What’s tested on the MCAT: Biology

The Biological and Biochemical Foundations of Living Systems section of the MCAT, often called the MCAT Biology or MCAT Bio/Biochem section for short, requires you to solve problems based on knowledge of biological and biochemical concepts combined with scientific inquiry and reasoning skills. The content on this section of the test also includes some general chemistry and organic chemistry.
However, you should keep in mind that the MCAT requires more than just an understanding of science content. The MCAT is first and foremost a test of critical reasoning skills. Knowing how to use biology and biochemistry information to interpret and solve more difficult problems is the key to a great MCAT score. However, without the foundational content, it is just as difficult to do well on the MCAT. As the official MCAT® prep of the American Medical Student Association, here are Kaplan’s recommendations for what to know for the biology section of the MCAT.

The undergraduate courses that are reflected in the Bio/Biochem section of the MCAT are introductory Biology (65%), introductory General Chemistry (5%), introductory Organic Chemistry (5%),  and first-semester Biochemistry (25%). Additional biology classes such as Cell Biology, Genetics, Anatomy and Physiology, or Microbiology can be helpful, but aren’t required.
In order to study effectively for the MCAT Biological and Biochemical Foundations of Living Systems section, you should thoroughly understanding these biology and biochemistry topics:

Biology subjects to study for the MCAT:
The Cell	Reproduction	Embryogenesis and Development
The Nervous System	The Endocrine System	The Respiratory System
The Cardiovascular System	The Immune System	The Digestive System
The Excretory System	The Musculoskeletal System	Genetics and Evolution

Biochemistry subjects to study for the MCAT:
Amino Acids, Peptides and Proteins	Enzymes	Nonenzymatic proteins
Carbohydrate structure	Carbohydrate metabolism	Lipids and lipid metabolism
DNA and RNA	Biological Membranes	Regulation of metabolism

The critical reasoning skills required for the MCAT have been defined by the AAMC as Scientific Reasoning and Inquiry Skills, or SIRS. These skills are tested in all three of the science sections of the MCAT (Chemical and Physical Foundations of Biological Systems, Biological and Biochemical Foundations of Living Systems, and Psychological, Social and Biological Foundations of Behavior). These four skills are:

You can learn more about these four Scientific Reasoning and Inquiry skills here.


The MCAT will present you with 10 passages on biology and biochemistry topics, and ask 4-7 questions about each passage. The questions will address the four skills listed, although not every passage will require you to use each skill. You will also be presented with 15 discrete questions that are not associated with passages. These will also be designed to test both your science knowledge and application of that knowledge based on these four skills. You can find more details on what you need to know about the overall structure of the MCAT here.
The biology/biochem section of the MCAT is scored on a curved scale of 118-132, with the median score of all test takers set at 125. There is no specific number of right or wrong questions that corresponds to a given scaled score; instead, each test administration is curved according to its level of difficulty and the performance of the test-takers on that day. The score for this section of the test is combined with the other three sections to give an overall score ranging from 472 to 528.
You should also be familiar with the test day schedule. The Biology/Biochem section of the MCAT is the third section to be tested, and follows a thirty-minute lunch break.

Biological and Biochemical Foundations of Living Systems section
Length	95 minutes
Format	59 questions
	10 passages
	44 passage-based questions
	15 discrete (non-passage based) questions
Score	Between 118 and 132
Topics tested	Biochemistry: 25%
	Biology: 65%
	General Chemistry: 5%
	Organic Chemistry: 5%

The AAMC has described the topics within the Biological and Biochemical Foundations of Living Systems section of the MCAT. These topics are subdivided into three Foundational Concepts, each of which has several sub-categories.
To learn about Foundational Topics 4-5, covered in the Chem/Physics section of the test, click here, and Foundational Topics 6-10, covered in the Psychological, Social, and Biological Foundations of Behavior Section, click here.
You can also visit the AAMC site to learn more about the MCAT Blueprint.
The Foundational Topics for the Biological and Biochemical Foundations of Living Systems are:
1) Structure and function of biomolecules. This is further subdivided into four categories:

1A) Structure and function of proteins and their constituent amino acids

1B) Transmission of genetic information from the gene to the protein

1C) Transmission of heritable information from generation to generation and the processes that increase genetic diversity

1D) Principles of bioenergetics and fuel molecule metabolism

2) Interaction of highly-organized assemblies of molecules, cells and organs to carry out the functions of living organisms. This is further subdivided into three categories:

2A) Assemblies of molecules, cells and groups of cells within single cellular and multcellular organisms

2B) The structure, growth, physiology and genetics of prokaryotes and viruses

2C) Processes of cell division, differentiation and specialization

3) Integrated functioning of complex systems of tissues and organs to sense internal and external environments of multicellular organism and to maintain a stable internal environment within an ever changing external environment. This is further subdivided into two subcategories:

3A) Structure and function of the nervous and endocrine systems and ways in which these systems coordinate organ systems.

3B) Structure and integrative function of the main organ systems.

The most important factor you should consider about the Bio/Biochem section of the MCAT is how well prepared you are for both the content and the critical reasoning required. To learn more about how to prepare for the test, click here.