Connect water’s molecular interactions to biological evidence
Annotate a molecular representation and distinguish an interaction explanation from a thermal model output.
AP Biology preparation
Connect molecular mechanisms to biological evidence, design comparisons and explain what an observation can—and cannot—establish.
This is the course outline. Open a unit to choose a lesson; every lesson opens on its own page. Explanations and experiments live inside those lesson pages.
Course scope and preparation
Biological mechanisms and investigation
70 authored lessons are organized into the implemented modules below. Compare mechanisms, inspect supplied records, construct representations and justify what the evidence supports. Each notebook belongs to this AP preparation course rather than the school foundation. The eight content units and cumulative category are authored, including twelve investigation portfolios, a cross-scale project and six mixed written tasks. These are available in the retained evidence workspace. Authored curriculum does not establish learner mastery, AP authorization or completion of supervised practical requirements.
Recommended foundations are high-school biology and chemistry. Familiar material is directly accessible; no previous page completion is required to enter these lessons. Existing foundation notebooks remain separate from deeper AP evidence.
Chemistry of life — opening investigations
Explain water’s thermal buffering without confusing heat and temperature
Calculate controlled temperature changes and explain biological implications while retaining phase and heat-transfer limits.
Use molecular groups to frame biological predictions
Identify biological elements and functional groups, and distinguish neutral bookkeeping from conditional protonation.
Account for biological links without inventing a synthesis mechanism
Reconcile peptide fragments and water while distinguishing a net equation from activated biosynthesis.
Explain carbohydrate differences through linkages and branches
Relate carbohydrate architecture to bounded functional hypotheses while separating a graph rule from an enzyme experiment.
Connect lipid architecture to organization in water
Explain lipid structural contrasts and conditional packing predictions while distinguishing atom accounting from measured membrane behavior.
Read nucleic-acid structure with chemical identity and direction
Construct complementary strands with explicit orientation and distinguish a pairing check from synthesis or thermodynamics.
Distinguish protein organization from backbone cleavage
Distinguish conformational change, peptide hydrolysis and evidence for function.
Test a molecular explanation against independent evidence
Distinguish chemical and functional claims, retain uncertainty and propose a discriminating follow-up.
Cell structure and function — opening investigations
Explain how cell compartments coordinate a protein’s route
Explain compartmentalization and trace one selected secretory route without treating it as the destination of every protein.
Distinguish cargo transport changes from a smaller starting pulse
Use a conserved pulse and compartment-specific comparisons to evaluate bounded transport hypotheses.
Compare cell exchange geometry without mistaking area for flux
Calculate surface-area-to-volume comparisons and explain the assumptions connecting geometry with transport, heat and demand.
Explain membrane structure and evaluate passage evidence
Connect membrane structure with selective permeability and identify controls for causal claims.
Distinguish passive driving forces from transport rates
Use signed energy contributions to justify a conditional passive direction and design a comparison that tests route availability.
Account for active transport and vesicle topology
Conserve ion inventories, distinguish direct and indirect energy coupling, and track cargo across vesicle formation and fusion.
Infer water movement and an unknown solution with limits
Predict conditional water movement and justify an unknown-concentration bracket while distinguishing interpolation, replicate variation and readout bounds.
Evaluate compartment function and endosymbiotic origins
Explain compartment benefits and justify an endosymbiotic inference using multiple evidence families without overstating their independence.
Cellular energetics — mechanisms and evidence
Explain catalysis and choose an initial-rate window
Distinguish activation barrier from overall energy change and calculate a justified interval rate.
Distinguish enzyme perturbations with controlled evidence
Identify nonunique kinetic explanations and propose discriminating controls and recovery evidence.
Trace energy coupling through an activated intermediate
Explain why a coupling mechanism is needed and relate sequential reactions to material conservation, energy use and maintained cellular organization.
Trace photosynthetic electrons and proton coupling
Connect water oxidation, photosystems, electron transfer and chemiosmosis while distinguishing immediate constraints from sustained effects.
Audit carbon fixation and distinguish pathway evidence
Audit a complete-cycle carbon account and design evidence that distinguishes carbon incorporation from oxygen production.
