DATTRAIN is turning the official Biology scope into an objective-level learning system—publicly mapped, source-linked, and free. This page shows exactly what is ready and what still requires review.
The ADA publishes 40 Biology questions and the hierarchy below. It does not publish a question quota or percentage for each Biology domain, so DATTRAIN does not present one.
The 48 detailed outcomes on this page are DATTRAIN instructional planning objectives—not ADA-authored objectives and not a prediction of test distribution.
Official 2026 content specification
Five domains. Forty-three subtopics.
Labels below preserve the wording used in the official manual for auditability. Where terms such as “Archaebacteria,” “Eubacteria,” and “Protista” reflect older classification conventions, lessons will teach current scientific terminology and explain the mapping.
Every objective declares what a learner should be able to do, the knowledge boundary, prerequisites, a known misconception, expected representations, and free sources. Official legacy labels remain visible while current scientific terms appear in the outcomes.
BCellular processes (including membrane transport, signal transduction)3 objectives
BIO-CMB-CP-01source-mapped
Passive and active membrane transport
Classify transport mechanisms and predict solute movement from gradients, membrane permeability, and energy coupling.
Must know
Simple and facilitated diffusion move down an electrochemical gradient. Primary and secondary active transport require direct or indirect energy input.
Depth boundary
Named transporter details are required only when a prompt supplies them.
Misconception to disarm
Facilitated diffusion requires ATP because it uses a protein. Carrier or channel use does not make transport active; direction relative to the gradient determines that.
Predict water movement and cell-volume change while distinguishing osmolarity from effective tonicity.
Must know
Water moves toward higher effective nonpenetrating-solute concentration. Tonicity depends on membrane permeability as well as solute concentration.
Depth boundary
Quantitative osmotic-pressure calculations are outside this objective unless the equation is provided.
Misconception to disarm
Water moves toward the side with more total solute in every case. Penetrating solutes may equilibrate and therefore contribute differently to tonicity.
Infer cellular responses from receptor location, relay steps, amplification, second messengers, and feedback.
Must know
Hydrophilic signals commonly use cell-surface receptors; many hydrophobic signals use intracellular receptors. Cascades can amplify signals and create multiple points of regulation.
Depth boundary
Named signaling pathways are assessed through supplied context rather than exhaustive protein memorization.
Misconception to disarm
Every signaling molecule enters its target cell. Many signals bind membrane receptors and transmit information through intracellular relays.
Apply conservation of energy and entropy to biological transformations and open cellular systems.
Must know
Cells transform energy; they do not create it. Local order can increase while total entropy of the system plus surroundings increases.
Depth boundary
No calculus-based derivations of thermodynamic state functions.
Misconception to disarm
Living cells violate the second law because they become organized. Cells are open systems and increase the entropy of their surroundings while maintaining local order.
Use the sign of ΔG and reaction coupling to predict spontaneity, work, and metabolic direction under stated conditions.
Must know
A negative ΔG indicates thermodynamic favorability, not necessarily a fast rate. Coupled reactions can have a negative net ΔG even when one step is endergonic.
Depth boundary
Numerical ΔG calculations require supplied values and equations.
Misconception to disarm
A spontaneous reaction must occur rapidly. Thermodynamic favorability and kinetic rate are different properties.
Track DNA content, chromosome state, and sister-chromatid movement through the cell cycle and mitosis.
Must know
DNA replication occurs in S phase before mitosis. Sister chromatids separate at anaphase while chromosome number is defined by centromeres.
Depth boundary
Cyclin names beyond broad checkpoint control are not required without prompt context.
Misconception to disarm
Chromosome number doubles immediately after S phase. DNA amount doubles, but duplicated sister chromatids remain one chromosome until their centromeres separate.
Explain how independent assortment, crossing over, random fertilization, and nondisjunction affect offspring genotypes and chromosome counts.
Must know
Independent assortment and crossing over generate distinct sources of variation. The meiotic division in which nondisjunction occurs changes the gamete pattern.
Depth boundary
Named syndromes are examples, not the main memorization target.
Misconception to disarm
Nondisjunction in meiosis I and meiosis II produces the same four gametes. Meiosis I errors affect homolog separation; meiosis II errors affect sister-chromatid separation and yield different gamete patterns.
Compare cell types and infer how compartmentalization, size, and shared structures relate to function.
Must know
Both cell types have DNA, ribosomes, cytosol, and a plasma membrane. Membrane-bound organelles distinguish eukaryotic internal organization.
Depth boundary
Taxonomic exceptions are used only when the prompt establishes them.
Misconception to disarm
Prokaryotes have no organelles or internal organization. They lack classic membrane-bound organelles but contain organized molecular structures and may have specialized membranes.
Relate membrane fluidity, cytoskeletal elements, extracellular matrix, and cell junctions to shape, movement, transport, and tissue integrity.
