MCAT Sections: What's on the MCAT?

Textbook with a stethoscope

ktasimarr / Getty Images

The Medical College Admission Test (MCAT) is a 7.5 hour exam required for admission to U.S. medical schools. The MCAT divided into the following four sections: Biological and Biochemical Foundations of Living Systems; Chemical and Physical Foundations of Biological Systems; Psychological, Social, and Biological Foundations of Behavior; and Critical Analysis and Reasoning Skills (CARS).

Overview of MCAT Sections
Section Length Time Topics Covered
Biological and Biochemical Foundations of Living Systems 59 multiple-choice questions 95 minutes Introductory biology (65%), first-semester biochemistry (25%), general chemistry (5%), organic chemistry (5%) 
Chemical and Physical Foundations of Biological Systems 59 multiple-choice questions 95 minutes General chemistry (30%), first-semester biochemistry (25%), introductory physics (25%), organic chemistry (15%), introductory biology (5%) 
Psychological, Social, and Biological Foundations of Behavior 59 multiple-choice questions 95 minutes Introductory psychology (65%), introductory sociology (30%), introductory biology (5%) 
Critical Analysis and Reasoning Skills 53 multiple-choice questions 90 minutes Reasoning beyond the text (40%), reasoning within the text (30%), foundations of comprehension (30%)

Each of the three science-based sections consist of 59 questions: 15 stand-alone knowledge questions and 44 passage-based questions. The fourth section, CARS, includes all passage-based questions. Calculators are not permitted, so basic math knowledge is required (particularly logarithmic and exponential functions, square roots, basic trigonometry, and unit conversions).

In addition to content knowledge, the MCAT tests scientific reasoning and problem solving, research design and execution, and data-based and statistical reasoning. To succeed, you must have deep knowledge of scientific concepts and be able to apply your knowledge in a multidisciplinary fashion.

Biological and Biochemical Foundations of Living Systems

The Biological and Biochemical Foundations of Living Systems (Bio/Biochem) section covers basic life processes such as energy production, growth, and reproduction. This section requires detailed knowledge of cell structure, cell function, and how organ systems interact.

Most of the material in this section comes from introductory biological sciences (65%) and biochemistry (25%). A small portion of the section is devoted to introductory chemistry (5%) and organic chemistry (5%). Advanced coursework in cellular and molecular biology, anatomy and physiology, and genetics will be useful for this section, but they aren’t necessary.

The Bio/Biochem section covers three foundational concepts: (1) protein structure, protein function, genetics, bioenergetics, and metabolism; (2) molecular and cellular assemblies, prokaryotes and viruses, and cell division processes; and (3) nervous and endocrine systems, major organ systems, skin, and muscle systems. However, simply memorizing the main scientific principles associated with these concepts is not enough to ace the Bio/Biochem section.  Be prepared to apply your knowledge to novel situations, interpret data, and analyze research. 

A periodic table is provided for this section, though you’ll probably use it more frequently in the next section (Chem/Phys).

Chemical and Physical Foundations of Biological Systems

The Chemical and Physical Foundations of Biological Systems (Chem/Phys) section covers chemistry and physics. Chem/Phys sometimes inspires fear in test takers, especially pre-med biology majors whose chemistry and physics knowledge is limited to a few intro courses. If that sounds like you, rest assured that the Chem/Phys section focuses on applications of chemistry and physics (i.e., how chemistry and physics apply to biological systems and processes that occur in the human body).

In this section, test takers can expect to encounter concepts from general introductory chemistry (30%), organic chemistry (15%), biochemistry (25%), and physics (25%), as well as a small amount of basic biology (5%).

The Chem/Phys section focuses on two foundational concepts: (1) how living organisms respond to their environment (motion, forces, energy, fluid movement, electrochemistry and electronics, light and sound interactions with matter, atomic structure and behavior) and (2) chemical interactions with living systems (water and solution chemistry, molecular/biomolecular properties and interactions, molecular separation/purification, thermodynamics and kinetics).

A basic periodic table is provided for this section. The table does not include periodic trends or the full names of elements, so make sure to review and memorize trends and abbreviations.

Psychological, Social, and Biological Foundations of Behavior

The Psychological, Social, and Biological Foundations of Behavior (Psych/Soc) section is the newest addition to the MCAT. Psych/Soc covers the following concepts within introductory psychology (65%), introductory sociology (30%), and introductory biology (5%): brain anatomy, brain function, behavior, emotion, self and social perceptions, social differences, social stratification, learning, and memory as they relate to psychology and sociology. The section also tests your ability to analyze research methodologies and interpret statistical data.

Although not all medical schools require formal undergraduate coursework in the social sciences, incoming medical students are expected to understand the interrelationship between psychology, society, and health. Some students underestimate the challenges this section presents, so make sure to allot adequate time for studying. Remember, knowing psychological terms and principles is not enough to succeed on this section. You should be able to apply your knowledge to interpret data and solve complex problems.

Critical Analysis and Reasoning Skills

The Critical Analysis and Reasoning Skills (CARS) section tests your ability to use logic and reasoning to analyze arguments and make deductions. Unlike the other sections, CARS does not require a substantial base of existing knowledge. Instead, this section requires a strong set of problem-solving skills. CARS is also five minutes and six questions shorter than the other sections.

The passage-based questions cover three main skills: written comprehension (30%), reasoning within the text (30%), and reasoning outside the text (40%). Half of the passage topics are humanities-focused, while the other half come from the social sciences. The best way to prepare for the CARS section is to practice with as many sample passages as possible.