Trace respiration and explain fermentation’s carrier-recycling role
Explain why NAD⁺ regeneration permits repeated glycolytic ATP production and distinguish substrate-level phosphorylation from respiratory chemiosmosis.
Distinguish respiratory disruptions with matched evidence
Explain respiratory membrane topology and distinguish leak, terminal-acceptor interruption and synthase blockage using rates, transients and measurement limits.
Build an energetics argument from paired oxygen evidence
Calculate justified interval rates and defend a bounded production/consumption claim with separate measurement, replication and biological-assumption limits.
Cell communication and cell cycle
Explain signaling distance and receptor specificity
A distant hormone reaches two tissues, but only one changes enzyme activity. Give two compatible explanations and a discriminating measurement.
Trace reception, relay and cellular response
Draw a three-arrow pathway and label one place where the response could end while ligand remains present.
Locate a signaling defect with rescue controls
You have one further assay. Choose between measuring only final Y again or measuring K activity after R activation, and justify the choice.
Distinguish stabilizing feedback from reinforcement
A regulator releases more of a corrective substance when its target variable falls. Is that positive feedback? State the missing relationship.
Track DNA and chromosome number through a cell cycle
A species has 2n=10. Give chromosome and chromatid counts in G2 and in each normal daughter after mitosis.
Infer stage durations cautiously from cell samples
Explain why selecting only fields with many visible chromosomes biases the estimate and propose a sampling repair.
Explain cell-cycle checkpoints and loss of regulation
Propose two measurements that distinguish temporary arrest from irreversible loss of proliferative capacity after damage.
Heredity
Track homologs and chromatids through meiosis
For 2n=12, draw one post-meiosis-I nucleus and state chromosomes, chromatids and ploidy.
Explain crossing over and assortment without mixing mechanisms
A student uses 2^3=8 to claim exactly eight children from a three-pair organism must have different genomes. Repair the claim.
Derive cross probabilities and distinguish expectation from outcome
For two independent offspring of Aa × Aa, calculate the probability that exactly one is aa.
Use a testcross to estimate recombination and retain limits
Why can a low recombinant percentage support linkage, while 50% cannot prove different chromosomes?
Test an inheritance null with chi-square reasoning
If the fourth expected count were 1, what would you check before using the same reference distribution?
Distinguish dominance, codominance and multiple alleles
A common allele is recessive for a trait. Does its frequency contradict recessiveness? Explain.
Interpret chromosome-linked and cytoplasmic inheritance
An affected father and unaffected mother have no affected sons. Why does that alone not prove X linkage?
Separate genotype, environment and their interaction
Design a cross to distinguish genetic segregation from an environmental color response without testing humans or manipulating harmful organisms.
Gene expression and regulation
Use complementary evidence to identify inherited information
A nucleic-acid sample has 30% adenine. Under what assumption can you infer 30% thymine, and what still cannot be inferred?
Trace antiparallel replication and repair limits
Write the complementary strand to 5′-ACGTTA-3′ first aligned beneath it, then in 5′→3′ notation.
Predict transcripts and distinguish processing from translation
RNA doubles after treatment. Propose a measurement that separates faster production from slower degradation.
Trace a reading frame from initiation to termination
Explain why a one-nucleotide insertion early in a coding region can have a broader effect than a three-nucleotide insertion.
Distinguish transcriptional control from downstream effects
A reporter signal rises when a proposed enhancer is present. Give controls that distinguish enhancer action from unequal cell number and different copy number.
Explain differentiated cells with shared genetic information
Why would sequencing only the two marker genes be insufficient to explain the difference between two cell types?
Separate sequence predictions from functional outcomes
A student sees a premature stop and states the organism must have a severe phenotype. Give two reasons the prediction is incomplete.
Interpret gel and expression evidence with controls
Two samples have a band at the same position. Propose a safe analytical follow-up that distinguishes identical size from identical sequence.
Natural selection
Connect heritable variation to relative reproductive success
A variant survives twice as well but produces half as many offspring per survivor. Under a simple product model, compare its total contribution with the reference.
Distinguish selection by people from inheritance and trade-offs
Design a paper-only analysis that distinguishes a selected-line response from a seasonal growing-condition change.
Separate drift, gene flow and mutation from selection
Would two equal neutral populations necessarily show the same allele-frequency change? Explain what replication reveals.