Must know
Membranes are dynamic mosaics whose composition affects fluidity and permeability. Cytoskeletal elements and junctions perform distinct mechanical and transport roles.
Depth boundary
Individual motor-protein isoforms are not required without context.
Misconception to disarm
The plasma membrane is a rigid, fixed barrier. Lipids and many proteins move laterally, and membrane properties change with composition and conditions.
Identify independent and dependent variables, choose positive and negative controls, and distinguish replication from repeated measurement.
Must know
A control isolates the effect of the tested variable. Independent biological replicates support generalization better than repeated readings of one sample.
Depth boundary
Formal power analysis is outside this objective.
Misconception to disarm
Three readings from one culture are three biological replicates. They are technical repeats unless they come from independently prepared biological samples.
Read biological tables and graphs, separate correlation from causation, and identify conclusions justified by an experimental design.
Must know
A result can reject a prediction without proving every alternative mechanism. Association alone does not establish causation or direction.
Depth boundary
Advanced inferential statistics are not required unless explained in the prompt.
Misconception to disarm
A statistically significant association proves the proposed mechanism. Significance addresses compatibility with a null model, not whether a specific mechanism is true.
Relate carbohydrates, lipids, proteins, and nucleic acids to their building blocks, bonds, properties, and cellular roles.
Must know
Structure and functional groups shape intermolecular behavior. Dehydration and hydrolysis respectively form and break many biological polymers.
Depth boundary
Exhaustive lipid nomenclature is outside this objective.
Misconception to disarm
Lipids are true polymers made from one repeating monomer. Major lipid classes are assembled from components but generally are not repeating-monomer polymers.
Specific protein structures are assessed only when introduced or broadly canonical.
Misconception to disarm
Denaturation normally breaks the protein into amino acids. It usually disrupts secondary, tertiary, or quaternary structure while peptide bonds remain intact.
Compare DNA, RNA, nucleotides, and ATP by components, bonds, directionality, stability, and information or energy-transfer roles.
Must know
Phosphodiester bonds create 5′-to-3′ nucleic-acid backbones. Base pairing and antiparallel strands support templated information transfer.
Depth boundary
Rare modified bases and specialized RNA chemistry are outside this objective.
Misconception to disarm
ATP stores energy in a bond that releases energy simply when broken. Hydrolysis is favorable because the products and their interactions are more stable; bond breaking itself requires energy.
Trace a secreted or membrane protein from synthesis through processing, sorting, vesicle transport, and destination.
Must know
Signal information directs proteins into the endomembrane system. Rough ER, Golgi, vesicles, and membrane act in an ordered trafficking pathway.
Depth boundary
Individual coat-protein and SNARE names are not required without prompt context.
Misconception to disarm
All proteins are synthesized on permanently different ribosome types. Free and ER-bound ribosomes are part of one pool; targeting signals determine where translation continues.
Predict how extracellular signals, feedback, and checkpoints coordinate cell behavior and tissue homeostasis.
Must know
Checkpoint passage depends on internal state and extracellular information. Negative feedback stabilizes many systems, while positive feedback drives selected transitions.
Depth boundary
Named cancer genes are examples rather than an exhaustive list.
Misconception to disarm
Positive feedback is always harmful and negative feedback always suppresses a process. Feedback describes how output changes the initiating signal; either form can serve normal physiology.
Relate viral genomes, capsids, optional envelopes, and attachment proteins to host dependence and infectivity.
Must know
Virions contain a nucleic-acid genome and structural proteins but lack complete independent cellular machinery. Envelope status, genome chemistry, capsid form, host range, and sequence relationships are distinct classification evidence.
Depth boundary
Exact family-level taxonomy is supplied when required; this objective emphasizes transferable structural logic.
Misconception to disarm
Every virus contains both DNA and RNA and can synthesize proteins independently. A virion has a DNA or RNA genome and depends on compatible host-cell machinery for protein synthesis and progeny production.
Order common infection stages and distinguish productive, lytic, lysogenic, latent, and budding outcomes from supplied evidence.
Must know
Productive infection generally requires attachment, entry, genome access, component production, assembly, and release. A prophage can persist with the bacterial chromosome and later be induced into lytic replication.
Depth boundary
Virus-specific exceptions and molecular proteins are required only when a prompt supplies them.
Misconception to disarm
Every viral release event immediately lyses the host cell. Some enveloped viruses bud without immediate lysis, although infection may still damage or later kill the cell.
Infer how viral genome strategies generate translatable mRNA and evaluate conclusions from perturbation and infectivity experiments.
Must know
Positive-sense mRNA is the common checkpoint for host-ribosome translation. Physical particles, genome copies, binding events, and infectious units measure different quantities.
