AP Biology · All 8 Units

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AP Biology

Spaced repetition flashcards, daily games, and 1,500+ key terms — covering all 8 AP Biology units. Free, forever.

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1,500+
AP Biology key terms
8
AP units covered
4
Revision games
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All 8 AP Biology Units

Cramly covers every topic from the AP Biology curriculum framework, with flashcards organized by unit.

Unit 1

Chemistry of Life

Water and its properties, biological macromolecules (carbohydrates, lipids, proteins, nucleic acids), condensation and hydrolysis, and the properties of carbon.

Unit 2

Cell Structure and Function

Prokaryotic and eukaryotic cell structure, organelles, the fluid mosaic model, cell transport (diffusion, osmosis, active transport), and cell communication.

Unit 3

Cellular Energetics

Enzymes and activation energy, photosynthesis (light reactions and Calvin cycle), cellular respiration (glycolysis, Krebs cycle, oxidative phosphorylation), and fermentation.

Unit 4

Cell Communication and Cell Cycle

Signal transduction pathways, feedback mechanisms, the cell cycle, mitosis, meiosis, cancer and apoptosis, and mechanisms of cell communication.

Unit 5

Heredity

Mendelian genetics, Punnett grids, sex linkage, codominance, incomplete dominance, dihybrid crosses, non-disjunction, and chromosomal abnormalities.

Unit 6

Gene Expression and Regulation

DNA replication, transcription, translation, mutations, epigenetics, gene regulation, CRISPR, operons, and biotechnology techniques (PCR, gel electrophoresis).

Unit 7

Natural Selection

Evolution and natural selection, population genetics, Hardy-Weinberg equilibrium, speciation, phylogenetics, and evidence for evolution.

Unit 8

Ecology

Population ecology, community interactions, energy flow, biogeochemical cycles, biodiversity, climate change, and human impacts on ecosystems.

Key vocabulary

Essential AP Biology Terms

AP Biology free response questions reward precise terminology. Here's a sample of terms covered in Cramly.

Acetyl-CoA
Active Transport
Allele Frequency
Anaphase
Anticodon
Apoptosis
ATP Synthase
Calvin Cycle
Carrying Capacity
Chemiosmosis
Chitin
Chromatid
Cladogram
Codominance
Commensalism
Competitive Inhibitor
CRISPR
Crossing Over
Cyclin
Denaturation
Depolarization
DNA Polymerase
Electron Transport Chain
Endosymbiosis
Epigenetic
Eutrophication
Exon
Feedback Inhibition
Fluid Mosaic Model
Frameshift Mutation
Gene Pool
Genetic Drift
Glycolysis
Hardy-Weinberg
Helicase
Induced Fit
Intron
Keystone Species
Krebs Cycle
Logistic Growth
Lymphocyte
Meiosis
Methylation
Mitosis
mRNA
Mutualism
Myosin
Negative Feedback
Non-Disjunction
Nucleosome
Okazaki Fragment
Oncogene
Operon
PCR
Phloem
Photolysis
Photosystem II
Phylogeny
Plasmolysis
Pluripotent
Reproductive Isolation
Resting Potential
RuBP
Rubisco
Signal Transduction
Speciation
Telomere
Transcription Factor
Transpiration
Trophic Level
Tumor Suppressor Gene
Water Potential
Xylem
Zygote

…and 1,400+ more terms in the full app.

AP Biology Revision FAQ

What units are in AP Biology?

AP Biology is divided into 8 units: Unit 1 Chemistry of Life, Unit 2 Cell Structure and Function, Unit 3 Cellular Energetics, Unit 4 Cell Communication and Cell Cycle, Unit 5 Heredity, Unit 6 Gene Expression and Regulation, Unit 7 Natural Selection, and Unit 8 Ecology.

The AP exam tests all 8 units across Section I (60 multiple choice + 6 grid-in questions) and Section II (2 long FRQs + 4 short FRQs).

How hard is AP Biology?

AP Biology is considered one of the more demanding AP sciences. It covers a very broad range of content from biochemistry to ecology, requires strong vocabulary, and tests your ability to apply concepts to experimental scenarios you haven't seen before.

Students who perform best combine consistent vocabulary practice (flashcards, spaced repetition) with regular FRQ writing and data analysis practice using College Board released materials.

What is the best way to study for AP Biology?

Active recall — test yourself constantly rather than rereading. Flashcards and games like Cramly's Recall mode (where you type as many biology terms as possible against a timer) force your brain to retrieve information, which strengthens retention far more than passive review.

Spaced repetition — Cramly's algorithm handles this automatically, showing you cards you struggle with more frequently and spacing out cards you've mastered.

FRQ practice — AP Biology FRQs reward precise biological language and structured answers. Use College Board released FRQs and mark schemes to practice the exact phrasing examiners expect.

Is Cramly free for AP Biology?

Yes — completely free. No premium plan, no paywall, no credit card required. All flashcards, games, and progress tracking are available at no cost.

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