# Key stage 3: Science

A course roadmap (science). Language: en. By @si. Licence: CC BY-SA 4.0. 0 of 87 concepts ready. In the app: https://ai.page/roadmap/uk-nc-2013-key-stage-3-science

Part of: [National Curriculum in England](https://ai.page/roadmap/uk-nc-2013.md)

Goal: The national curriculum in England: Key stages 1 and 2 framework document, Key stage 3

## 1. Adaptation and inheritance

- [Evidence for Evolution](https://ai.page/c/evidence-for-evolution/index.md): Describe the main types of evidence for evolution: the fossil record (change over time), comparative anatomy (homologous structures), and the geographic distribution of related species
- [Chromosomes, Genes & DNA](https://ai.page/c/chromosomes-genes-and-dna/index.md): Describe the relationship between chromosomes, genes, and DNA in heredity, including the double helix structure of DNA and the historical roles of Watson, Crick, Franklin, and Wilkins
- [Variation in Species](https://ai.page/c/variation-in-species/index.md): Explain variation within and between species, distinguishing between continuous variation (e.g. height) and discontinuous variation (e.g. blood group), and between genetic and environmental causes
- [Genetic Mutation](https://ai.page/c/genetic-mutation/index.md): Explain genetic mutation as a random change in DNA sequence, describe causes of mutation (e.g. radiation, chemicals, copying errors), and explain that most mutations are neutral, some harmful, and a few beneficial
- [How Natural Selection Works](https://ai.page/c/how-natural-selection-works/index.md): Explain natural selection as the mechanism of evolution: heritable variation + competition for resources + differential survival and reproduction = change in allele frequency over generations
- [Extinction & Rapid Change](https://ai.page/c/extinction-and-rapid-change/index.md): Explain how environmental change can outpace a species' ability to adapt through natural selection, leading to extinction, using historical and contemporary examples
- [Biodiversity & Resilience](https://ai.page/c/biodiversity-and-resilience/index.md): Explain what biodiversity means, why high biodiversity makes ecosystems more resilient, and describe the ways human activity threatens biodiversity (habitat destruction, pollution, invasive species, climate change)
- [Predicting Inherited Traits](https://ai.page/c/predicting-inherited-traits/index.md): Explain how alleles are inherited in sexual reproduction and use Punnett squares to predict the probability of offspring inheriting a characteristic, including dominant and recessive alleles

## 2. Cells and organisation

- [Cells Under the Microscope](https://ai.page/c/cells-under-the-microscope/index.md): Understand that all living organisms are made of cells and use a light microscope to observe, interpret, and record cell structure
- [Using a Microscope](https://ai.page/c/using-a-microscope/index.md): Use a light microscope correctly to prepare, focus, and examine biological specimens, including making accurate labelled drawings at an appropriate magnification
- [Parts of Plant and Animal Cells](https://ai.page/c/parts-of-plant-and-animal-cells/index.md): Describe the functions of the main components of plant and animal cells: cell wall, cell membrane, cytoplasm, nucleus, vacuole, mitochondria, ribosomes, and chloroplasts
- [Plant Cells vs Animal Cells](https://ai.page/c/plant-cells-vs-animal-cells/index.md): Compare plant and animal cells, identifying shared features and structures unique to plant cells (cell wall, vacuole, chloroplasts)
- [Single-Celled Organisms](https://ai.page/c/single-celled-organisms/index.md): Explain how unicellular organisms such as bacteria and Amoeba carry out all the functions of life within a single cell
- [Cells to Organ Systems](https://ai.page/c/cells-to-organ-systems/index.md): Describe the hierarchical organisation of multicellular organisms: cells → tissues → organs → organ systems → organism

