AP Biology Concept Taxonomy
Twelve categories organize the 375 AP Biology concepts into coherent thematic groups for visualization and navigation. Each category is assigned a short TaxonomyID (uppercase, 3-5 letters) used in the learning graph CSV and JSON.
1. Scientific Foundations (FOUND)
TaxonomyID: FOUND
Concepts relating to the nature of science, experimental design, statistical reasoning, and quantitative data skills. These underpin all other units.
Includes: Scientific Method, Hypothesis Testing, Controlled Experiments, Independent and Dependent Variables, Chi-Square Statistical Test, Standard Deviation, Data Interpretation, Graph Construction and Analysis.
2. Chemistry of Life (CHEM)
TaxonomyID: CHEM
Atomic and molecular concepts, chemical bonding, water chemistry, acid-base chemistry, and organic chemistry that form the chemical foundation of biology.
Includes: Atomic Structure, Elements of Life, Chemical Bonds, Ionic Bonds, Covalent Bonds, Hydrogen Bonds, Van der Waals Forces, Water Polarity, Cohesion and Adhesion, Surface Tension, Specific Heat Capacity, Water as Universal Solvent, Hydrophilic and Hydrophobic, Acid-Base Chemistry, pH Scale, Buffers, Organic Chemistry Basics, Functional Groups, Polymers and Monomers, Condensation Reactions, Hydrolysis Reactions.
3. Macromolecules (MACRO)
TaxonomyID: MACRO
The four major classes of biological macromolecules — carbohydrates, lipids, proteins, and nucleic acids — including their monomers, structures, and functions.
Includes: Carbohydrates, Monosaccharides, Disaccharides, Polysaccharides, Glycosidic Bonds, Lipids, Fatty Acids, Saturated and Unsaturated Fats, Triglycerides, Phospholipids, Sterols and Cholesterol, Proteins, Amino Acids, Peptide Bonds, Primary Protein Structure, Secondary Protein Structure, Tertiary Protein Structure, Quaternary Protein Structure, Protein Denaturation, Nucleic Acids, Nucleotides, DNA Structure, RNA Structure.
4. Cell Biology (CELL)
TaxonomyID: CELL
Cell theory, prokaryotic and eukaryotic cell organization, organelles, cell membranes, membrane transport, and cellular infrastructure.
Includes: Cell Theory, Prokaryotic Cells, Eukaryotic Cells, Cell Size and Surface Area Ratio, Plasma Membrane, Fluid Mosaic Model, Phospholipid Bilayer, Membrane Proteins, Cholesterol in Membranes, Selective Permeability, Passive Transport, Diffusion, Osmosis, Water Potential, Turgor Pressure, Facilitated Diffusion, Active Transport, Sodium-Potassium Pump, Endocytosis, Exocytosis, Phagocytosis, Pinocytosis, Nucleus, Nuclear Envelope, Nucleolus, Endoplasmic Reticulum, Rough ER, Smooth ER, Golgi Apparatus, Lysosomes, Vacuoles, Mitochondria, Chloroplasts, Peroxisomes, Cytoskeleton, Microfilaments, Microtubules, Intermediate Filaments, Cilia and Flagella, Cell Wall, Plasmodesmata, Extracellular Matrix, Cell Junctions.
5. Cellular Energetics (ENRG)
TaxonomyID: ENRG
Thermodynamics, enzyme kinetics, photosynthesis, and cellular respiration — all processes involving energy transformation in living systems.
