
  • Cellular respiration
  • Cell structure
  • Cell membrane properties (diffusion and osmosis, proteins)
  • Thermodynamics/homeostasis
  • Immune response


body_sunflower.jpgPhotosynthesis is way more elegant than eating. Then again, flowers will never taste ice cream, so I kinda feel sorry for them.


Big Idea 3: Living systems store, receive, transmit and respond to information essential to life processes


  • Genes and gene mutations
  • Cell cycle (mitosis, meiosis) and cell communication
  • Mendel and laws of inheritance
  • Viruses
  • Endocrine system
  • Nervous system


body_dna.jpgDeoxyribonucleic acid: It's DNAmazing!™


Big Idea 4: Biological systems interact, and these systems and their interactions possess complex properties


  • Enzymes
  • Plant structure and systems
  • Circulatory system
  • Digestive system
  • Musculoskeletal system
  • Ecological principles



Fun digestive system fact: If you eat a watermelon seed, a watermelon will grow inside your stomach. The ideal climate for watermelon growth is 96 degrees and highly acidic.


Apart from background knowledge of this content, it’s also important to understand your labs and the basic underlying principles that govern scientific experiments. If you know the ins and outs of experimental design, you’ll earn a lot of points on the exam. I recommend the CliffsNotes AP Biology 4th Edition review book as a helpful resource for going over labs, but you should also look back at what you did in your class. I'll provide more details on this in the next few sections.


Important Lab Topics Include:

  • Artificial Selection
  • Modeling Evolution
  • Comparing DNA Sequences
  • Diffusion and Osmosis
  • Photosynthesis
  • Cellular Respiration
  • Mitosis and Meiosis
  • Bacterial Transformation
  • Restriction Enzyme Analysis of DNA
  • Energy Dynamics
  • Transpiration
  • Animal Behavior
  • Enzyme Catalysis

body_microscope.jpgMicroscopes show us that the world around us is far creepier and grosser than we ever imagined.


AP Biology Review Preview: Important Tips to Keep in Mind

In this section, I'll give you some preliminary study tips that will help you get the most out of your AP Biology review time.   


Tip 1: Plan Out Your Time 

First of all, you should think about how much time you have left before the AP test. This will affect the structure of your study plan. If you're taking other AP classes or have a lot of commitments in general, you might want to start earlier depending on your confidence with the material. Consider your schedule and the time you're willing to spend on AP Biology. Since there's so much content in this course, I think 20 hours of studying is a reasonable goal. However, if you find that you're already scoring at a high level (a high 4 or anywhere in the 5 range), you might aim for just 10 hours or so. 

You should balance your time relatively evenly between studying the material and taking practice tests. In AP Biology, you might benefit from devoting a bit more time to practice testing. Since the test is now more targeted towards assessing analytical skills, practicing real AP questions may help you more than memorizing content (although both are still important!). I'll give you more information about how to use practice tests and review materials effectively in the next few sections. 


Tip 2: Use Appropriate Review Materials

The importance of using the right review materials can’t be overstated, especially in the case of AP Biology. With the recent changes to the test, it’s critical that you don’t use old study materials and assume they will give you all the tools you need to succeed in the new format. From reading student feedback on many AP Biology review books, it seems like some prep companies have struggled to adapt their practice questions and review methods to this version of the test. However, there are still resources out there that can help you. 

Review books that people found most useful include CliffsNotes AP Biology 5th Edition for content review and Sterling AP Biology Practice Questions for practice questions that will give you a good sense of what the new test is like. Pearson's Preparing for the AP Biology Exam book also has some good reviews and may be a nice source of practice free response questions.

Strangely enough, the most popular prep companies, like Princeton Review and Barron’s, have been less successful in updating their review materials to match the new test. If you get their review books, you should supplement them with practice questions from other sources. Avoid using practice questions that come from exams before the 2013 test, when the changes were implemented. You might still be able to use them to refresh your memory on certain topics, but they won’t really prepare you for the more analytical framework of questions on the current test.


