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Edexcel Biology 9BN0 and 9BI0: the route maps

Pearson Edexcel offers two separate A-level Biology qualifications. Biology A (Salters-Nuffield), 8BN0/9BN0, is context-led; Biology B, 8BI0/9BI0, follows a conventional topic structure. Use the jump links below to open the map for your qualification. Each map was checked against its own Issue 4 specification on 21 August 2026 and states any gaps.

Nothing on either half of this page may be read across to the other: the two number their statements differently and set different core practicals.

Jump to: Biology A (Salters-Nuffield) · Biology B

Start with the topic notes · questions by topic, with mark schemes · the practical work · where the real past papers are · the definitions · flashcards · a revision checklist.

Biology A (Salters-Nuffield) 8BN0/9BN0

The context-led route. A row here is one numbered statement, which is the level the specification cross-references and the level it assesses; where a statement is served in one of its lettered sub-parts and not in another, the row says so and names the sub-part. The short label on each row is ours: this specification numbers its statements and does not title them, so the label is a name written here for navigation and the statement itself is the board's. The check was made on 21 August 2026, against the specification, Issue 4 (November 2018).

Some statements on this route are taught by nothing in this library at all. Those rows say so in the table below, each with what is absent written beside it, and they are not the same thing as a statement the board excuses you from.

1 Lifestyle, Health and Risk

Ref	Specification heading	Taught in	Coverage
1.1	Why animals have a heart and circulation	The heart and cardiac cycle, Surface area to volume ratio: why size limits diffusion	Covered
1.2	Water as a transport solvent, and its dipole	Water and inorganic ions	Covered
1.3	Structure of capillaries, arteries and veins	Blood vessels, tissue fluid and lymph	Covered
1.4	The cardiac cycle and the mammalian heart	The heart and cardiac cycle, Dissection and biological drawing	Covered
1.5	The course of atherosclerosis	Cholesterol, atheroma and what a risk factor means	Covered
1.6	Blood clotting and its role in CVD	Cholesterol, atheroma and what a risk factor means	Covered
1.7	Risk factors for cardiovascular disease	Cholesterol, atheroma and what a risk factor means, Diet, energy and how to read a health claim	Covered
1.8	Interpreting illness and mortality data	Diet, energy and how to read a health claim, Variables and controls: what an experiment can show, Handling data: units, scales, rates and uncertainty	Covered
1.9	Evaluating the design of health-risk studies	Diet, energy and how to read a health claim, Variables and controls: what an experiment can show, Averages, spread and the null hypothesis	Covered
1.10	Perception of risk against actual risk	Diet, energy and how to read a health claim	Covered except: why people over- and underestimate a risk. The arithmetic of risk is taught -- relative against absolute, the missing denominator, and why a scare and a real finding look identical in print -- but the psychology the board asks for, the reasons a familiar or voluntary risk feels smaller than a rare and dramatic one, is not written anywhere here.
1.11	Energy budgets, energy imbalance and obesity	Diet, energy and how to read a health claim, Regulation of blood glucose and diabetes mellitus	Covered
1.12	Mono-, di- and polysaccharides and energy	Carbohydrate structure and function, Qualitative biochemical tests, and what they do not tell you, Colorimetry, dilution series and calibration curves	Covered
1.13	Condensation, glycosidic bonds and hydrolysis	Carbohydrate structure and function	Covered
1.14	Triglycerides, ester bonds, saturation	Lipids: triglycerides, phospholipids and ester bonds	Covered
1.15	Blood cholesterol, HDL, LDL and causation	Cholesterol, atheroma and what a risk factor means	Covered
1.16	Using knowledge of diet and lifestyle to cut CHD risk	Diet, energy and how to read a health claim, Cholesterol, atheroma and what a risk factor means	Concept covered; the board's example is not: waist-to-hip ratio. Body mass index is worked as a calculation with two reasons it misleads, and the second of those reasons is where the fat sits -- but the ratio this library then prints is waist to height, not waist to hip. A candidate asked for the board's named indicator would give the wrong one.
1.17	Ethics of using invertebrates in research		Nothing here teaches this: Nothing here discusses the use of invertebrates in research or the ethical arguments about it. Eight lessons carry ethical argument and every one of them is about something else: embryonic stem cells, cloning, genetic modification, screening and the right not to know, vaccination, conservation priorities. This is a Salters-Nuffield context -- it hangs off the Daphnia heart-rate practical -- and the library was written to a syllabus-neutral biology that never raised it. It is the same gap as 8.12, at the other end of the qualification.
1.18	Benefits and risks of CVD treatments	Cholesterol, atheroma and what a risk factor means	Covered except: antihypertensives, anticoagulants and platelet inhibitors. Statins are the one class treated properly -- the rate-limiting enzyme they inhibit, why they lower blood cholesterol further than diet does, and the risk threshold at which one is offered -- and the other three classes named by the board have no mechanism, no benefit and no risk written here. Anticoagulants appear only as a pharmacogenomics example (warfarin) and as a product of transgenic goats.

2 Genes and Health

Ref	Specification heading	Taught in	Coverage
2.1	Gas exchange surfaces, Fick's law and the lung	Surface area to volume ratio: why size limits diffusion, Gas exchange in mammals: lungs and ventilation, Diffusion and osmosis	Covered
2.2	Cell membranes and the fluid mosaic as a model	Membrane structure and the fluid mosaic model, Investigating membrane permeability	Covered
2.3	Osmosis as the movement of free water molecules	Diffusion and osmosis, Water relations of plant tissue: osmosis and transpiration, Non-living models of diffusion, osmosis and surface area	Covered
2.4	Passive and active transport, endo- and exocytosis	Diffusion and osmosis, Active transport, co-transport and bulk transport	Covered
2.5	Mononucleotides and the DNA double helix	DNA and RNA structure	Covered
2.6	Transcription and translation	The genetic code and transcription, Translation and protein synthesis	Covered
2.7	The nature of the genetic code	The genetic code and transcription	Covered
2.8	What a gene is	The genetic code and transcription	Covered
2.9	Amino acids, polypeptides and protein structure	Protein structure and function, Haemoglobin and oxygen dissociation curves	Covered
2.10	Enzyme action, specificity and location	Enzyme action and specificity, Cofactors, coenzymes and where enzymes work, Factors affecting enzyme rate: temperature, pH and concentration, Measuring the rate of an enzyme-controlled reaction	Covered
2.11	DNA replication and Meselson and Stahl	DNA replication	Covered
2.12	Replication errors, mutation and cystic fibrosis	DNA replication, Mutation, gene expression and cancer, Genome analysis, genetic screening and gene therapy	Covered
2.13	Genetic terms and monohybrid pedigree analysis	Monohybrid inheritance and genetic diagrams	Covered except: the genetic pedigree diagram itself. Every term the board lists is defined and used, incomplete dominance included, and monohybrid crosses are laid out line by line -- but the family-tree convention is not here. The lesson section called "Reading a pedigree backwards" is a pea cross deduced from offspring ratios, not a pedigree, and the only other mention is a sex-linkage aside that assumes the reader can already read one. Squares, circles, shading, generation numbering and the deduction of a genotype from an unaffected couple with an affected child are absent.
2.14	How the cystic fibrosis mutation impairs three systems	Mutation, gene expression and cancer, Genome analysis, genetic screening and gene therapy	Covered except: the digestive and reproductive systems, and the mucus mechanism that connects all three. What is taught is the molecular fault -- a chloride channel that misfolds and never reaches the membrane -- and, in passing, that gene therapy targets airway epithelium. Why that fault thickens mucus, why thick mucus blocks a pancreatic duct or the vas deferens, and the consequences for digestion and fertility are not written.
2.15	Uses and implications of genetic screening	Genome analysis, genetic screening and gene therapy	Covered
2.16	Social and ethical issues of genetic screening	Genome analysis, genetic screening and gene therapy	Covered

3 Voice of the Genome

Ref	Specification heading	Taught in	Coverage
3.1	All organisms are made of cells with common features	Eukaryotic cell structure and organelles, Prokaryotic cells and viruses	Covered
3.2	Ultrastructure of eukaryotic cells	Eukaryotic cell structure and organelles, Optical microscopy and calibrated measurement	Covered
3.3	rER and Golgi in protein transport	Eukaryotic cell structure and organelles, Cofactors, coenzymes and where enzymes work	Covered
3.4	Ultrastructure of prokaryotic cells	Prokaryotic cells and viruses	Covered except: pili. Cell wall, capsule, plasmid, flagellum, ribosomes and circular DNA are all treated, and mesosomes are treated by being explained away as a fixation artefact, which is a better answer than the board's list expects. Pili are not mentioned at all, in this lesson or anywhere else, so a candidate asked to label one would have nothing.
3.5	Recognising organelles in electron micrographs	Eukaryotic cell structure and organelles, Microscopy, magnification and resolution, Optical microscopy and calibrated measurement	Covered
3.6	Specialisation of mammalian gametes	Gametes, fertilisation and early development	Covered
3.7	Fertilisation in mammals	Gametes, fertilisation and early development	Covered
3.8	Loci, linkage and sex linkage	Dihybrid inheritance, linkage, epistasis and the chi-squared test, Monohybrid inheritance and genetic diagrams	Covered
3.9	Meiosis and the sources of genetic variation	Meiosis and the sources of genetic variation	Covered
3.10	Mitosis and the cell cycle	The cell cycle and mitosis, Preparing biological material: squashes, sections and mounts	Covered
3.11	Stem cells, potency and their use in therapy	Stem cells and cell potency, Cell specialisation and biological organisation	Covered
3.12	Differential gene expression and the lac operon	Control of gene expression, Cell specialisation and biological organisation	Covered
3.13	Cells into tissues, organs and systems	Cell specialisation and biological organisation	Covered
3.14	Genotype, environment and epigenetic modification	Control of gene expression, Continuous and discontinuous variation	Covered
3.15	Polygenic inheritance and continuous variation	Continuous and discontinuous variation	Covered