Calculate allele frequencies and test equilibrium claims
In a population with AA=18,Aa=24,aa=8, calculate p directly and expected Aa under random union.
Combine fossils, homology and molecular evidence
Why does a shared flying function not by itself establish that two wing structures evolved once?
Read a longitudinal evolution study without inventing observations
Write one sentence reporting the published result and a separate sentence describing the synthetic packet, without merging them.
Read branching relationships rather than tip order
Draw ((A,B),C) twice with different tip orders; identify the same sister pair and explain why C is not an ancestor of A.
Explain reproductive barriers and divergence
What evidence would distinguish a behavioral mating barrier from reduced hybrid fertility?
Relate variation, changing environments and extinction
Propose two measurements beyond allele count needed to evaluate persistence without promising survival.
Separate origin-of-life hypotheses from ancestry evidence
Name evidence that would be needed to move from organic-molecule formation toward a claim about an evolving protocell system.
Ecology
Distinguish directional responses, activity and fitness
What additional trajectory measurement would discriminate directed movement from slower random movement in darkness?
Track energy flow and distinguish production from standing biomass
A lake has low instantaneous producer biomass but rapid producer turnover. Can consumer biomass temporarily exceed producer biomass without violating energy conservation?
Estimate abundance with sampling assumptions and uncertainty
If marked individuals avoid recapture, which direction of bias would you expect from MC/R, holding other counts fixed?
Compare exponential and density-limited growth models
For r=0.2/year,K=1000,N=1200, find the logistic instantaneous rate and interpret its sign.
Use per-capita evidence to identify density dependence
Explain why a drought cannot automatically be classified from the word drought alone in every dataset.
Infer direct and indirect interactions from controlled contrasts
Design a supplied-data factorial comparison that separates predator presence from nutrient limitation.
Separate richness, evenness and sampling completeness
If a second site was sampled for twice as long and yielded more species, what prevents a direct richness comparison?
Connect disturbance, nutrient cycles and evidence-based intervention
Specify an evidence plan for evaluating habitat restoration without releasing organisms or applying chemicals yourself.
Cumulative investigations and review
Build a falsifiable investigation and evidence portfolio
Draft a one-page preregistered paper-only study with two competing mechanisms and a measurement that would separate them.
Connect molecular change to organism and population evidence
Write a causal diagram and propose one control for each arrow from variant to expression/function to phenotype to reproduction.
Audit mixed evidence before revealing a worked response
Before opening feedback, answer three prompts: calculate the expected count, propose two biological alternatives, and propose one technical control that could discriminate them.
Defend conclusions, identify gaps and plan next evidence
Prepare a brief defense of one supported claim and one remaining uncertainty, then name the next safe evidence that would change your conclusion.
Projects, practice and evidence
What the evidence means
The eight-residue chain is an original teaching example. Its atom ledger verifies a stipulated chemical accounting problem; its compact and extended depictions do not predict real protein folds, biological activity or reaction rates. Public practice and notebook presence do not certify independent understanding.
The College Board course audit requires documented, educator-supervised investigations and appropriate lab time and distribution. Permitted virtual investigations still require student work and supervision. This site supplies preparation materials; it does not establish AP authorization, credit or completion of those requirements.
Save a science backup or import one
Science work is stored locally in this browser, separately from mathematics and AI. It does not sync automatically. Use this science-only backup; this checkout's older all-subject export does not include science.
A legacy file is available only when the complete snapshot fits the 36 MB limit. For larger snapshots, prepare a complete file set below; never discard notebooks to make a smaller file.
Matching imported notebook drafts replace their current drafts. Omitted lessons and known first attempts remain. Export your current work first if you want to retain both drafts.
Complete file sets and course backups
A file set can hold more work than one science file. Keep its manifest and every part together. Each file is limited to 36 MB. This format needs this version of LearnAI or a compatible newer version; older versions can use only the legacy single-file backup above.
The set includes every saved science course and global continuation at this moment. Later edits need a new export. A conflicting tab exports its own visible work, which may differ from saved work in another tab.
0 file(s) selected. File order and filenames do not determine identity. Missing, changed or conflicting parts block the entire restore; no good part is applied by itself.
Science storage: loading. No account or remote computation is required.