MCAT biology prep can be overwhelming. The amount of biologically-related content makes you question where to start. This definitive MCAT biology prep guide will outline how much biology you can expect on the test day, how to start studying for MCAT biology and give you some foolproof biology study tips. Finally, you will have access to the entire list of biology concepts you can expect on the test in one place, right here!

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How Much Biology is on the MCAT? How to Start Studying for MCAT Biology MCAT Biology Study Tips Appendix: What Biology Concepts Are on the MCAT? FAQs

Check out this video for more tips on how to ace the MCAT Biology Section!

How Much Biology is on the MCAT?

Unsurprisingly, biology is prominently featured in the MCAT. Critical Analysis and Reasoning Skills (CARS) is the only of the four MCAT sections where you should not expect your biological knowledge to be tested. The first section, Chemical and Physical Foundations of Biological System, will have about 30% of biology-related content; section 3, Biological and Biochemical Foundations of Living Systems, will have about 90%; lastly, section 4, Psychological, Social, and Biological Foundations of Behavior, will have about 5%. Each of these three sections will have 59 questions, a combination of passage-based and discrete. You will have 95 minutes to complete each section. And while there is a lot of ground to cover in your biology review, recall that you do not need to be a biologist to ace these sections of the MCAT. To be competent for the exam, we highly advise you to take a variety of biology and biochemistry classes. It might be wise to take more than just intro classes. Some colleges and universities do not cover all the MCAT biology content in intro classes. Research what kind of courses you can take at your university that will help you in preparation for this challenging MCAT topic.

A warning before you start your MCAT biology prep: do not panic when you see the entire list of biology concepts and terminology you should know for the MCAT. You might feel the need to express your frustration and ask questions of your peers on Reddit Premed or Premed101 forums, but these platforms tend to incite even more fear and panic in students. In these forums, you will encounter individuals who will claim that they have read every biology textbook under the sun, who hired multiple tutors to prepare for the MCAT, who had to memorize thousands of terms and concepts before they took the exam – all this can make you question your level of dedication, knowledge, and MCAT prep strategies. If you really need some quality advice, you should reach out to a medical school advisor to discuss your fears and concerns about your knowledge of biology. These professionals can often provide you with valuable advice about what study resources to use and where to seek help for concepts you are struggling with.

How to Start Studying for MCAT Biology

The overwhelming amount of biology on the MCAT can be intimidating but try to remember that thousands of students have overcome this challenge, and so can you. If biology is not your forte, do not panic. Any MCAT prep must begin with an MCAT diagnostic test. It will help you determine how much you already know, which disciplines and concepts you need to focus on, and finally, help you prioritize which topics need your immediate attention. For example, if after the practice test you find that your biology knowledge is lacking, you should try to focus your attention on biology and biochemistry. Why? Because of their prominence on the exam. While MCAT physics takes up only 20%-25% of the second section of the MCAT, biology and biochemistry are featured in every MCAT section with the exception of CARS. So, if you are struggling with biology questions, make sure to include the topics you find challenging in your MCAT study schedule.

When to start studying for the MCAT will depend on whether you have just taken all the necessary intro courses. If you have just taken all the necessary classes, your MCAT prep will be more reminiscent of review and revision. You will most likely quickly recall biology concepts and terminology as soon as you see them on the practice exam. However, if it's been a while since you have been exposed to the study of biology, you must initiate your study prep earlier. Don’t forget that in addition to reviewing biology, you must also pay some attention to MCAT chemistry questions, MCAT psychology questions, and MCAT physics equations during your preparations. In addition to reviewing these scientific and social science topics, you must also get ready for CARS. As many of you know, you cannot get ready for MCAT CARS by memorizing concepts and terminology – you must practice reading challenging texts for months (!!!) and go over MCAT CARS practice passages. This is why having a solid MCAT CARS strategy is key to tackling this challenging section.

MCAT Biology Study Tips

Let’s go over some study strategies you can implement to help you internalize MCAT biology content.

Start Early

Unlike MCAT physics, biology has a much more dominant presence on the exam. There is a large number of biology concepts and topics you will need to review before you take the test. This is why we highly advise you to begin your MCAT prep at least 6 months before your scheduled MCAT test date, especially if it's been a while since you have taken the intro biology and biochemistry courses. After you take a look at all the biology terms, topics, and themes you have to cover, you might be alarmed by how hard the MCAT is. However, if you have the right MCAT study schedule, you will be able to get ready for this challenging exam.