Tip 3: Memorization Isn’t Enough

Even though AP Biology still involves a fair amount of memorization, you shouldn’t focus exclusively on content knowledge and assume you’ll do great on the test. Questions will test your critical thinking skills and logical reasoning abilities along with your knowledge of biology. That’s why it’s so important to spend a significant amount of time doing practice questions in addition to content review. Don’t let the test surprise you!


Tip 4: Don’t Forget About Labs

Revisiting old labs is not super fun (well, it wasn’t for me), so you might be tempted to ignore them and just focus on studying content outside of the lab context. Try to avoid this temptation! Go through your labs, and make sure you understand their methodologies and the reasoning behind the results. Understanding the scientific method and the components of a good experiment is absolutely key on the AP Bio exam. The more lab review you do, the more comfortable you'll feel during the test. 

body_flask.pngRemember the lab where you melted down entire trees into a mysterious green serum? No? Well then, you better get studying!


How to Review for the AP Biology Exam

When you're studying for the exam, follow the five steps below to make sure your AP Bio review is as effective as possible.


Step 1: Take a Diagnostic Test

The first step of your AP Biology review is to take a practice exam so you can see how much you’ll need to study (and which areas need the most work). You should take your first complete practice test no later than the beginning of your second semester. You can use a practice exam from a review book or search online for a practice test. The review books I mentioned in the previous section have some good materials. 

When you take a practice test, make sure it’s the new version of the exam. If you see practice tests that have 100 multiple choice questions in the first section, you’re looking at an old version of the AP Biology Exam. You won’t be able to rely on your scores on this version to get a clear picture of where you fall on the new test.


Step 2: Calculate Your Score and Set a New Goal

Once you’ve taken a diagnostic test, you can calculate your score on the 1-5 AP scale. According to the CliffsNotes review book that I mentioned above, you can calculate your score using the following method:

  • Multiply the number of questions you answered correctly in section 1 (multiple choice and grid-in) by 0.725
  • Multiply the number of points you earned in section 2 by 1.25
  • Add those two numbers together to get your raw score

Then convert the raw score to an AP score:

Raw Composite Score

AP Score












For example, if you got 42 questions correct on the multiple choice/grid-in section and earned 25 points on the free response section, your raw score would be (42*.725) + (25*1.25) = 61.7 = just barely made it into the 5 category! This is without taking the curve into account, which is different every year, but it should give you a rough idea of where you stand. Unless you’re scoring a really high 5 (90+), you should still put in a bit of study time to make sure you’re fully prepared.

If you score low (a 1 or a 2), you might make it your goal to raise your score to a 3. Just keep in mind that some schools don't accept 3s for college credit, so you may want to aim higher after you make it to this first milestone. Most colleges consider a 4 to be the standard cutoff for AP credit, so you should try for at least a 4 if you're hoping to get a head start in college. Once you're consistently scoring in the 3 range, you can set a 4 or 5 as your goal.

Even if you’re already at the 4 or 5 level, you probably still have some room to improve. It’s nice to get in some extra practice so that you feel very comfortable on the real test. Depending on how much you need to improve and how long you want to spread out your studying, you might come up with different plans. To improve by one AP score point, you can get away with studying only two months or so in advance. If you’re hoping to improve by 2 or more AP score points, you should try to start midway through the school year if you want to avoid cramming.


body_confidence-1.jpgConfidence is key. If you need to wear a business suit to the test to make yourself feel in control, go for it (I am not responsible for the relentless mocking you will endure from your peers). 


Step 3: Analyze Your Mistakes

This is the most critical part of the review process, and it’s particularly important for AP Biology. There’s a lot of material to learn, and you don’t want to waste time going over concepts that you already have down. Comb through your mistakes on the diagnostic test to see where the most errors happened and why. Did your problems center more around lack of knowledge of background information or difficulty analyzing the scenarios presented to you on the test (you knew the information, but you couldn’t get the question because it confused you)? 

You will most likely have a little of each type of problem, but if one is more prevalent than the other, you should take that into account for your studying strategy. For example, it wouldn’t be a good idea to keep drilling yourself on basic content knowledge if most of your mistakes came in the form of misinterpreting complex questions or reading diagrams incorrectly. You would want to devote less of your time to reviewing biological terms and more of your time to doing real practice questions. 