4 Biodiversity and Natural Resources

Ref	Specification heading	Taught in	Coverage
4.1	The variety of life and the threat to it	Measuring biodiversity, The carbon cycle and climate change, Conservation in situ and ex situ	Covered
4.2	Biodiversity, endemism and the two indices	Measuring biodiversity	Covered except: the term endemism, and the heterozygosity index H. Species richness, species evenness and genetic diversity are all taught, and the index of diversity the board prints in sub-part iii) is Simpson's index, which the lesson works in both of the forms boards set. But endemism is never defined here -- the word 'endemic' appears in this library only in its epidemiological sense, which is a different meaning -- and the heterozygosity index, heterozygotes over individuals, is not given as a formula anywhere.
4.3	Niche and adaptation	Populations and their limits, Natural selection: variation, selection and allele frequency	Covered
4.4	Natural selection leading to adaptation and evolution	Natural selection: variation, selection and allele frequency, Evidence for evolution, resistance and genetic drift	Covered
4.5	Hardy-Weinberg and reproductive isolation	Population genetics and Hardy-Weinberg equilibrium, Speciation and reproductive isolation	Covered
4.6	Classification, the species concept and three domains	Classification, phylogeny and molecular evidence, The five kingdoms, species concepts and viruses	Covered
4.7	Ultrastructure of plant cells	Eukaryotic cell structure and organelles	Covered except: amyloplasts and the middle lamella. The wall, chloroplasts, the vacuole with its tonoplast named, plasmodesmata and pits are all treated and compared with animal cells, but amyloplasts appear nowhere in this library -- starch storage is taught as a molecule, never as an organelle -- and the middle lamella is named only in passing in two other lessons, not as a feature of a plant cell.
4.8	Recognising plant organelles in electron micrographs	Eukaryotic cell structure and organelles, Microscopy, magnification and resolution, Optical microscopy and calibrated measurement	Covered except: amyloplasts, and with them the ability to tell an amyloplast from a chloroplast in a micrograph, which is the recognition this statement is really testing. The middle lamella is likewise not something a reader of this library would be able to point to in an image.
4.9	Starch, cellulose and cellulose microfibrils	Carbohydrate structure and function	Covered
4.10	Microfibrils, secondary thickening and plant fibres	Carbohydrate structure and function, Xylem and the transpiration stream	Covered except: sclerenchyma fibres, and the human exploitation of plant fibres. Microfibril arrangement and tensile strength are taught, and lignified secondary thickening is taught properly for the xylem vessel -- rings, spirals and a pitted mesh, and why an unreinforced tube would collapse. Sclerenchyma is not named anywhere in this library, and nothing here says what people make from plant fibres or why the arrangement of the microfibrils is what makes rope, linen or sacking possible.
4.11	Sclerenchyma, xylem vessels and phloem compared	Xylem and the transpiration stream, Phloem translocation and the mass-flow hypothesis, Cell specialisation and biological organisation, Optical microscopy and calibrated measurement, Preparing biological material: squashes, sections and mounts	Covered except: sclerenchyma fibres, which is one of the three tissues the statement asks a candidate to compare. Xylem vessels and phloem are each taught in full -- structure, position in the stem and function, with sieve plates, companion cells and lignified vessel walls -- and can be identified in a section. The third column of the comparison is empty.
4.12	Water and inorganic ions in plants	Water and inorganic ions, Xylem and the transpiration stream, Nutrient cycles: nitrogen, phosphorus and eutrophication	Covered
4.13	The development of drug testing protocols	Diet, energy and how to read a health claim, Antibodies, vaccination and the four kinds of immunity, Mutation, gene expression and cancer	Covered except: William Withering's digitalis soup, the term double-blind, and three-phase testing. The randomised controlled trial and the placebo are both taught, with what randomisation is for and why a control group is not the same as a control variable. What is missing is the whole historical arc the statement is built on -- the move from an eighteenth-century physician titrating a herbal preparation to a modern protocol -- and the phase I, II and III structure by name.
4.14	Conditions required for bacterial growth	Industrial biotechnology and fermentation, Populations and their limits, Prokaryotic cells and viruses, Aseptic technique and the effect of antimicrobials	Covered
4.15	Plant fibres and starch for sustainability		Nothing here teaches this: Nothing here addresses plant-based products replacing oil-based plastics, or the sustainability case for using plant fibres and starch as materials. Starch is taught as a storage polysaccharide and cellulose as a structural one, and the library stops there: materials science from plants is a Salters-Nuffield context with no counterpart in the biology the other three mapped boards ask for, so nothing was ever written towards it. It is the natural companion to 4.10 and would be written with it.
4.16	Evaluating zoos and seed banks in conservation	Conservation in situ and ex situ	Covered

5 On the Wild Side (A-level only)

Ref	Specification heading	Taught in	Coverage
5.1	Ecosystem, community, population and habitat	Populations and their limits	Covered
5.2	Biotic and abiotic control of numbers and distribution	Populations and their limits, Succession and environmental change, Field sampling, distribution and behavioural response	Covered
5.3	Niche, distribution and abundance	Populations and their limits, Field sampling, distribution and behavioural response	Covered
5.4	Succession from colonisation to climax	Succession and environmental change, Field sampling, distribution and behavioural response	Covered
5.5	The overall reaction of photosynthesis	Chloroplast structure and the light-dependent reactions, The Calvin cycle	Covered
5.6	ADP phosphorylation and ATP hydrolysis	Glycolysis, ATP and the link reaction, The Krebs cycle and oxidative phosphorylation	Covered
5.7	The light-dependent reactions	Chloroplast structure and the light-dependent reactions, Chromatography and the separation of pigments, Measuring respiration and photosynthesis rates	Covered
5.8	The light-independent reactions and their products	The Calvin cycle, Measuring respiration and photosynthesis rates	Covered except: the abbreviation GALP, and nucleic acids among the uses of the sugars. This library prints the same molecule as TP, triose phosphate, throughout, and never gives the board's form, glyceraldehyde 3-phosphate, so a candidate meeting GALP in a question would not recognise it. Sub-part ii)'s list of what the sugars become is served for polysaccharides, amino acids and lipids -- the lesson works each of those out of TP or GP explicitly -- but not for nucleic acids.
5.9	Chloroplast structure and photosynthesis	Chloroplast structure and the light-dependent reactions	Covered
5.10	Gross and net primary productivity	Limiting factors and primary productivity	Covered
5.11	Efficiency of biomass and energy transfer	Limiting factors and primary productivity	Covered
5.12	Evidence for climate change and its causes	The carbon cycle and climate change	Covered except: pollen preserved in peat bogs and dendrochronology, which are two of the four lines of evidence the board names. The carbon dioxide record is taught properly, including the annual wobble and what causes it, and the temperature record appears as data inside a worked example -- but it is used there as a cause of a distribution shift rather than presented as evidence that the climate has changed, and the two proxy records are absent entirely.
5.13	Anthropogenic causes and the greenhouse effect	The carbon cycle and climate change	Covered
5.14	Extrapolation and models of future climate change	Handling data: units, scales, rates and uncertainty, Variables and controls: what an experiment can show, The carbon cycle and climate change	Covered except: climate models and their limitations. Extrapolation as a technique is taught, along with what it does and does not license, but no lesson describes a climate model, what goes into one, why different models disagree, or why their projections are given as ranges. Sub-part ii) asks for the limitations specifically and there is nothing here to draw them from.
5.15	Effects of climate change on plants and animals	The carbon cycle and climate change	Covered except: changing rainfall patterns. Distribution is taught with the tolerance argument and worked on a real range shift, and the effect on development and life cycles is taught as a timing mismatch between a bird's calendar and its prey's -- both of the outcomes the board names. The driver taught throughout is temperature; rainfall, and changes in its pattern, are not discussed as a cause of any of it.
5.16	Temperature, enzyme rate and its impact on organisms	Factors affecting enzyme rate: temperature, pH and concentration, Thermoregulation in endotherms and ectotherms, The carbon cycle and climate change, Measuring the rate of an enzyme-controlled reaction	Covered
5.17	Evolution as a change in allele frequency	Natural selection: variation, selection and allele frequency, Evidence for evolution, resistance and genetic drift, Population genetics and Hardy-Weinberg equilibrium	Covered
5.18	The scientific community validating new evidence	Evidence for evolution, resistance and genetic drift, Genome analysis, genetic screening and gene therapy, Classification, phylogeny and molecular evidence	Covered except: scientific journals, the peer review process and scientific conferences. The evidence itself is taught -- four independent lines for common ancestry, molecular phylogeny reading relatedness out of sequences, and genome sequencing with what it yields -- and so is the fact that the theory was assembled by identifiable people who could not explain everything. The machinery of validation the statement names, the three institutions by which a claim becomes accepted, is not described anywhere in this library.
5.19	Isolation, gene flow and speciation	Speciation and reproductive isolation	Covered
5.20	Why conclusions can depend on who reaches them	Cholesterol, atheroma and what a risk factor means, Diet, energy and how to read a health claim, Variables and controls: what an experiment can show	Covered
5.21	The carbon cycle applied to reducing atmospheric CO2	The carbon cycle and climate change	Covered except: the methods themselves. Every store and every transfer is taught, and so is the arithmetic that shows which arrow was made bigger -- so a reader has the knowledge the statement says to apply. What is not written is the application: no lesson discusses reducing emissions, changing land use to increase uptake, or any other method of lowering the atmospheric concentration.
5.22	Reforestation and sustainable resources	Managing ecosystems sustainably, Conservation in situ and ex situ, The carbon cycle and climate change	Covered except: reforestation and biofuels, which are the board's two named examples. The conflict between human needs and conservation is taught in full and with numbers -- sustainable yield read off a curve, timber taken without losing the wood, fisheries where the rules do the work, and who decides -- and deforestation is treated as a carbon transfer. Planting forests back, and growing fuel rather than food, are not.

