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AP Biology

How living things work, from molecules to ecosystems

AP Biology asks you to explain how living systems work and to reason from evidence: read an experiment, predict what a change will do, and justify the claim with data. Each lesson asks you to predict before it explains, and every wrong answer says which mistake it comes from. The lessons are being written one unit at a time.

AP Biology Exam Monday, May 3, 2027

Start Lesson 1.1 Structure of Water and Hydrogen Bonding

Units

Eight units, in the order College Board's course framework sets them. Each unit's share of the multiple-choice section is printed beside it, as College Board publishes it.

  1. Unit 1 Chemistry of Life 8–11% of the multiple-choice section · 7 topics
    1. 1.1Structure of Water and Hydrogen Bonding
    2. 1.2Elements of Life
    3. 1.3Introduction to Macromolecules
    4. 1.4Carbohydrates
    5. 1.5Lipids
    6. 1.6Nucleic Acids
    7. 1.7Proteins

    Unit 1 overviewUnit 1 check

  2. Unit 2 Cells 10–13% of the multiple-choice section · 10 topics
    1. 2.1Cell Structure and Function
    2. 2.2Cell Size
    3. 2.3Plasma Membrane
    4. 2.4Membrane Permeability
    5. 2.5Membrane Transport
    6. 2.6Facilitated Diffusion
    7. 2.7Tonicity and Osmoregulation
    8. 2.8Mechanisms of Transport
    9. 2.9Cell Compartmentalization
    10. 2.10Origins of Cell Compartmentalization

    Unit 2 overviewUnit 2 check

  3. Unit 3 Cellular Energetics 12–16% of the multiple-choice section · 5 topics
    1. 3.1Enzymes
    2. 3.2Environmental Impacts on Enzyme Function
    3. 3.3Cellular Energy
    4. 3.4Photosynthesis
    5. 3.5Cellular Respiration

    Unit 3 overviewUnit 3 check

  4. Unit 4 Cell Communication and Cell Cycle 10–15% of the multiple-choice section · 6 topics
    1. 4.1Cell Communication
    2. 4.2Introduction to Signal Transduction
    3. 4.3Signal Transduction Pathways
    4. 4.4Feedback
    5. 4.5Cell Cycle
    6. 4.6Regulation of Cell Cycle

    Unit 4 overviewUnit 4 check

  5. Unit 5 Heredity 8–11% of the multiple-choice section · 5 topics
    1. 5.1Meiosis
    2. 5.2Meiosis and Genetic Diversity
    3. 5.3Mendelian Genetics
    4. 5.4Non-Mendelian Genetics
    5. 5.5Environmental Effects on Phenotype

    Unit 5 overviewUnit 5 check

  6. Unit 6 Gene Expression and Regulation 12–16% of the multiple-choice section · 8 topics
    1. 6.1DNA and RNA Structure
    2. 6.2DNA Replication
    3. 6.3Transcription and RNA Processing
    4. 6.4Translation
    5. 6.5Regulation of Gene Expression
    6. 6.6Gene Expression and Cell Specialization
    7. 6.7Mutations
    8. 6.8Biotechnology

    Unit 6 overviewUnit 6 check

  7. Unit 7 Natural Selection 13–20% of the multiple-choice section · 12 topics
    1. 7.1Introduction to Natural Selection
    2. 7.2Natural Selection
    3. 7.3Artificial Selection
    4. 7.4Population Genetics
    5. 7.5Hardy–Weinberg Equilibrium
    6. 7.6Evidence of Evolution
    7. 7.7Common Ancestry
    8. 7.8Continuing Evolution
    9. 7.9Phylogeny
    10. 7.10Speciation
    11. 7.11Variations in Populations
    12. 7.12Origins of Life on Earth

    Unit 7 overviewUnit 7 check

  8. Unit 8 Ecology 10–15% of the multiple-choice section · 7 topics
    1. 8.1Responses to the Environment
    2. 8.2Energy Flow Through Ecosystems
    3. 8.3Population Ecology
    4. 8.4Effect of Density on Populations
    5. 8.5Community Ecology
    6. 8.6Biodiversity
    7. 8.7Disruptions in Ecosystems

    Unit 8 overviewUnit 8 check

Labs

Labs for this course are being built.

The exam

The exam is hybrid digital: you answer the multiple-choice questions in the Bluebook app and handwrite your free-response answers in a paper booklet. A four-function, scientific, or graphing calculator is allowed on both sections of the exam.

Exam format and practice