Even in those cases, you’ll probably still have at least a few issues with content knowledge. As you go through your mistakes, keep a running list of the ideas you need to revisit in your notes or review book. If you’re caught off guard by your unfamiliarity with a certain topic, you should pay special attention to that topic in your studying. You may also notice mistakes due to carelessness or time pressure that aren’t directly related to your knowledge of the material or understanding of the question. In this case, you'll need to think about revising your basic test-taking strategies. In the next step, I’ll go into more detail on this.


body_detective-1.pngDo some practice test detective work! I think this is a detective. Either that or a random guy smoking a pipe and trying to figure out how bad the pimple on his nose looks.


Step 4: Fix Your Mistakes

There are a few things you can do to revise your strategies for taking the exam and effectively review concepts that you didn’t understand. The obvious first step is to go back into your textbook, your notes, or a reliable review book (or even all three!) and brush up on the information you forgot. Sometimes for biology, this is a little overwhelming because of the complexity of the material.

If you’re trying to understand systems or processes, I’d recommend testing yourself by drawing diagrams of how they work. This will allow you to make connections between dry facts presented in the text and the biological reality of what’s happening in the system. It will help you not only in your content knowledge but also in your ability to analyze related scenarios on the test. You can use this strategy for many concepts in AP Biology, and it will make them much simpler to understand. 

To correct your other mistakes that have more to do with question comprehension, you'll need to focus on doing similar practice questions. I’d recommend getting this book of Sterling AP Biology Practice Questions for some questions that are organized logically by topic area and well-aligned with the new exam format. More practice is also a good remedy for careless errors and time management problems. You can learn how to better identify the key parts of each question and avoid distractions that might throw you off.

Underlining the most important parts of the question can be a good strategy if you’re prone to careless errors. If time management is a problem, put some thought into why you ran out of time. Did you linger for too long on difficult questions? Remember, it’s a smart idea to skip questions that are giving you a lot of trouble (not answerable within a minute) and come back to them later once you’ve gotten through the whole section. 


body_practice-10.jpgPractice makes perfect. Maybe you can compose an AP Biology song to help you remember stuff. "Now enzymes....BREAK IT DOWN!" 

Step 5: Take Another Test and Repeat Previous Steps

Now that you’ve analyzed and fixed your mistakes on the diagnostic test and done some more targeted studying, it’s time to take another practice test. Score the new test, then repeat steps 3 and 4. You should notice improvements as you continue to repeat this process and gain familiarity with the format and content of the test.

If you don’t notice positive changes from one test to the next, it may be time to reevaluate your review techniques. Depending on how early you start studying and how much you want to improve, you might go through these steps once, twice, or seven times. You can continue the process until you achieve your score goals or run out of study time!  



The AP Biology test is a long exam, and it covers a wide range of material. Recently, the test was updated to focus less on information recall and more on analytical thinking, which can be good and bad. You won't have to rely on memorization as much, but your score will be highly dependent on your ability to think through complicated scenarios that are presented on the test.

In your AP Biology review, you should still go over all of the information you learned in the course. However, you should also devote a significant amount of your time to practice testing so that you can learn to think the way the test wants you to think. If you plan your study time wisely and learn how to solve the types of questions that are most difficult for you, you'll be on your way to a great score!


What's Next?

Wondering exactly how much time you have before your AP tests? Here are the AP test dates and times for 2019.

If you're in AP Biology, you may think about taking the Biology SAT Subject Test as well. Find out the difference between AP tests and SAT Subject Tests and which are more important for college. 

Considering an AP Calculus course? Read this article for some guidance on deciding whether you should take AP Calculus AB or BC.


Want to improve your SAT score by 160 points or your ACT score by 4 points? We've written a guide for each test about the top 5 strategies you must be using to have a shot at improving your score. Download it for free now:

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Samantha Lindsay
About the Author

Samantha is a blog content writer for PrepScholar. Her goal is to help students adopt a less stressful view of standardized testing and other academic challenges through her articles. Samantha is also passionate about art and graduated with honors from Dartmouth College as a Studio Art major in 2014. In high school, she earned a 2400 on the SAT, 5's on all seven of her AP tests, and was named a National Merit Scholar.

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