6 Immunity, Infection and Forensics (A-level only)

Ref	Specification heading	Taught in	Coverage
6.1	Determining the time of death of a mammal	The carbon cycle and climate change, Succession and environmental change, Muscles and movement: the sliding-filament model	Covered except: forensic entomology, body temperature, and the forensic application itself. Decomposition is taught as a carbon transfer carried out by named organisms, succession is taught in full, and muscle contraction and relaxation are taught to the molecule -- so three of the board's five lines of evidence exist here as biology. None of them is ever pointed at a body. Insect succession on a corpse, the cooling curve and rigor mortis are absent, and so is the reasoning that turns any of this into an estimate of a time.
6.2	Micro-organisms in decomposition and the carbon cycle	The carbon cycle and climate change, Nutrient cycles: nitrogen, phosphorus and eutrophication	Covered
6.3	DNA profiling for identity and relationship	Genome analysis, genetic screening and gene therapy, Recombinant DNA technology, Extracting and precipitating DNA from tissue	Covered
6.4	The polymerase chain reaction	Recombinant DNA technology, Extracting and precipitating DNA from tissue	Covered
6.5	Bacteria and viruses compared	Prokaryotic cells and viruses	Covered
6.6	How TB and HIV infect human cells	Infectious disease: transmission and control, Pathogens and non-specific defences, Prokaryotic cells and viruses	Covered
6.7	Non-specific responses to infection	Pathogens and non-specific defences	Covered except: interferon. Inflammation, lysozyme action and phagocytosis are all taught -- phagocytosis stage by stage, including the antigen-presenting step most answers omit -- but interferon is not named anywhere in this library, and nothing here describes an antiviral protein released by an infected cell to protect its neighbours.
6.8	Antigens, antibodies and the immune response	The specific immune response, Antibodies, vaccination and the four kinds of immunity, Pathogens and non-specific defences	Covered
6.9	B cells and T cells in the immune response	The specific immune response	Covered
6.10	One gene giving more than one protein	The genetic code and transcription, Control of gene expression	Covered
6.11	Routes of entry and the body's barriers	Pathogens and non-specific defences, Infectious disease: transmission and control	Covered
6.12	Natural, artificial, active and passive immunity	Antibodies, vaccination and the four kinds of immunity	Covered
6.13	The evolutionary race between pathogens and hosts	Antibodies, vaccination and the four kinds of immunity, Infectious disease: transmission and control, Evidence for evolution, resistance and genetic drift	Covered except: the 'evolutionary race' framing, and evasion mechanisms presented as the evidence for it. Antigenic variation is taught properly -- why the influenza vaccine changes and the measles one does not -- and HIV's behaviour is described, so two evasion mechanisms exist here as facts. What is not here is the argument the statement asks a candidate to make: that these mechanisms are what an arms race between two evolving populations looks like, with selection acting on both sides at once.
6.14	Bacteriostatic and bactericidal antibiotics	Evidence for evolution, resistance and genetic drift, Aseptic technique and the effect of antimicrobials	Covered except: both terms, and the contrast between them. The definition of an antibiotic given here is a substance that 'kills or inhibits the growth of bacteria', so the distinction is present in substance inside a single clause -- but neither word is printed anywhere in this library, no example is given of either class, and nothing says why the difference matters clinically, which is what a question would ask.
6.15	Hospital acquired infections and codes of practice	Evidence for evolution, resistance and genetic drift	Covered except: hospital acquired infection as a subject, and the hospital codes of practice. The prescribing half is genuinely served: why resistance frequencies fall when antibiotic use falls, why the prescribed course is finished, and the 2017 qualification that unnecessarily long courses do their own harm. MRSA is named and its mechanism given. But nothing explains why hospitals in particular concentrate resistant organisms, and infection prevention and control -- hand hygiene, isolation, screening on admission, cleaning protocols -- is not written anywhere.

7 Run for your Life (A-level only)

Ref	Specification heading	Taught in	Coverage
7.1	Muscles, tendons, skeleton and ligaments in movement	Muscles and movement: the sliding-filament model, Gas exchange in mammals: lungs and ventilation	Covered except: tendons, ligaments and the skeleton as a lever system, and the terms extensor and flexor. Antagonistic pairs are taught, and taught twice: the external and internal intercostals are worked as a pair in the breathing lesson, and the muscles lesson explains that a muscle can pull and cannot push and so must be lengthened by its antagonistic partner. What is absent is everything between the muscle and the bone -- what a tendon is, what a ligament is, how a joint acts as a lever, and which member of a pair is the extensor.
7.2	Sliding filament contraction of skeletal muscle	Muscles and movement: the sliding-filament model	Covered
7.3	The overall reaction of aerobic respiration	Glycolysis, ATP and the link reaction, The Krebs cycle and oxidative phosphorylation, Measuring respiration and photosynthesis rates	Covered
7.4	Glycolysis in aerobic and anaerobic respiration	Glycolysis, ATP and the link reaction, Anaerobic respiration and the respiratory quotient	Covered
7.5	The link reaction and the Krebs cycle	Glycolysis, ATP and the link reaction, The Krebs cycle and oxidative phosphorylation	Covered
7.6	Oxidative phosphorylation and chemiosmosis	The Krebs cycle and oxidative phosphorylation	Covered
7.7	The fate of lactate	Anaerobic respiration and the respiratory quotient	Covered
7.8	Myogenic cardiac muscle, conduction and the ECG	The heart and cardiac cycle	Covered
7.9	Cardiac output, ventilation and their control	The heart and cardiac cycle, Gas exchange in mammals: lungs and ventilation, Organisation of the nervous system	Covered except: how ventilation rate is controlled. Cardiac output is calculated, and heart-rate control is worked in full through chemoreceptors, pressure receptors and the cardiovascular centre in the medulla. The ventilation centre is named as a medullary centre that sets breathing rhythm, in one sentence, and that is all: the chemoreceptor loop that raises breathing rate during exercise, and the detection of carbon dioxide that drives it, are not written.
7.10	Muscle fibre structure and the two fibre types	Muscles and movement: the sliding-filament model	Covered
7.11	Negative and positive feedback	Hormonal communication and negative feedback	Covered
7.12	Homeostasis and thermoregulation during exercise	Thermoregulation in endotherms and ectotherms, Hormonal communication and negative feedback, Organisation of the nervous system	Covered
7.13	The consequences of too much and too little exercise	Cholesterol, atheroma and what a risk factor means, Diet, energy and how to read a health claim, Regulation of blood glucose and diabetes mellitus, Variables and controls: what an experiment can show	Covered except: the disadvantages of exercising too much. Inactivity is treated properly as a risk factor for obesity, cardiovascular disease and type 2 diabetes, and the correlation-and-causation reasoning the statement asks for is the scientific-method unit's subject. The other half is empty: wear on joints, and suppression of the immune system after heavy training, are not discussed anywhere.
7.14	Medical technology in sport: keyhole surgery and prostheses		Nothing here teaches this: Nothing here discusses keyhole surgery, prostheses, or how medical technology lets people with injuries and disabilities take part in sport. This is applied medicine rather than biology, and no other mapped board asks for it, so nothing was written towards it.
7.15	Ethics of performance-enhancing substances		Nothing here teaches this: Nothing here discusses performance-enhancing substances at all, let alone the ethical positions on their use. The library's treatment of drugs is pharmacological -- where a drug acts on a synapse, how a statin works -- and never reaches sport. Along with 7.14 this is the pair that makes Topic 7 the second most gapped topic in this ledger.
7.16	Genes switched by transcription factors and hormones	Control of gene expression, Hormonal communication and negative feedback	Covered