Keep the “Big Picture” In Mind

Keep in mind that the MCAT tests basic scientific knowledge, so do not get bogged down by the details of the passages, questions, and responses. Read the passages carefully but try not to panic if you find that the passage is full of words that are unknown to you. It is almost certain that you will encounter concepts and terminology that are unfamiliar to you – do not worry, the passage is aimed to see whether you can understand the underlying ideas and concepts of biological systems. As you are reading a biology passage, try to get the general gist of what the passage is about and go from there.

Try Highlighting Important Sections of the Passage

When you encounter passages that deal with biological concepts, read the passage carefully, and highlight the most important aspects of the text. Try to take no longer than 4 minutes per passage. As you are reading the passage, try to anticipate what questions they are going to ask you. If you highlight effectively, you will more-or-less have the key to answers right in front of you – you will not need to reread the passage again to find the answer.

Leave External Knowledge Behind the Exam Door

Most likely, you have heard that you should not bring in any external knowledge when you choose your answers for MCAT CARS passages. This is true for most MCAT sections. You may be tempted to choose answers based on your outside knowledge but avoid this temptation. Each question and answer options are tailored to the specific passages you are given. The MCAT is designed to test basic scientific knowledge: if you start bringing in the knowledge that is not related to the passage or the question, you may not be able to find the correct response, panic, and miss an opportunity to increase your score.

Read the Passages, Answers, and Questions correctly. Anticipate Answers Before You Read the Responses

Accurate reading and understanding of MCAT biology passages, questions, and answers are the keys to your success. Pay special attention to graphs, figures, or images you may encounter. Attention to detail may allow you to make predictions before looking at the answers. Then you can simply choose the answer that is closest to what you came up with. If you go straight to reading the responses, you may become overwhelmed – it’s like answering four or five questions instead of answering just one!

Try Skimming Though Questions Before You Read the Passage

This method won't work for everyone; however, as you start your MCAT prep, you may have time to try out different strategies. Some students have noted that skimming through questions (not the responses!) before reading the passages helps them highlight the words that correspond with the keywords in the question. So, after reading the questions, highlight any words in the passages that look familiar – this way, you will not need to reread the passage several times for each question. This kind of practice can help you get better at recognizing relevant and important information in each passage you face.

Make Notes of Weak Areas

Remember, taking as many diagnostic tests as you can during your MCAT prep is one of the best study tactics. Not only do they help you create your MCAT study schedule, but they also help you see if you are improving. As you are going over MCAT biology questions, jot down any topics that you are struggling with or topics you completely missed in your practice test. After you finish practicing with sample biology questions, add to your study plan which content areas you need to review and what kind of study strategies you will implement. For example, if you are lacking knowledge about nucleotide structure, schedule to review corresponding chapters of your textbook and your notes, draw diagrams, and watch helpful video content.

Keep a Log of Wrong Answers

This may seem counterintuitive but keeping a record of what questions you got wrong may be a useful MCAT prep practice for some. In this log, write down the passage and questions you got wrong, along with explanations of the correct answers. For example, if you chose the wrong responses with regards to the structure of a cell, draw a correct diagram of it in your log. If you review the cell structure in detail, you are less likely to get similar questions or topics wrong in the future. For some students, nothing drills the correct answers into their memory more than getting something wrong first. This prompts them to research the correct response and find a detailed explanation of why they were wrong.

Draw the Material

Some students learn quite well by reading, memorizing, and writing down material. Some students, however, learn best in a visual format. Think about drawing your notes, using different colours or highlights, or making flowcharts so you can visualize key concepts, which can make it easier to recall large amounts of information.

Active Learning

Using the study tips above may help you remember the large amount of content you need. However, a great way to know you have really understood it is to teach it to someone else. Recruit a study buddy who is also preparing for the MCAT and take turns explaining key concepts to the other person. Can you explain it so your friend understands? If so, you can be more confident that you know the material well.

Try Reading Difficult Material About Biology

Think of this study tip as killing two birds with one stone. Reading biology-related material in journal articles, newspapers, or magazines will help you become familiar with biology concepts AND practice your reading skills (which is helpful for all sections of the MCAT, but especially CARS). Try reading books written by physicians, which often discuss clinical cases and include mentions of physiology concepts, as these are often quite interesting to read and will also help you do well on the whole MCAT (including the biology section).

Appendix: What Biology Concepts Are on the MCAT?

