Skip to content

Chapters

This textbook is organized into 20 chapters covering all 380 AP Biology concepts, aligned to the 8 College Board AP Biology units. Chapters are ordered so that every prerequisite concept appears before the chapters that depend on it.

Chapter Overview

Unit 1 — Chemistry of Life

  1. Scientific Foundations and Atomic Chemistry — Introduces the scientific method, experimental design, and statistical reasoning, then lays the atomic and chemical bonding foundations underlying all of biology.
  2. Water, pH, and Organic Chemistry — Explores the life-enabling properties of water, acid-base chemistry and buffers, and the organic functional groups that form the backbone of all biomolecules.
  3. Biological Macromolecules — Examines the four classes of biological macromolecules — carbohydrates, lipids, proteins, and nucleic acids — including their monomers, bonds, structures, and functions.

Unit 2 — Cell Structure and Function

  1. Cell Organization and Organelles — Introduces cell theory, compares prokaryotic and eukaryotic cells, and surveys the organelles and cytoskeletal elements that define eukaryotic cell architecture.
  2. Cell Membranes and Transport — Analyzes the fluid mosaic model of membrane structure and all mechanisms — passive and active — by which substances move across cell membranes.

Unit 3 — Cellular Energetics

  1. Thermodynamics and Enzyme Kinetics — Establishes the thermodynamic principles governing biological reactions and examines enzyme structure, catalytic mechanism, and regulation.
  2. Photosynthesis — Traces the two stages of photosynthesis — the light-dependent reactions and the Calvin cycle — and compares C3, C4, and CAM photosynthetic strategies.
  3. Cellular Respiration and Fermentation — Follows the complete oxidation of glucose through glycolysis, the Krebs cycle, and oxidative phosphorylation, and examines anaerobic fermentation pathways.

Unit 4 — Cell Communication and the Cell Cycle

  1. Cell Signaling and Feedback — Describes how cells receive, transduce, and respond to extracellular signals through receptor types, second-messenger cascades, feedback loops, and apoptosis.
  2. The Cell Cycle, Mitosis, and Cancer — Examines the stages of the eukaryotic cell cycle and mitosis, and explains how disruption of checkpoints and regulatory proteins drives cancer.

Unit 5 — Heredity

  1. Meiosis and Mendelian Genetics — Covers the mechanics of meiosis that generate genetically unique gametes, then applies Mendel's laws to predict inheritance outcomes in monohybrid and dihybrid crosses.
  2. Non-Mendelian Inheritance and Chromosomal Genetics — Extends Mendelian principles to incomplete dominance, codominance, polygenic traits, sex-linked inheritance, and chromosomal abnormalities analyzed through pedigrees.

Unit 6 — Gene Expression and Regulation

  1. The Central Dogma: DNA Replication and Protein Synthesis — Traces the central dogma from DNA replication through transcription and RNA processing to ribosomal translation.
  2. Mutations, Gene Regulation, and Biotechnology — Examines how mutations alter gene products, how prokaryotic and eukaryotic cells regulate gene expression, and introduces modern biotechnology tools including PCR, CRISPR, and genomics.

Unit 7 — Natural Selection and Evolution

  1. Evidence for Evolution and Mechanisms of Change — Reviews Darwin's theory and the fossil, anatomical, and molecular evidence supporting it, then examines natural selection and other mechanisms of evolutionary change.
  2. Population Genetics and Hardy-Weinberg Equilibrium — Applies population genetics to quantify allele frequencies, model Hardy-Weinberg equilibrium, and analyze how drift, gene flow, mutation, and selection alter population variation.
  3. Speciation, Phylogenetics, and Macroevolution — Explains how reproductive isolation leads to speciation, introduces cladistic methods for reconstructing evolutionary history, and surveys large-scale patterns in evolution.

Unit 8 — Ecology

  1. Population Ecology and Life History — Models how populations grow, what limits their size, and how natural selection shapes life history trade-offs between reproduction and survival.
  2. Community Ecology and Species Interactions — Analyzes the full range of interspecific interactions — predation, competition, mutualism, parasitism — and the processes of ecological succession that shape community structure.
  3. Ecosystem Ecology, Biogeochemical Cycles, and Conservation — Traces energy flow and nutrient cycling through ecosystems, surveys major biomes, and evaluates conservation strategies for protecting biodiversity in a changing world.

How to Use This Textbook

Work through chapters in order — every chapter is written with the assumption that you have completed all preceding chapters. Within each chapter, use the interactive MicroSim diagrams in Explore mode to build understanding, then switch to Quiz mode to test yourself before the chapter quiz.

Each chapter includes a Concepts Covered list that maps directly to the AP Biology learning graph. If you are strong in certain areas, you can use the learning graph viewer to identify which chapters to focus on.

Note: All 380 concepts are covered exactly once across these 20 chapters. Chapter dependencies are fully respected: no concept appears before all its prerequisites have been introduced.