8 Grey Matter (A-level only)

Ref	Specification heading	Taught in	Coverage
8.1	Sensory, relay and motor neurones, and myelination	Organisation of the nervous system, The action potential and its propagation	Covered
8.2	Effectors responding to a stimulus, and the pupil	Receptors: transduction and the reflex arc, Organisation of the nervous system	Covered except: how the pupil dilates and contracts. Sub-part i) is served in full -- stimulus, receptor, coordinator, effector, response, with the reflex arc worked and the pupil reflex named in passing as an example of one. Sub-part ii) is not: the radial and circular muscles of the iris, their antagonistic action, and which one contracts in bright light are not written. The iris appears in this library only as an example of where involuntary muscle is found.
8.3	Conduction of the action potential	The action potential and its propagation	Covered
8.4	Synapses and neurotransmitters	The synapse: transmission, and why it runs one way	Covered
8.5	Rods, rhodopsin and generating an optic-nerve impulse	Receptors: transduction and the reflex arc	Covered except: opsin and retinal as the two parts rhodopsin splits into, the cation channels, and the hyperpolarisation of the rod. Rods are taught well -- rhodopsin bleached by little light, the resynthesis behind dark adaptation, convergence and summation, and rods against cones on sensitivity and acuity -- but the transduction mechanism the statement asks for is not there. This library says the generator potential arises and does not say how, and the counter-intuitive part, that a rod hyperpolarises in light rather than depolarising, is the part Salters-Nuffield sets questions on.
8.6	Phytochrome and IAA in plant responses	Plant responses: tropisms, auxins and the classic experiments, Control of gene expression, Transpiration and stomatal control	Covered except: phytochrome, and the effect of either substance on transcription. IAA is named in the board's own form, made in the shoot tip, transported away from it and sideways by carrier proteins, with the classic tropism experiments and apical dominance -- but the mechanism taught for it is acid growth in the cell wall, not gene expression, and the statement asks for transcription specifically. Phytochrome is absent entirely: nothing here covers the red and far-red forms or the photoperiodic responses they control.
8.7	Nervous and hormonal coordination	Hormonal communication and negative feedback, Organisation of the nervous system	Covered
8.8	Regions of the human brain	Organisation of the nervous system	Covered
8.9	MRI, fMRI, PET and CT in brain investigation		Nothing here teaches this: No medical imaging technique is described anywhere in this library. Nothing here says what any of the four detects, what the difference is between a structural and a functional scan, or what each has shown about the brain. This is one of five consecutive Grey Matter statements with nothing behind them, 8.9 to 8.13, and together they are the largest single block of uncovered specification in this ledger.
8.10	The critical period in visual development		Nothing here teaches this: Nothing here covers the critical period, or the development of visual capacity after birth at all. The library teaches how a rod works and how the nervous system is wired; it does not teach how that wiring is established by experience or what happens when the experience is withheld.
8.11	Animal models in brain research		Nothing here teaches this: Neither the role of animal models in understanding human brain development nor Hubel and Wiesel's experiments with monkeys and kittens appear anywhere. This depends on 8.10, since the experiments are what established the critical period, so the two would have to be written together.
8.12	Ethics of using animals in medical research		Nothing here teaches this: Nothing here argues the case for or against animals in medical research, and nothing sets out two ethical standpoints to argue it from. Eight lessons carry ethical argument, and the nearest of them -- the welfare and regulatory argument about transgenic animals used to make medicines -- is about production rather than research, and does not name the frameworks the statement asks a candidate to reason within. Pairs with 1.17: the specification opens and closes on the ethics of using animals, and this library answers neither.
8.13	Learning by habituation		Nothing here teaches this: Habituation is not defined, described or exemplified anywhere. No lesson treats learning of any kind. CP18 asks a student to investigate it, so the practical has nothing behind it here either.
8.14	Brain chemical imbalances and new drugs	The synapse: transmission, and why it runs one way, Stem cells and cell potency	Covered except: serotonin and its relation to depression. Dopamine is named as a neurotransmitter, cocaine's effect on its reuptake is worked, and dopamine-secreting neurones for Parkinson's disease are given as a stem-cell proposal -- so the board's first named example is served at least in outline. Serotonin is not mentioned anywhere in this library, and neither is depression.
8.15	Drugs acting on synaptic transmission	The synapse: transmission, and why it runs one way	Concept covered; the board's example is not: L-Dopa and MDMA, which are the board's two required examples. The concept is taught thoroughly and with more worked cases than the statement asks for: a table of five drugs, each placed at the point in the sequence where it acts -- nicotine, organophosphates, curare, cocaine and botulinum toxin -- and an explicit instruction that questions supply an unfamiliar substance and expect it to be reasoned about from the sequence.
8.16	Genome sequencing and personalised medicine	Genome analysis, genetic screening and gene therapy	Covered
8.17	Drugs produced using genetically modified organisms	Pharming, recombinant medicines and synthetic biology, Recombinant DNA technology, Industrial biotechnology and fermentation	Covered except: genetically modified plants as a source of medicines. Microorganisms are covered in full -- recombinant insulin and the fermenter that grows it -- and animals are the pharming lesson's main subject, with antithrombin from transgenic goats worked through the mammary-specific promoter. Plant-made pharmaceuticals, the third of the board's three, are not discussed.
8.18	Risks and benefits of genetically modified organisms	Recombinant DNA technology, Pharming, recombinant medicines and synthetic biology, Cloning in plants and animals	Covered
8.19	Investigating nature and nurture in brain development	Continuous and discontinuous variation	Covered except: the abilities of new-born babies, animal experiments, studies of people with damaged brain areas, and cross-cultural studies -- four of the board's five methods. Twin studies are the one that is taught, and taught as a design rather than named: identical twins reared apart differ only environmentally, non-identical twins reared together mainly genetically. Nothing here applies any method to brain development specifically.

Biology B 8BI0/9BI0

The conventionally ordered route. A row here is one roman-numeral statement together with the sub-topic it sits under, because the romans restart inside every sub-topic and neither part identifies a statement on its own; a map keyed on the sub-topic alone would report a heading as taught when one of the statements under it was not. The short label on each row is the board's own sub-topic heading, kept as a signpost. The check was made on 21 August 2026, against the specification, Issue 4 (November 2018).

1 Biological Molecules

Ref	Specification heading	Taught in	Coverage
1.1 i	Carbohydrates	Carbohydrate structure and function	Covered
1.1 ii	Carbohydrates	Carbohydrate structure and function	Covered
1.1 iii	Carbohydrates	Carbohydrate structure and function, Digestion and absorption in the human gut, Qualitative biochemical tests, and what they do not tell you	Covered
1.1 iv	Carbohydrates	Carbohydrate structure and function	Covered
1.2 i	Lipids	Lipids: triglycerides, phospholipids and ester bonds	Covered
1.2 ii	Lipids	Lipids: triglycerides, phospholipids and ester bonds	Covered
1.2 iii	Lipids	Lipids: triglycerides, phospholipids and ester bonds	Covered except: Waterproofing is not taught as a role a lipid's structure fits it for. Energy storage is covered in full, roughly twice the energy per gram from a highly reduced hydrocarbon tail plus insolubility so the store does not affect water potential, and thermal insulation by adipose tissue is covered with protection alongside it. Waxes are named as lipids in passing and the waterproof cuticle of an insect and of a leaf appear in the gas exchange lessons, but nothing joins the two: no lesson says that being non-polar is what makes a lipid a waterproofing layer.
1.2 iv	Lipids	Lipids: triglycerides, phospholipids and ester bonds, Membrane structure and the fluid mosaic model	Covered
1.3 i	Proteins	Protein structure and function	Covered
1.3 ii	Proteins	Protein structure and function	Covered
1.3 iii	Proteins	Protein structure and function	Covered
1.3 iv	Proteins	Protein structure and function	Covered
1.3 v	Proteins	Protein structure and function	Covered
1.4 i	DNA and protein synthesis	DNA and RNA structure	Covered
1.4 ii	DNA and protein synthesis	DNA replication	Covered
1.4 iii	DNA and protein synthesis	The genetic code and transcription	Covered
1.4 iv	DNA and protein synthesis	DNA and RNA structure, Translation and protein synthesis	Covered
1.4 v	DNA and protein synthesis	DNA and RNA structure, Translation and protein synthesis	Covered
1.4 vi	DNA and protein synthesis	The genetic code and transcription, Translation and protein synthesis	Covered
1.4 vii	DNA and protein synthesis	The genetic code and transcription	Covered
1.4 viii	DNA and protein synthesis	Mutation, gene expression and cancer, DNA replication	Covered
1.4 ix	DNA and protein synthesis	DNA replication, Monohybrid inheritance and genetic diagrams	Covered
1.5 i	Enzymes	Enzyme action and specificity, Protein structure and function	Covered
1.5 ii	Enzymes	Enzyme action and specificity	Covered
1.5 iii	Enzymes	Enzyme action and specificity	Covered
1.5 iv	Enzymes	Factors affecting enzyme rate: temperature, pH and concentration, Measuring the rate of an enzyme-controlled reaction	Covered
1.5 v	Enzymes	Factors affecting enzyme rate: temperature, pH and concentration, Measuring the rate of an enzyme-controlled reaction	Covered
1.5 vi	Enzymes	Enzyme inhibition and metabolic control	Covered
1.5 vii	Enzymes	Cofactors, coenzymes and where enzymes work, Digestion and absorption in the human gut	Covered
1.6 i	Inorganic ions	Water and inorganic ions, Xylem and the transpiration stream	Covered
1.7 i	Water	Water and inorganic ions	Covered except: Incompressibility is not taught. Four of the board's five properties are derived from hydrogen bonding and given a named biological consequence: high specific heat capacity and the slow temperature change of a cell or a lake, water as a polar solvent with the exception of lipids made explicit, surface tension supporting a pond skater, and maximum density at 4 degrees Celsius with ice floating and insulating the water beneath. Nothing says that water resists being compressed, and neither of the consequences that usually carries, turgor holding a herbaceous plant up and the hydrostatic skeleton of a soft-bodied animal, is presented as a property of the liquid.

