AP Biology study guide
AP Biology · Work through your exam, one topic at a time.
AP Biology is a College Board Advanced Placement course and exam intended to mirror a two-semester college introductory biology sequence for biology majors; the source recommends prior high school coursework in biology and chemistry. The course spans eight units, from the chemistry of life and cell structure through cellular energetics, cell communication and the cell cycle, heredity, gene expression and regulation, natural selection, and ecology, with published exam-score ranges of roughly 8% to 20% per unit. The AP Biology study guide has 8 sections and about 2,099 words.
01Chemistry of Life
Life is built from a small set of elements (C, H, O, N, P, S) arranged into four macromolecule classes: carbohydrates, lipids, proteins, and nucleic acids. Each class is a polymer (or, for lipids, an assembled structure) of monomers joined by dehydration synthesis and broken by hydrolysis .
329 words, about 2 min02Cells
Cells are the basic unit of life, bounded by a selectively permeable membrane described by the fluid mosaic model. The phospholipid bilayer creates a hydrophobic core; proteins, cholesterol, and glycoproteins modulate transport and signaling.
296 words, about 1 min03Cellular Energetics
Cells couple exergonic (energy-releasing) reactions to endergonic (energy-requiring) ones via ATP . Enzymes lower activation energy without changing the overall free-energy change; they are not consumed and do not alter equilibrium.
275 words, about 1 min04Cell Communication and Cell Cycle
Cells communicate through signal transduction : a signal (ligand) binds a receptor, triggering a transduction cascade that produces a cellular response. Receptors include G protein-coupled receptors, receptor tyrosine kinases, and intracellular receptors (for lipid-soluble signals like steroids).
247 words, about 1 min05Heredity
Mendelian genetics rests on segregation and independent assortment of alleles. Know how to set up Punnett squares and predict genotype and phenotype ratios.
241 words, about 1 min06Gene Expression and Regulation
The central dogma flows DNA → RNA → protein. Transcription (nucleus in eukaryotes) makes mRNA; translation (ribosome) builds protein from codons.
247 words, about 1 min07Natural Selection
Evolution is change in allele frequencies in a population over time. Natural selection acts on heritable variation; individuals with favorable traits reproduce more, shifting allele frequencies.
225 words, about 1 min08Ecology
Ecology studies interactions between organisms and their environment. Energy flows through ecosystems in one direction, while matter cycles .
239 words, about 1 min