Depth boundary
The complete Baltimore system is used as a reasoning framework, not as a list of disease associations to memorize.
Misconception to disarm
A lower plaque count proves that the viral genome was destroyed. Plaque loss shows fewer successful infectious events; an attachment, entry, genome, expression, assembly, or spread defect could cause it.
Archaea: current classification and cell structure
Map the official label “Archaebacteria” to domain Archaea and compare archaeal, bacterial, and eukaryotic cell features.
Must know
Archaea and Bacteria are distinct prokaryotic domains. Archaeal membranes and cell envelopes differ chemically from typical bacterial structures, and archaeal information-processing systems share selected similarities with eukaryotes.
Depth boundary
Named archaeal phyla are not required unless introduced.
Misconception to disarm
Archaea are simply bacteria that live in extreme environments. Archaea are a distinct domain, and many live in ordinary as well as extreme environments.
Relate archaeal metabolic diversity and environmental adaptations to ecological roles.
Must know
Archaea include diverse chemotrophs and phototrophs, and methanogenesis is restricted to archaeal lineages. Extremophile labels describe favored conditions rather than universal domain traits.
Depth boundary
Exact pathway enzymes and genus-level habitat lists are outside the objective.
Misconception to disarm
All archaea are photosynthetic pathogens. Archaea have varied metabolisms, and no archaeal species is established as a primary human pathogen in the conventional sense.
Explain archaeal asexual reproduction, horizontal gene exchange, and phylogenetic evidence without treating prokaryotes as one lineage.
Must know
Archaea reproduce asexually rather than by mitosis or meiosis. Sequence evidence distinguishes Archaea from Bacteria and can reveal horizontal transfer as well as vertical descent.
Depth boundary
Specialized archaeal recombination systems are supplied if assessed.
Misconception to disarm
All prokaryotes form one natural domain because they lack nuclei. The shared prokaryotic cell plan does not erase the deep evolutionary distinction between Archaea and Bacteria.
Map the official label “Eubacteria” to domain Bacteria and predict function from bacterial envelopes, shapes, and surface structures.
Must know
Bacterial walls commonly contain peptidoglycan, while Gram-positive and Gram-negative envelopes differ. Shape and stain response are useful traits but do not alone define full phylogeny or metabolism.
Depth boundary
Clinical identification panels and exhaustive species lists are outside the objective.
Misconception to disarm
Every bacterium is harmful and Gram stain reveals its exact species. Most bacterial relationships with hosts and ecosystems are not pathogenic, and staining is one classification clue among many.
Classify bacterial energy and carbon strategies and connect them to decomposition, nutrient cycling, symbiosis, and disease.
Must know
Energy source and carbon source are separate axes of metabolic classification. Bacteria drive major carbon and nitrogen transformations and can be mutualists, commensals, or pathogens.
Depth boundary
Exact enzyme sequences and species-specific clinical syndromes are supplied when needed.
Misconception to disarm
All autotrophs use sunlight and all heterotrophs use oxygen. Photo- and chemo- describe energy sources, while auto- and hetero- describe carbon sources; oxygen use is another independent trait.
Predict population and genotype consequences of binary fission, mutation, transformation, transduction, and conjugation.
Must know
Binary fission is asexual cell reproduction, while horizontal transfer changes genotype without creating offspring by itself. Selection acts on variation generated by mutation and gene movement.
Depth boundary
Detailed plasmid maps and named transfer systems are required only when supplied.
Misconception to disarm
Conjugation is bacterial sexual reproduction that directly produces a new cell. Conjugation transfers DNA between cells; cell-number increase occurs through division such as binary fission.
Relate chitinous walls, hyphae, mycelia, and extracellular digestion to fungal growth and nutrition.
Must know
Fungi are heterotrophic eukaryotes that generally digest externally and absorb nutrients. Hyphal growth produces a large exchange surface, while yeasts are commonly unicellular.
Depth boundary
Genus-level morphology is not required without context.
Misconception to disarm
Fungi are photosynthetic plants without leaves. Fungi are heterotrophs with absorptive nutrition and chitin-rich walls, not photosynthetic plants.
Evaluate fungal roles as decomposers, pathogens, mutualists, and partners in lichens and mycorrhizae.
Must know
Fungal decomposition recycles nutrients from organic matter. Mycorrhizal and lichen associations involve reciprocal exchanges whose partners remain biologically distinct.
Depth boundary
Named toxin and pathogen lists are outside the objective unless introduced.
Misconception to disarm
All fungi are either parasites or decomposers with no mutualistic roles. Many fungi form nutrient-exchange mutualisms with plants, algae, cyanobacteria, or animals.
Map the official label “Protista” to diverse eukaryotic lineages and use phylogeny rather than one assumed natural kingdom.
Must know
The historical kingdom Protista does not form one monophyletic lineage in current classification. Protists include varied unicellular, colonial, and multicellular eukaryotes across several branches.