2 Cells, Viruses and Reproduction of Living Things

Ref	Specification heading	Taught in	Coverage
2.1 i	Eukaryotic and prokaryotic cell structure and function		Nothing here teaches this: Cell theory is not stated anywhere in this library. Cells are treated throughout as the unit of structure and function, and prokaryotic, eukaryotic and viral organisation are compared in detail, so a student meets everything the theory generalises; but no lesson names cell theory, and none presents it as the unifying concept this statement asks for. Nothing was written here because the library was built from the organelle outwards rather than from the doctrine inwards, and no board mapped before today required the doctrine by name.
2.1 ii	Eukaryotic and prokaryotic cell structure and function	Cell specialisation and biological organisation	Covered
2.1 iii	Eukaryotic and prokaryotic cell structure and function	Prokaryotic cells and viruses, Eukaryotic cell structure and organelles	Covered
2.1 iv	Eukaryotic and prokaryotic cell structure and function		Nothing here teaches this: Gram positive and Gram negative cell walls are not taught. The bacterial wall is taught as murein and its cross-linking is the mechanism penicillin is explained through, so the chemistry the distinction rests on is present; but the two wall architectures, the stain that separates them and the reason each responds differently to particular antibiotics are all absent. Nothing was written because the three boards mapped before this one teach the wall without the stain, and Biology B is the first to ask for it.
2.1 v	Eukaryotic and prokaryotic cell structure and function	Eukaryotic cell structure and organelles	Covered
2.1 vi	Eukaryotic and prokaryotic cell structure and function	Microscopy, magnification and resolution, Optical microscopy and calibrated measurement	Covered
2.1 vii	Eukaryotic and prokaryotic cell structure and function	Microscopy, magnification and resolution, Plan diagrams and tissue sections, The cell cycle and mitosis, Optical microscopy and calibrated measurement, Preparing biological material: squashes, sections and mounts	Covered
2.2 i	Viruses	The five kingdoms, species concepts and viruses, Prokaryotic cells and viruses	Covered except: Two of the board's four named viruses are missing: lambda phage as the DNA example and Ebola as an RNA one. The classification itself is taught in full, DNA or RNA first and then double- or single-stranded, with all four boxes occupied and the consequence that RNA genomes mutate fastest; tobacco mosaic virus is named as a single-stranded RNA plant virus and HIV is worked through layer by layer as an RNA retrovirus carrying reverse transcriptase. What is absent is two exemplars rather than the scheme.
2.2 ii	Viruses		Nothing here teaches this: The lytic cycle and latency are not taught. Viral replication appears only as an outcome, hundreds of particles assembled from the host's ribosomes and nucleotides and the cell either burst or budded through, and HIV's reverse transcription and integration into a host chromosome are described; but no lesson names the lytic cycle or takes it stage by stage, and nothing describes a latent phase or what ends it. Nothing was written because the mapped boards examine viral structure and pathogenicity rather than the phage life cycle.
2.2 iii	Viruses	The five kingdoms, species concepts and viruses, Prokaryotic cells and viruses	Covered except: The conclusion this statement draws is never drawn. That a virus is acellular is taught thoroughly, with no cytoplasm, no ribosomes, no organelles and no metabolism of its own, and antiviral drugs are mentioned as being defeated within a course of treatment because RNA genomes mutate fast. What is missing is the inference between the two: nothing says that because there is no metabolism to poison, an antiviral has to act on the replication cycle, and no stage of that cycle is named as a drug target.
2.2 iv	Viruses	Infectious disease: transmission and control	Concept covered; the board's example is not: The 2014 Ebola outbreak in West Africa, which is the board's named illustration.
2.2 v	Viruses	Antibodies, vaccination and the four kinds of immunity	Covered except: The ethics of untested drugs is not the case the library argues. Vaccine trial ethics are set out on both sides, testing on animals before humans, consent, who bears the risk, trials run where the disease is and therefore often in poorer countries, and a placebo group deliberately left unprotected during an epidemic. That last argument is the closest the library comes and it is genuinely close; but offering a drug that has not completed trials to people who will otherwise die, and the balance of hope against harm and evidence that goes with it, is not discussed.
2.3 i	Eukaryotic cell cycle and division	The cell cycle and mitosis	Covered
2.3 ii	Eukaryotic cell cycle and division	The cell cycle and mitosis, Preparing biological material: squashes, sections and mounts	Covered
2.3 iii	Eukaryotic cell cycle and division	The cell cycle and mitosis, Cloning in plants and animals, Preparing biological material: squashes, sections and mounts	Covered
2.3 iv	Eukaryotic cell cycle and division	Meiosis and the sources of genetic variation	Covered
2.3 v	Eukaryotic cell cycle and division	Meiosis and the sources of genetic variation	Covered
2.3 vi	Eukaryotic cell cycle and division	Mutation, gene expression and cancer	Covered except: Chromosome mutations are not separated from gene mutations as a class. Translocation is present as one row of the mutation table, defined as a section moving to a different chromosome with genes at both break points liable to be disrupted or newly switched on, and inversion and duplication sit beside it; but nothing distinguishes a change to the structure of a whole chromosome from a change to a base sequence, and the reciprocal exchange, the balanced carrier who is unaffected, and the unbalanced gamete that follows are all absent.
2.3 vii	Eukaryotic cell cycle and division	Meiosis and the sources of genetic variation	Covered except: Monosomy and Turner's syndrome are absent. Non-disjunction is taught properly, at anaphase I affecting all four products and at anaphase II affecting two, with the gamete counts each produces and trisomy 21 named as the origin of Down syndrome; so the polysomy half of the statement is fully served. The gamete that is one chromosome short is described in the arithmetic but never followed to a named condition, and Turner's syndrome does not appear anywhere in the library.
2.4 i	Sexual reproduction in mammals	Gametes, fertilisation and early development	Covered
2.4 ii	Sexual reproduction in mammals	Gametes, fertilisation and early development	Covered
2.4 iii	Sexual reproduction in mammals	Gametes, fertilisation and early development	Covered
2.5 i	Sexual reproduction in plants		Nothing here teaches this: Sexual reproduction in flowering plants was never written. Nothing in this library describes the anther, the formation of a pollen grain in it, or the development of an embryo sac in the ovule. The meiosis lesson goes as far as saying that the four products of a pollen mother cell in an anther often stay together as a group of four, and that is the whole of it. The library's plant content was built around transport, responses and photosynthesis, and reproduction in plants was left out of the plan rather than attempted and cut.
2.5 ii	Sexual reproduction in plants		Nothing here teaches this: Nothing covers the growth of a pollen tube down the style, the tube nucleus that directs it, the generative nucleus dividing to give two male nuclei, or the enzymes that digest a path ahead. The pollen tube is named once in the whole library, as an example of chemotropism in the plant-responses lesson. Core practical 4, the effect of sucrose concentration on pollen tube growth or germination, also has no counterpart among this library's fourteen practical capabilities, so this is a gap in the practical list as well as in the content.
2.5 iii	Sexual reproduction in plants		Nothing here teaches this: Double fertilisation is absent, and with it the triploid endosperm and the zygote formed alongside it. The endosperm is named once, in the gibberellin and germinating barley section of the plant-responses lesson, as the starch store the aleurone layer surrounds; nothing says where it came from or that it carries three sets of chromosomes. Written without 2.5 i and ii in place, this statement would have nothing to stand on.

3 Classification and Biodiversity

Ref	Specification heading	Taught in	Coverage
3.1 i	Classification	Classification, phylogeny and molecular evidence	Covered
3.1 ii	Classification	Classification, phylogeny and molecular evidence, The five kingdoms, species concepts and viruses, Speciation and reproductive isolation	Covered
3.1 iii	Classification	The five kingdoms, species concepts and viruses, Speciation and reproductive isolation, Classification, phylogeny and molecular evidence	Covered
3.1 iv	Classification	Recombinant DNA technology, Classification, phylogeny and molecular evidence	Covered except: Gel electrophoresis is never turned on the question this statement asks. The technique is taught in full, with the charge on every phosphate group, migration towards the positive electrode and short fragments travelling furthest through the gel mesh, and it is applied to DNA profiling of individuals. Comparing band patterns between species, and reading an evolutionary relationship out of how similar two patterns are, is not taught; the classification lesson reaches relatedness through sequence comparison, DNA hybridisation, amino acid counts and immunological precipitation instead.
3.1 v	Classification	Classification, phylogeny and molecular evidence, Genome analysis, genetic screening and gene therapy	Covered
3.1 vi	Classification		Nothing here teaches this: Peer review is not taught anywhere in this library. No lesson says what a scientific journal is, what happens to a paper before it appears in one, or what a conference is for, and no lesson uses any of them to explain how the evidence for evolution came to be accepted. What is taught instead is the evidence itself and how to weigh it: four independent lines that agree, the argument from correlation to cause, and the history of Darwin and Wallace including the joint reading of 1858, which is a validation event described without being named as one. The gap is the social machinery rather than the reasoning, and 10.4 iv asks for the same thing again.
3.1 vii	Classification	Classification, phylogeny and molecular evidence, The five kingdoms, species concepts and viruses	Covered
3.2 i	Natural selection	Natural selection: variation, selection and allele frequency	Covered
3.2 ii	Natural selection	Populations and their limits, Natural selection: variation, selection and allele frequency	Covered
3.2 iii	Natural selection	Speciation and reproductive isolation	Covered
3.2 iv	Natural selection	Evidence for evolution, resistance and genetic drift, Infectious disease: transmission and control	Covered
3.3 i	Biodiversity	Measuring biodiversity, Field sampling, distribution and behavioural response	Covered
3.3 ii	Biodiversity	Conservation in situ and ex situ, Measuring biodiversity	Covered
3.3 iii	Biodiversity	Conservation in situ and ex situ	Covered