Includes: Thermodynamics, First Law of Thermodynamics, Second Law of Thermodynamics, Entropy, Free Energy (Gibbs), Exergonic Reactions, Endergonic Reactions, ATP Structure, ATP Hydrolysis, Coupled Reactions, Redox Reactions, Enzymes, Active Site, Enzyme-Substrate Complex, Activation Energy, Transition State, Induced Fit Model, Enzyme Cofactors and Coenzymes, Competitive Inhibition, Noncompetitive Inhibition, Allosteric Regulation, Feedback Inhibition, Temperature and Enzyme Activity, pH and Enzyme Activity, Photosynthesis Overview, Chlorophyll and Pigments, Absorption Spectrum, Photosystems I and II, Light-Dependent Reactions, Photolysis of Water, Electron Transport Chain (Chloroplast), ATP Synthase, Proton Gradient, Calvin Cycle, Carbon Fixation, RuBisCO, G3P and Sugar Production, C3 Plants, C4 Plants, CAM Plants, Photorespiration, Cellular Respiration Overview, Glycolysis, Substrate-Level Phosphorylation, Pyruvate Oxidation, Acetyl-CoA, Krebs Cycle, Electron Transport Chain (Mitochond.), Oxidative Phosphorylation, Chemiosmosis, NADH and FADH2, ATP Yield of Respiration, Fermentation, Lactic Acid Fermentation, Alcoholic Fermentation.
6. Cell Communication and Division (COMM)
TaxonomyID: COMM
Cell signaling pathways, feedback mechanisms, apoptosis, the cell cycle, mitosis, and the regulation of cell division including cancer biology.
Includes: Cell Signaling Overview, Signal Transduction, Ligand-Receptor Binding, Cell Surface Receptors, G Protein-Coupled Receptors, Receptor Tyrosine Kinases, Intracellular Receptors, Second Messengers, cAMP Signaling, Phosphorylation Cascades, Signal Amplification, Negative Feedback Loops, Positive Feedback Loops, Apoptosis, Cell Cycle Overview, G1 Phase, S Phase, G2 Phase, Mitosis, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis, Cell Cycle Checkpoints, Cyclins and CDKs, Proto-Oncogenes, Tumor Suppressor Genes, Cancer Biology, Contact Inhibition.
7. Heredity and Genetics (GENET)
TaxonomyID: GENET
Meiosis, Mendelian inheritance, extensions of Mendelian genetics, sex-linked traits, chromosomal genetics, and statistical analysis of inheritance patterns.
Includes: Meiosis Overview, Meiosis I, Meiosis II, Synapsis and Tetrad Formation, Crossing Over, Chiasmata, Genetic Recombination, Haploid and Diploid Cells, Gametes, Fertilization, Chromosomal Theory of Inheritance, Mendel's Law of Segregation, Mendel's Law of Indep. Assortment, Dominant and Recessive Alleles, Genotype and Phenotype, Homozygous and Heterozygous, Monohybrid Crosses, Dihybrid Crosses, Punnett Squares, Test Crosses, Incomplete Dominance, Codominance, Multiple Alleles, Sex Determination, Sex-Linked Traits, X-Linked Inheritance, Polygenic Inheritance, Epistasis, Pleiotropy, Genetic Linkage, Recombination Frequency, Chromosomal Abnormalities, Nondisjunction, Aneuploidy, Pedigree Analysis.
8. Molecular Biology (MOLBIO)
TaxonomyID: MOLBIO
DNA replication, transcription, RNA processing, translation, gene mutations, and the central dogma of molecular biology.
Includes: DNA Double Helix, Base Pairing Rules, DNA Replication, DNA Polymerase, Semiconservative Replication, Leading and Lagging Strands, Okazaki Fragments, DNA Proofreading and Repair, Telomeres, Transcription Overview, RNA Polymerase, Promoter Regions, Transcription Termination, mRNA Processing, 5-Prime Cap and Poly-A Tail, RNA Splicing, Introns and Exons, Alternative Splicing, Translation Overview, Ribosomes, Codons and Anticodons, tRNA Structure, Aminoacyl-tRNA Synthetases, Start and Stop Codons, Genetic Code, Polysomes, Point Mutations, Frameshift Mutations, Silent Mutations, Missense Mutations, Nonsense Mutations, Mutagens and DNA Damage.