MCAT section 1: Chemical and Physical Foundations of Biological Systems (CPBS) - first-semester biochemistry 25%, introductory biology 5%

MCAT section 3: Biological and Biochemical Foundations of Living Systems (BBLS) – 65% introductory biology, 25% first-semester biochemistry

MCAT section 4: Psychological, Social, and Biological Foundations of Behavior (PSBB) – 5% introductory biology


1. How much biology is on the MCAT?

Biology is prominently featured in the MCAT. For example, biology questions compose 90% of the second section of the MCAT, Biological and Biochemical Foundations of Living Systems. You may expect to see a biology-related question in most sections of the MCAT, perhaps with the exception of CARS. If you want to see a complete breakdown of the MCAT sections, read our “How long is the MCAT?” blog.

2. What kind of coursework should I pursue in my undergrad to get ready for MCAT biology?

Most medical school prerequisites do cover the MCAT biology content, but some do not. If you think that taking advanced undergrad biology courses will help you better prepare for the exam, you should research your school’s directory of courses and see which classes will cover topics you haven’t had the chance to learn. Advanced biology courses are not required, but they may help you.

3. How important is my knowledge of biology for the MCAT?

You must have a solid knowledge of biology for the MCAT. Notice that three out of the four MCAT sections include some biology-related concepts that you need to know for the exam. There is definitely a correlation between a solid knowledge of biology and a good MCAT score.

4. I am having trouble with biology-related passages. How can I improve my reading and comprehension of the graphs, charts, and images within the passages?

You can strengthen your reading and comprehension of experiment-based passages that often include images and graphs by joining a research lab. Getting involved in research will also expand your scientific knowledge and bolster your med school applications. When you start looking for research positions, don’t forget to accompany your job application or CV with a strong research assistant cover letter. Another way to increase your reading and comprehension of biology passages is to read scientific journals. Get used to reading an article each week and analyzing its graphs and figures. You can even try explaining the graphs and figures to others – if they understand your explanation, you are on track with your MCAT biology prep!

5. I do well with other MCAT concepts and disciplines, but biology and biochemistry are my weakness. Does it really matter?

Some medical schools pay attention to only one MCAT section during application review. For example, the McMaster medical school in Ontario, Canada only considers your CARS score during the review. However, most schools look at each section separately, and then your sum score. So, it's important to do well in all four sections, because most schools do look at the score of each section and your cumulative score. Consistency demonstrates your competence in all scientific and social science disciplines. Remember each section makes up 25% of your total MCAT score!

6. There is so much biology on the exam! How can I review all this content?

Your success will depend on your diligence and time management. Remember, ideally, you will have about 6 months to review all the MCAT disciplines. Be sure to create a thorough study schedule that includes the content you need to cover and the study strategies you will use. Additionally, don’t be afraid of changing the schedule as you begin your MCAT prep. It’s normal to rearrange and improve your study plan as you work through the concepts. If you have less than 6 months, you will need to arrange your study schedule to meet your needs and focus on content areas that need your attention, e.g. if you struggle with CARS, focus on CARS prep, if you struggle with physics, practice with physics equations and concepts, etc.  

7. When should I take the MCAT?

Before you are ready to take your MCAT, take as many diagnostic tests as possible. Firstly, pay attention to whether you are improving and keep studying if you are. Remember, you are not simply trying to get a “good enough” score – you are trying to get the highest score possible! If you plateau and are happy with the score you are getting (around 90%), then you may take the test.

8. Do I have to take biology courses in university to do well?

This is recommended, as there is a lot of material to be covered. However, you must judge your own strengths. Perhaps you are very strong in biology and can review the material using textbooks on your own time. The bottom line: Leave enough time to cover the vast amount of biology material that will be on the MCAT.

9. How come the biology section does not have more anatomy and physiology?

Anatomy and physiology are covered extensively DURING medical school. Before medical school, programs want to know you have the basic science knowledge and critical thinking skills to excel at learning anatomy, physiology, and clinical medicine, so while some of this knowledge is needed for the MCAT, other concepts in biology are also important.

10. Why is active learning a good way to learn?

Active learning involves engaging with the material, whereas more passive learning involves things like listening to lectures or rote memorization. Active learning will cement concepts in your brain more than passive learning by itself can (although lectures, reading, and memorization are often required before active learning can occur). So, try drawing out concepts yourself, or teaching another student a difficult biology topic. These types of active learning will show that you have really understood the material and they are a lot more fun also!

To your success,

Your friends at BeMo

BeMo Academic Consulting

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