4 Exchange and Transport

Ref	Specification heading	Taught in	Coverage
4.1 i	Surface area to volume ratio	Surface area to volume ratio: why size limits diffusion, Non-living models of diffusion, osmosis and surface area	Covered
4.1 ii	Surface area to volume ratio	Surface area to volume ratio: why size limits diffusion, The heart and cardiac cycle	Covered
4.2 i	Cell transport mechanisms	Membrane structure and the fluid mosaic model	Covered
4.2 ii	Cell transport mechanisms	Diffusion and osmosis	Covered
4.2 iii	Cell transport mechanisms	Membrane structure and the fluid mosaic model, Diffusion and osmosis	Covered
4.2 iv	Cell transport mechanisms	Active transport, co-transport and bulk transport, Membrane structure and the fluid mosaic model, Diffusion and osmosis, Investigating membrane permeability, Water relations of plant tissue: osmosis and transpiration	Covered
4.2 v	Cell transport mechanisms	Active transport, co-transport and bulk transport	Covered
4.2 vi	Cell transport mechanisms	Glycolysis, ATP and the link reaction	Covered
4.3 i	Gas exchange	Gas exchange in mammals: lungs and ventilation, Gas exchange in insects, fish and plants, Surface area to volume ratio: why size limits diffusion, Dissection and biological drawing	Covered
4.3 ii	Gas exchange	Gas exchange in insects, fish and plants, Transpiration and stomatal control	Covered except: Lenticels are not taught, and are not named anywhere in the library. Stomata are covered in full, including the potassium ion mechanism by which a guard cell opens one and the thickened inner wall that makes it bow, and the gas exchange surface in the leaf is correctly placed on the wet walls of the spongy mesophyll cells with the air spaces between them. What is missing is the third of the board's three routes: the pores in the bark of a woody stem through which a plant exchanges gas where it has no stomata at all.
4.4 i	Circulation	The heart and cardiac cycle, Blood vessels, tissue fluid and lymph, Dissection and biological drawing	Covered
4.4 ii	Circulation	The heart and cardiac cycle	Covered
4.4 iii	Circulation	The heart and cardiac cycle	Covered
4.4 iv	Circulation	The heart and cardiac cycle, Organisation of the nervous system	Covered
4.4 v	Circulation	The heart and cardiac cycle	Covered
4.4 vi	Circulation	Plan diagrams and tissue sections, Blood vessels, tissue fluid and lymph, Preparing biological material: squashes, sections and mounts	Covered except: Eosinophils are missing from the roster. Plasma and its proteins are taught, and erythrocytes, neutrophils, lymphocytes and monocytes are each described and identified on a stained blood smear by size and by nucleus, which is more than the statement asks for the four it covers. The board names a fifth cell and this library never introduces it, so a student working from here would meet the word for the first time in the examination.
4.4 vii	Circulation	Blood vessels, tissue fluid and lymph, Haemoglobin and oxygen dissociation curves, The specific immune response	Covered
4.4 viii	Circulation	Cholesterol, atheroma and what a risk factor means	Covered
4.4 ix	Circulation	Cholesterol, atheroma and what a risk factor means, Diet, energy and how to read a health claim	Covered
4.5 i	Transport of gases in the blood	Haemoglobin and oxygen dissociation curves	Covered
4.5 ii	Transport of gases in the blood	Haemoglobin and oxygen dissociation curves	Covered
4.5 iii	Transport of gases in the blood	Haemoglobin and oxygen dissociation curves, Muscles and movement: the sliding-filament model	Covered except: Myoglobin is never compared with haemoglobin. It appears twice in the library, as an oxygen store inside slow twitch muscle fibres and as part of why a diving seal manages on one lungful, so a student knows it exists and roughly what it is for. Absent are everything this statement actually asks: one polypeptide and one haem group against four of each, a hyperbolic curve lying far to the left of haemoglobin's, the much higher affinity that puts it there, and the very low partial pressure at which it finally gives its oxygen up, which is what makes it a store rather than a transporter.
4.5 iv	Transport of gases in the blood	Haemoglobin and oxygen dissociation curves	Covered
4.6 i	Transfer of materials between the circulatory system and cells	Blood vessels, tissue fluid and lymph	Covered
4.6 ii	Transfer of materials between the circulatory system and cells	Blood vessels, tissue fluid and lymph	Covered
4.7 i	Transport in plants	Cell specialisation and biological organisation, Xylem and the transpiration stream, Phloem translocation and the mass-flow hypothesis, Preparing biological material: squashes, sections and mounts	Covered
4.7 ii	Transport in plants	Xylem and the transpiration stream	Covered
4.7 iii	Transport in plants	Xylem and the transpiration stream	Covered
4.7 iv	Transport in plants	Transpiration and stomatal control, Water relations of plant tissue: osmosis and transpiration	Covered
4.7 v	Transport in plants	Phloem translocation and the mass-flow hypothesis	Covered

5 Energy for Biological Processes

Ref	Specification heading	Taught in	Coverage
5.1 i	Aerobic respiration	Glycolysis, ATP and the link reaction, Thermoregulation in endotherms and ectotherms	Covered
5.1 ii	Aerobic respiration	Glycolysis, ATP and the link reaction, The Krebs cycle and oxidative phosphorylation	Covered
5.2 i	Glycolysis	Glycolysis, ATP and the link reaction	Covered
5.3 i	Link reaction and Krebs cycle	Glycolysis, ATP and the link reaction, The Krebs cycle and oxidative phosphorylation	Covered
5.3 ii	Link reaction and Krebs cycle	Glycolysis, ATP and the link reaction, The Krebs cycle and oxidative phosphorylation	Covered
5.4 i	Oxidative phosphorylation	The Krebs cycle and oxidative phosphorylation, Eukaryotic cell structure and organelles	Covered
5.4 ii	Oxidative phosphorylation	The Krebs cycle and oxidative phosphorylation	Covered
5.4 iii	Oxidative phosphorylation	The Krebs cycle and oxidative phosphorylation	Covered
5.4 iv	Oxidative phosphorylation	The Krebs cycle and oxidative phosphorylation	Covered
5.4 v	Oxidative phosphorylation	The Krebs cycle and oxidative phosphorylation, Eukaryotic cell structure and organelles	Covered
5.5 i	Anaerobic respiration	Anaerobic respiration and the respiratory quotient	Covered
5.5 ii	Anaerobic respiration	Anaerobic respiration and the respiratory quotient	Covered
5.5 iii	Anaerobic respiration	Anaerobic respiration and the respiratory quotient	Covered
5.5 iv	Anaerobic respiration	Anaerobic respiration and the respiratory quotient, Measuring respiration and photosynthesis rates	Covered
5.6 i	Photosynthetic pigments	Chloroplast structure and the light-dependent reactions, Measuring respiration and photosynthesis rates	Covered
5.6 ii	Photosynthetic pigments	Chloroplast structure and the light-dependent reactions, Chromatography and the separation of pigments	Covered
5.7 i	Photosynthesis	Chloroplast structure and the light-dependent reactions, Eukaryotic cell structure and organelles	Covered
5.7 ii	Photosynthesis	Chloroplast structure and the light-dependent reactions	Covered
5.7 iii	Photosynthesis	Chloroplast structure and the light-dependent reactions	Covered
5.7 iv	Photosynthesis	The Calvin cycle	Covered
5.7 v	Photosynthesis	The Calvin cycle	Covered
5.7 vi	Photosynthesis	The Calvin cycle	Covered
5.7 vii	Photosynthesis	The Calvin cycle	Covered
5.7 viii	Photosynthesis	Limiting factors and primary productivity	Covered