9. Gene Regulation and Biotechnology (BIOTECH)
TaxonomyID: BIOTECH
Prokaryotic and eukaryotic gene regulation, epigenetics, and biotechnology tools including PCR, CRISPR, gel electrophoresis, DNA sequencing, and genomics.
Includes: Gene Regulation (Prokaryotes), Operons, Lac Operon, Trp Operon, Gene Regulation (Eukaryotes), Transcription Factors, Enhancers and Silencers, Epigenetic Regulation, DNA Methylation, Histone Modification, Chromatin Remodeling, MicroRNAs, Biotechnology Overview, Restriction Enzymes, Gel Electrophoresis, PCR, DNA Cloning, Recombinant DNA Technology, CRISPR-Cas9, Gene Therapy Concepts, DNA Sequencing, Genomics Overview, Bioinformatics Basics.
10. Evolution (EVOL)
TaxonomyID: EVOL
Evolutionary mechanisms, population genetics, natural selection, speciation, phylogenetics, macroevolution, and evidence for evolution.
Includes: History of Evolutionary Thought, Darwin's Observations, Natural Selection, Variation in Populations, Heritability, Relative Fitness, Artificial Selection, Fossil Record Evidence, Relative and Absolute Dating, Comparative Anatomy, Homologous Structures, Analogous Structures, Vestigial Structures, Comparative Embryology, Molecular Evidence for Evolution, Biogeography, Population Genetics, Allele Frequency, Hardy-Weinberg Equilibrium, Hardy-Weinberg Assumptions, Genetic Drift, Founder Effect, Bottleneck Effect, Gene Flow, Mutation and Evolution, Sexual Selection, Stabilizing Selection, Directional Selection, Disruptive Selection, Biological Species Concept, Speciation Overview, Reproductive Isolation, Prezygotic Barriers, Postzygotic Barriers, Allopatric Speciation, Sympatric Speciation, Adaptive Radiation, Convergent Evolution, Coevolution, Phylogenetics, Cladistics, Cladograms, Shared Derived Characters, Molecular Clocks, Macroevolution, Mass Extinctions, Endosymbiotic Theory, Origin of Eukaryotes, Three Domains of Life.
11. Population and Community Ecology (POPECO)
TaxonomyID: POPECO
Population dynamics (growth models, limiting factors, life history), community interactions (predation, competition, mutualism), succession, and keystone species.
Includes: Ecology Overview, Levels of Ecological Organization, Abiotic and Biotic Factors, Population Ecology, Population Density, Dispersion Patterns, Exponential Population Growth, Logistic Population Growth, Carrying Capacity, Limiting Factors, Density-Dependent Regulation, Density-Independent Factors, Survivorship Curves, Life History Strategies, r-Selection and K-Selection, Community Ecology, Interspecific Interactions, Predation, Herbivory, Competition, Competitive Exclusion Principle, Resource Partitioning, Ecological Niches, Mutualism, Commensalism, Parasitism, Keystone Species, Trophic Cascades, Ecological Succession, Primary Succession, Secondary Succession, Climax Community, Island Biogeography.
12. Ecosystem and Global Ecology (ECOSYS)
TaxonomyID: ECOSYS
Ecosystem energy flow, biogeochemical cycles, biomes, biodiversity, conservation biology, climate change, and human impact on ecosystems.
Includes: Ecosystem Ecology, Trophic Levels, Food Chains and Food Webs, Energy Flow in Ecosystems, Ten Percent Energy Rule, Primary Productivity, Net Primary Productivity, Biogeochemical Cycles, Carbon Cycle, Nitrogen Cycle, Phosphorus Cycle, Water Cycle, Nitrogen Fixation, Biomes Overview, Terrestrial Biomes, Aquatic Biomes, Biodiversity, Species Richness and Evenness, Habitat Fragmentation, Invasive Species, Climate Change and Ecology, Conservation Biology, Ecological Footprint.