Depth boundary
A single fixed supergroup scheme is not treated as timeless when relationships remain under revision.
Misconception to disarm
All protists are more closely related to one another than to plants, animals, or fungi. The historical category spans multiple eukaryotic branches; some protists are closer to particular multicellular groups than to other protists.
Relate pseudopodia, cilia, flagella, photosynthesis, ingestion, absorption, and mixotrophy to protist function.
Must know
Similar feeding or locomotor forms can evolve in distantly related lineages. Mixotrophs can combine nutritional modes as conditions change.
Depth boundary
Species identification by fine morphology is outside the objective.
Misconception to disarm
Every photosynthetic protist is a plant and every mobile protist is an animal. Nutrition and motility traits do not by themselves place a eukaryote in Plantae or Animalia.
Interpret protist life cycles and roles as primary producers, symbionts, decomposers, and pathogens.
Must know
Protist life cycles can include asexual and sexual stages in different hosts or environments. Aquatic photosynthetic protists support food webs and global element cycles.
Depth boundary
Disease-vector details are supplied when required.
Misconception to disarm
Protists are ecologically minor because most are microscopic. Microscopic protists can dominate primary production, symbioses, decomposition, and disease processes.
Relate protected embryos, cuticle, stomata, vascular tissue, seeds, and flowers to plant diversification on land.
Must know
Land plants share ancestry with green-algal lineages. Major innovations alter water balance, transport, reproduction, and dispersal rather than forming a simple ladder of progress.
Depth boundary
Order- and family-level botany is outside the objective.
Misconception to disarm
Modern bryophytes are direct ancestors of modern flowering plants. Living groups share ancestors and represent branching lineages, not a chain in which one modern group turns into another.
Relate roots, stems, leaves, meristems, xylem, phloem, and stomata to resource acquisition, transport, and growth.
Must know
Xylem and phloem differ in transported material, driving forces, and living components. Stomata coordinate carbon-dioxide entry with water loss.
Depth boundary
Detailed hormone networks belong in the systems domain unless supplied.
Misconception to disarm
Phloem always moves material downward and xylem always moves living sugars. Xylem primarily transports water and minerals, while phloem moves organic solutes from sources to sinks in directions set by their locations.
Track ploidy and structures through plant alternation of generations, pollination, fertilization, seed formation, and fruit formation.
Must know
Meiosis makes haploid spores, not gametes, in the generalized plant cycle. The gametophyte makes gametes by mitosis; fertilization restores diploidy.
Depth boundary
Species-specific flower morphology is outside the objective unless diagrammed.
Misconception to disarm
Plant meiosis directly produces sperm and eggs in the same way as animal gametogenesis. Plant meiosis produces spores that grow into gametophytes; those haploid organisms make gametes by mitosis.
Use shared derived traits and supplied phylogenies to compare major invertebrate and vertebrate lineages.
Must know
A clade contains an ancestor and all descendants. Shared derived characters are more informative than general resemblance or habitat.
Depth boundary
The objective prioritizes diagnostic relationships over exhaustive class and order lists.
Misconception to disarm
Evolutionary relatedness can be read as a ranking from simple to advanced. Phylogenies show branching ancestry, not a universal ladder of complexity or value.
Identify an unknown biological entity by integrating cellular organization, envelopes, nutrition, reproduction, and molecular evidence.
Must know
No single trait reliably separates every group in every case. Viruses, prokaryotic domains, and eukaryotic lineages require different but compatible comparison axes.
Depth boundary
Prompts supply uncommon exceptions that would defeat broad diagnostic rules.
Misconception to disarm
One trait such as movement, a wall, or photosynthesis uniquely identifies every group. Classification integrates multiple independent traits and evolutionary evidence.
Interpret trees and character data while separating homology, analogy, vertical descent, and horizontal transfer.
Must know
Nodes represent common ancestors, and rotations around a node do not change relationships. Sequence and structural evidence can conflict because of convergence, rate differences, sampling, or horizontal gene transfer.
Depth boundary
Tree-building algorithms are not calculated unless supplied.
Misconception to disarm
Species drawn next to one another at the tips are necessarily closest relatives. Relatedness is determined by the recency of shared branching nodes, not tip spacing or left-to-right order.
Predict how producers, consumers, decomposers, symbionts, pathogens, and viruses alter community processes and selection.
Must know
An organism’s lineage does not fix one ecological role across all contexts. Interactions can change population growth, nutrient cycling, gene frequencies, and coevolutionary pressures.
Depth boundary
Quantitative population models belong in Evolution and Ecology unless equations are supplied.
Misconception to disarm
Every interaction has one permanent positive or negative effect for each participant. Interaction outcomes can depend on environment, life stage, density, and the trait being measured.