6 Microbiology and Pathogens

Ref	Specification heading	Taught in	Coverage
6.1 i	Microbial techniques	Industrial biotechnology and fermentation, Aseptic technique and the effect of antimicrobials	Covered
6.1 ii	Microbial techniques	Industrial biotechnology and fermentation, Aseptic technique and the effect of antimicrobials	Covered
6.1 iii	Microbial techniques	Industrial biotechnology and fermentation, Aseptic technique and the effect of antimicrobials	Covered except: Selective media are not taught in the microbiological sense. Broth culture is covered in detail as the stirred-tank fermenter, and agar plates are covered by the practical capability, which pours, spreads, seals and incubates them; so two of the board's three media are served. A medium formulated so that only some organisms will grow on it appears once in this library, in the hybridoma section of the antibodies lesson, where it selects fused cells from unfused ones. That is a different use of the same words and it teaches nothing about isolating a bacterium from a mixture, which is what core practical 13 needs and what this statement is about.
6.1 iv	Microbial techniques		Nothing here teaches this: None of the four ways of measuring the growth of a bacterial culture is taught. Total and viable cell counts, dilution plating with the colony count it yields, dry mass, and optical methods reading turbidity are all absent, and so is the distinction between counting the cells that are there and counting the cells that are alive. The growth curve those measurements produce is taught in two different lessons; how anybody obtained the numbers on its axis is not. Nothing was written because the mapped boards examine the curve and not the counting.
6.1 v	Microbial techniques	Populations and their limits, Industrial biotechnology and fermentation, Aseptic technique and the effect of antimicrobials	Covered except: The exponential growth rate constant is not calculated anywhere. All four phases are taught with the reason for each: lag while the population is small and the enzymes for a new substrate are made, log while nothing limits growth, stationary when deaths balance divisions, and the death phase that belongs to a closed culture rather than to the wild. Doubling arithmetic of the N = N0 x 2 to the power n kind is worked, and mean generation time is in the practical capability. The constant this statement names, taken from the logarithms of two population sizes and the time between them, is never set up or used.
6.2 i	Bacteria as pathogens	Pathogens and non-specific defences	Covered
6.2 ii	Bacteria as pathogens	Pathogens and non-specific defences	Covered except: Exotoxins and endotoxins are not distinguished, and neither Staphylococcus nor Salmonella is named. One of the board's three cases is served exactly as it asks: invasion of host tissue by Mycobacterium tuberculosis, with the granulomas and the point that much of the lung damage is the host's own inflammatory response. Toxins in general are taught well, and cholera toxin's mechanism is followed through cyclic AMP to a chloride channel to water potential. What is missing is the classification: a secreted protein against a component of the cell wall released when the bacterium dies, and the two genera the board attaches to them.
6.3 i	Action of antibiotics	Prokaryotic cells and viruses, Evidence for evolution, resistance and genetic drift, Aseptic technique and the effect of antimicrobials	Covered except: Bactericidal and bacteriostatic are not named or distinguished, and tetracycline is not mentioned. Penicillin is taught in full and correctly, blocking the cross-linking of murein so that a growing cell builds a wall it cannot hold together and bursts, which is a bactericidal mechanism described without the word; and ribosome-binding antibiotics that block translation at the 70S ribosome are taught too, which is where tetracycline would sit. Capability P09 goes as far as warning that a clear zone on a plate cannot say whether the organisms were killed or merely stopped, which is precisely this distinction, unnamed. Two terms and one named example are the gap.
6.4 i	Antibiotic resistance	Evidence for evolution, resistance and genetic drift, Prokaryotic cells and viruses	Covered
6.4 ii	Antibiotic resistance	Evidence for evolution, resistance and genetic drift, Infectious disease: transmission and control	Covered
6.5 i	Other pathogenic agents	Pathogens and non-specific defences, Infectious disease: transmission and control	Covered except: The stem rust fungus is absent. Transmission, mode of infection and pathogenic effect are all taught for two of the board's three organisms: influenza as a single-stranded RNA virus spread on droplets and replicating in airway epithelium, and Plasmodium as a protoctist carried by the female Anopheles mosquito and lysing red cells in synchrony. Puccinia graminis on wheat is never mentioned, and the only crop fungus anywhere in the library is black sigatoka on bananas, named in one clause. A student would meet the board's cereal example for the first time in the examination.
6.6 i	Problems of controlling endemic diseases	Infectious disease: transmission and control	Covered except: Two of the four things this statement asks for are missing. The social and economic implications of malaria control are taught properly: bed nets and the night-time bite they block, draining standing water to break the vector's life cycle, and the general rule that a control programme standing on one of the three axes falls over. The ethical implications are not argued anywhere, and nothing in the library describes how the scientific community validates a control method, which is the same institutional gap 3.1 vi and 10.4 iv record.
6.7 i	Response to infection	Pathogens and non-specific defences, The specific immune response	Covered
6.7 ii	Response to infection	The specific immune response	Covered except: Cytokines are never named. Every other item on the board's list is taught in the right order and with the right mechanism: a phagocyte presenting antigen on its own membrane, the T-helper cell with the complementary receptor selected and undergoing clonal expansion, the B cell binding antigen with its surface antibody and presenting it in turn, clonal selection at both cells, plasma cells and the antibody they secrete. What the activated T-helper cell releases in order to stimulate the B cell is described only as stimulation, so the class of signalling molecule the board names is absent.
6.7 iii	Response to infection	The specific immune response	Covered except: Cytokines again. Antigen-presenting cells are taught, and so are T-killer cells in unusual detail: binding an infected cell displaying viral antigen, releasing perforin to make pores, delivering granzymes through them and setting off apoptosis so the cell dies before the virus finishes replicating. The T-helper cell's role is stated with the right verb, activating a T-killer cell rather than becoming one, which is the error the lesson is written against; but the molecules it activates with are not named.
6.7 iv	Response to infection	The specific immune response	Covered
6.7 v	Response to infection	Antibodies, vaccination and the four kinds of immunity	Covered
6.7 vi	Response to infection	Antibodies, vaccination and the four kinds of immunity	Covered
6.7 vii	Response to infection	Antibodies, vaccination and the four kinds of immunity	Covered

7 Modern Genetics

Ref	Specification heading	Taught in	Coverage
7.1 i	Using gene sequencing	The genetic code and transcription, Genome analysis, genetic screening and gene therapy	Covered
7.1 ii	Using gene sequencing	Recombinant DNA technology, Genome analysis, genetic screening and gene therapy	Covered
7.2 i	Factors affecting gene expression	Control of gene expression	Covered
7.2 ii	Factors affecting gene expression	Control of gene expression	Covered
7.2 iii	Factors affecting gene expression	The genetic code and transcription, Control of gene expression	Covered
7.2 iv	Factors affecting gene expression	Control of gene expression	Covered
7.2 v	Factors affecting gene expression	Control of gene expression, Stem cells and cell potency	Covered
7.3 i	Stem cells	Stem cells and cell potency, Cell specialisation and biological organisation	Covered
7.3 ii	Stem cells	Stem cells and cell potency, Mutation, gene expression and cancer	Covered
7.3 iii	Stem cells	Stem cells and cell potency, Control of gene expression, Gametes, fertilisation and early development	Covered
7.3 iv	Stem cells	Stem cells and cell potency, Control of gene expression	Covered except: The genes are not named. Reprogramming is taught properly: a differentiated fibroblast is given four genes coding for transcription factors, those factors switch the cell's own silent genes back on, and the result is pluripotent, patient-specific and made without an embryo, with the caveats that the efficiency is low and that early viral delivery raised the risk of tumours. This statement asks for the artificial introduction of named genes, and Oct4, Sox2, Klf4 and c-Myc are never listed.
7.3 v	Stem cells	Stem cells and cell potency	Covered
7.4 i	Gene technology	Recombinant DNA technology	Covered
7.4 ii	Gene technology	Recombinant DNA technology, Genome analysis, genetic screening and gene therapy	Covered except: The gene gun is absent. Two of the routes the board wants are taught in full: plasmid vectors with transformation by ice-cold calcium chloride and heat shock or by electroporation, with the low efficiency stated honestly, and viral vectors in the gene therapy lesson, stripped of the genes that let them cause disease, with liposomes alongside them. Nothing describes firing DNA-coated particles into plant tissue, which is the method that matters for the crop plants 7.4 v and vi go on to argue about.
7.4 iii	Gene technology	Recombinant DNA technology	Covered
7.4 iv	Gene technology		Nothing here teaches this: Knockout mice are not taught. The question they answer is asked in this library and answered another way: siRNA is named as the standard laboratory method for finding out what a gene does by silencing it and seeing what stops working, and reprogrammed patient cells are taught as disease models. Disabling a gene in a whole animal, and the model organism that results, are never described, and no lesson uses the word knockout.
7.4 v	Gene technology	Recombinant DNA technology	Covered except: The soya bean is taught for a different modification. Herbicide-resistant soybean is one of three named GM organisms worked through in full, with the bacterial enzyme that glyphosate cannot inhibit, the cheaper weed control and reduced ploughing that follow, and the glyphosate-resistant weeds that followed those. What the board asks for is the other soya modification, altering the balance of fatty acids so that soya products do not oxidise, which improves the product rather than the farming, and that is absent.
7.4 vi	Gene technology	Recombinant DNA technology, Pharming, recombinant medicines and synthetic biology	Covered

8 Origins of Genetic Variation

Ref	Specification heading	Taught in	Coverage
8.1 i	Origins of genetic variation	Natural selection: variation, selection and allele frequency, Meiosis and the sources of genetic variation	Covered
8.1 ii	Origins of genetic variation	Meiosis and the sources of genetic variation, Natural selection: variation, selection and allele frequency	Covered
8.2 i	Transfer of genetic information	Monohybrid inheritance and genetic diagrams	Covered
8.2 ii	Transfer of genetic information	Monohybrid inheritance and genetic diagrams, Dihybrid inheritance, linkage, epistasis and the chi-squared test	Covered except: Pedigree diagrams are not taught as diagrams. Constructing a genetic cross is taught line by line in the order the marks are given, parental phenotypes, parental genotypes, gametes circled, offspring and ratio, with Punnett squares and test crosses, so the first half of the statement is fully served. Pedigree reasoning appears in prose, an affected son inherited the allele from his mother and a father gives his X to every daughter, and one worked question deduces parental genotypes from offspring counts; but the chart itself is never drawn or read, so the square and circle convention, the numbered generations, and the method of working an unknown genotype out of a family tree are all absent.
8.2 iii	Transfer of genetic information	Dihybrid inheritance, linkage, epistasis and the chi-squared test	Covered
8.2 iv	Transfer of genetic information	Dihybrid inheritance, linkage, epistasis and the chi-squared test, Meiosis and the sources of genetic variation	Concept covered; the board's example is not: The Drosophila cross the board names: black against grey body and long against vestigial wing.
8.2 v	Transfer of genetic information	Monohybrid inheritance and genetic diagrams	Covered
8.2 vi	Transfer of genetic information	Dihybrid inheritance, linkage, epistasis and the chi-squared test, Choosing, carrying out and concluding a statistical test	Covered
8.3 i	Gene pools	Natural selection: variation, selection and allele frequency, Speciation and reproductive isolation	Covered
8.3 ii	Gene pools	Evidence for evolution, resistance and genetic drift	Covered
8.3 iii	Gene pools	Evidence for evolution, resistance and genetic drift, Measuring biodiversity	Covered
8.3 iv	Gene pools	Population genetics and Hardy-Weinberg equilibrium	Covered

9 Control Systems

Ref	Specification heading	Taught in	Coverage
9.1 i	Homeostasis	Hormonal communication and negative feedback	Covered
9.1 ii	Homeostasis	Hormonal communication and negative feedback, Factors affecting enzyme rate: temperature, pH and concentration, Osmoregulation and kidney function, Thermoregulation in endotherms and ectotherms	Covered
9.1 iii	Homeostasis	Hormonal communication and negative feedback	Covered
9.2 i	Chemical control in mammals	Hormonal communication and negative feedback	Covered
9.2 ii	Chemical control in mammals	Hormonal communication and negative feedback, Control of gene expression	Covered
9.3 i	Chemical control in plants	Plant responses: tropisms, auxins and the classic experiments	Covered
9.3 ii	Chemical control in plants	Plant responses: tropisms, auxins and the classic experiments	Covered
9.3 iii	Chemical control in plants	Plant responses: tropisms, auxins and the classic experiments	Covered
9.3 iv	Chemical control in plants		Nothing here teaches this: Phytochrome is not taught, and the word does not appear anywhere in this library. Neither the control of flowering by day length nor photomorphogenesis appears either. Auxins, gibberellins, abscisic acid, ethene and cytokinins are all covered with mechanisms and commercial uses, and gibberellin's control of the amylase gene in the aleurone layer is worked as a gene-expression example, so this is a gap in one pigment and the two responses it governs rather than in plant chemical control generally. Nothing was written because none of the three boards mapped before today names phytochrome.
9.4 i	Structure and function of the mammalian nervous system	Organisation of the nervous system	Covered
9.4 ii	Structure and function of the mammalian nervous system		Nothing here teaches this: The structure of the spinal cord is not taught. It is named as half of the central nervous system and as the route a reflex takes without going up to the brain, and the reflex arc through it is drawn neurone by neurone with the sensory cell body placed in a ganglion just outside it. None of the structure this statement asks for is present: no grey matter and white matter, no central canal, no dorsal and ventral roots, and no account of why the cell bodies sit where they do. Nothing was written because the mapped boards examine the reflex pathway rather than the anatomy of the cord it runs through.
9.4 iii	Structure and function of the mammalian nervous system	Organisation of the nervous system	Covered
9.4 iv	Structure and function of the mammalian nervous system	Organisation of the nervous system	Covered
9.4 v	Structure and function of the mammalian nervous system	Organisation of the nervous system	Covered
9.5 i	Nervous transmission	The action potential and its propagation	Covered
9.5 ii	Nervous transmission	The action potential and its propagation	Covered
9.5 iii	Nervous transmission	The action potential and its propagation	Covered
9.5 iv	Nervous transmission	The synapse: transmission, and why it runs one way, Organisation of the nervous system, The heart and cardiac cycle	Covered
9.5 v	Nervous transmission	The synapse: transmission, and why it runs one way	Covered
9.6 i	Effects of drugs on the nervous system	The synapse: transmission, and why it runs one way, The action potential and its propagation	Covered except: Two of the board's three named substances are missing. Nicotine is taught exactly as the board wants it, binding acetylcholine receptors and activating them so the postsynaptic neurone depolarises as though acetylcholine had bound. Cobra venom is not named, though curare is taught as the receptor blocker that binds without activating, which is the same mechanism under another name, so a student meets the effect but not the example. Lidocaine is not named at all; voltage-gated sodium channels are taught in full in the action-potential lesson, so what is missing there is a drug that blocks them and the local anaesthesia that follows, not the channel.
9.7 i	Detection of light by mammals	Receptors: transduction and the reflex arc	Covered except: The retina is taught as two receptor types rather than as a structure. Rods and cones are covered thoroughly, their pigments, the light each needs, their numbers, their distribution across the peripheral retina and the fovea, and the bipolar neurones they connect to, with convergence explaining sensitivity and acuity. What a labelled diagram of the retina would also need is absent: the layered arrangement of the three cell types, the ganglion cells whose axons form the optic nerve, and the blind spot where that nerve leaves the eye.
9.7 ii	Detection of light by mammals	Receptors: transduction and the reflex arc	Covered
9.7 iii	Detection of light by mammals	Receptors: transduction and the reflex arc	Covered
9.8 i	Control of heart rate in mammals	The heart and cardiac cycle, Organisation of the nervous system	Covered
9.8 ii	Control of heart rate in mammals	Hormonal communication and negative feedback, The heart and cardiac cycle	Covered
9.9 i	Osmoregulation and temperature regulation	Osmoregulation and kidney function	Covered
9.9 ii	Osmoregulation and temperature regulation	The liver: detoxification, deamination and the making of urea, Osmoregulation and kidney function	Covered
9.9 iii	Osmoregulation and temperature regulation	Osmoregulation and kidney function	Covered
9.9 iv	Osmoregulation and temperature regulation	Osmoregulation and kidney function, Hormonal communication and negative feedback	Covered
9.9 v	Osmoregulation and temperature regulation	Osmoregulation and kidney function, Lipids: triglycerides, phospholipids and ester bonds	Covered
9.9 vi	Osmoregulation and temperature regulation	Thermoregulation in endotherms and ectotherms	Covered
9.9 vii	Osmoregulation and temperature regulation	Thermoregulation in endotherms and ectotherms	Covered

10 Ecosystems

Ref	Specification heading	Taught in	Coverage
10.1 i	The nature of ecosystems	Populations and their limits	Covered
10.1 ii	The nature of ecosystems	Limiting factors and primary productivity, Populations and their limits	Covered
10.1 iii	The nature of ecosystems	Limiting factors and primary productivity	Covered except: Ecological pyramids are not taught, and the word does not appear in the library in this sense. The second half of the statement is fully served: biomass and energy transfer between trophic levels is taught with the percentage calculation, the four causes of loss, the reason transfer to a mammal or bird is lower than to an insect, dry mass measured to constant mass in an oven, and the energy in that mass found by calorimetry. Absent are pyramids of numbers, of biomass and of energy as three ways of drawing an ecosystem, and the advantage and disadvantage of each, which is the comparison this statement is built around.
10.1 iv	The nature of ecosystems	Measuring biodiversity, Succession and environmental change, Field sampling, distribution and behavioural response	Covered except: The ACFOR abundance scale is absent, and types of quadrat are not separated from one another. Most of what the statement asks for is taught well: quadrats placed at randomly generated coordinates with the reason, belt and line transects for a gradient with the warning that a transect where there is no gradient produces a tidy graph of nothing, percentage cover for plants that grow as a mat, frequency where presence is what is wanted, and counts of individuals for the diversity index that needs them. Mark, release and recapture is taught for mobile animals, and the invertebrate collecting kit is given item by item with the bias of each. What is missing is the frame, point and gridded quadrats as distinct tools, and the five-point subjective abundance scale the board names.
10.1 v	The nature of ecosystems	Measuring biodiversity, Succession and environmental change, Field sampling, distribution and behavioural response	Covered
10.1 vi	The nature of ecosystems	Choosing, carrying out and concluding a statistical test, Averages, spread and the null hypothesis, Field sampling, distribution and behavioural response	Covered
10.2 i	Energy transfer through ecosystems	Limiting factors and primary productivity	Covered
10.2 ii	Energy transfer through ecosystems	Limiting factors and primary productivity	Covered
10.2 iii	Energy transfer through ecosystems	Nutrient cycles: nitrogen, phosphorus and eutrophication	Covered
10.3 i	Changes in ecosystems	Succession and environmental change	Covered
10.3 ii	Changes in ecosystems	Populations and their limits, Succession and environmental change, Field sampling, distribution and behavioural response	Covered
10.4 i	Human effects on ecosystems	The carbon cycle and climate change, Managing ecosystems sustainably, Nutrient cycles: nitrogen, phosphorus and eutrophication	Covered
10.4 ii	Human effects on ecosystems	Conservation in situ and ex situ	Covered
10.4 iii	Human effects on ecosystems	Managing ecosystems sustainably, Conservation in situ and ex situ	Covered
10.4 iv	Human effects on ecosystems		Nothing here teaches this: This is 3.1 vi again in its climate-change form, and it fails for the same reason: journals, peer review and conferences are not taught anywhere in this library, so nothing explains how a claim about a changing climate is checked before it is believed. What is taught is the evidence and the reasoning over it: the measured rise in atmospheric carbon dioxide with its consequences for species distribution, and a whole section of the scientific-method unit on arguing a correlation up to a causal claim, with confounding variables and the criteria a causal argument has to meet. The institutions are the gap, not the argument, and one piece of writing would close both this row and 3.1 vi.

What each paper is, how long it runs and where Pearson Edexcel publishes it: 9BN0 past papers.

What each paper is, how long it runs and where Pearson Edexcel publishes it: 9BI0 past papers.

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