## 3. Ecosystem processes

- [Food Webs & Interdependence](https://ai.page/c/food-webs-and-interdependence/index.md): Construct and interpret food webs showing the interdependence of organisms in an ecosystem, explaining how a change in one population affects others
- [Energy Loss Between Levels](https://ai.page/c/energy-loss-between-levels/index.md): Explain how energy is transferred between trophic levels in a food chain, why energy is lost at each stage, and use pyramids of biomass/numbers to represent this
- [Pollination & Pollinator Decline](https://ai.page/c/pollination-and-pollinator-decline/index.md): Explain the importance of insect pollination for plant reproduction and human food security, and discuss the consequences of pollinator decline
- [Toxins Building Up in Food Chains](https://ai.page/c/toxins-building-up-in-food-chains/index.md): Explain how organisms affect and are affected by their environment, including the bioaccumulation of toxic materials (e.g. pesticides, heavy metals) through food chains
- [The Carbon Cycle](https://ai.page/c/the-carbon-cycle/index.md): Describe the carbon cycle, tracing carbon through photosynthesis, respiration, feeding, decomposition, and combustion, and explain the role of each process
- [The Water Cycle](https://ai.page/c/the-water-cycle/index.md): Describe the water cycle, tracing water through evaporation, condensation, precipitation, surface runoff, and transpiration in plants, explaining how the sun drives the cycle
- [Species Distribution & Change](https://ai.page/c/species-distribution-and-change/index.md): Explain how environmental change (climate change, habitat loss, pollution) affects the distribution of species, including range shifts, local extinction, and invasive species

## 4. Gas exchange systems

- [How Diffusion Works](https://ai.page/c/how-diffusion-works/index.md): Explain diffusion as the net movement of particles from a region of higher concentration to lower concentration, and describe its role in moving materials (oxygen, carbon dioxide, glucose) in and between cells
- [Gas Exchange & Breathing](https://ai.page/c/gas-exchange-and-breathing/index.md): Describe the structure of the human gas exchange system (trachea, bronchi, bronchioles, alveoli) and explain how the mechanism of breathing — using pressure changes from rib and diaphragm movement — moves air in and out of the lungs
- [Heart Structure & Double Circulation](https://ai.page/c/heart-structure-and-double-circulation/index.md): Describe the structure of the heart (four chambers, valves, coronary arteries) and explain how it pumps deoxygenated blood to the lungs and oxygenated blood to the body in a double circulatory system
- [Aerobic Respiration](https://ai.page/c/aerobic-respiration/index.md): Explain aerobic respiration as the process by which organisms release energy from glucose using oxygen, producing carbon dioxide and water; write and interpret the word equation: glucose + oxygen → carbon dioxide + water
- [Anaerobic Respiration](https://ai.page/c/anaerobic-respiration/index.md): Explain anaerobic respiration in animals as the incomplete breakdown of glucose to lactic acid when oxygen is in short supply, causing muscle fatigue; contrast this with aerobic respiration in terms of energy yield and products

## 5. Health

- [Body Temperature Regulation](https://ai.page/c/body-temperature-regulation/index.md): Explain how the human body detects and responds to environmental changes including temperature, including the role of the skin in temperature regulation (sweating, shivering, vasodilation, vasoconstriction)
- [Effects of Drugs & Alcohol](https://ai.page/c/effects-of-drugs-and-alcohol/index.md): Explain the effects of recreational drugs including alcohol, tobacco, and illegal substances on behaviour, health, and body systems, and distinguish between depressants, stimulants, and hallucinogens
- [Pathogens & the Immune System](https://ai.page/c/pathogens-and-the-immune-system/index.md): Explain how pathogens (bacteria, viruses, and fungi) cause disease and describe how the immune system responds, including the roles of white blood cells (phagocytosis, antibody production) and the concept of immunity

## 6. Nutrition and digestion

- [Nutrients in a Healthy Diet](https://ai.page/c/nutrients-in-a-healthy-diet/index.md): Identify the seven components of a healthy diet — carbohydrates, lipids, proteins, vitamins, minerals, dietary fibre, and water — and explain the role of each in the body
- [Calculating Dietary Energy](https://ai.page/c/calculating-dietary-energy/index.md): Calculate and evaluate energy intake and requirements in a healthy daily diet, interpreting food labels and nutritional data
- [Diet Imbalance & Deficiency](https://ai.page/c/diet-imbalance-and-deficiency/index.md): Explain the health consequences of an imbalanced diet including obesity (excess energy), starvation (severe energy deficit), and deficiency diseases (lack of specific nutrients, e.g. scurvy, rickets)
- [Digestion & Enzymes](https://ai.page/c/digestion-and-enzymes/index.md): Describe the organs of the human digestive system and how food is physically and chemically digested, including the role of enzymes as biological catalysts
- [Gut Bacteria & Digestion](https://ai.page/c/gut-bacteria-and-digestion/index.md): Explain the role of gut microbiome bacteria in digestion, including breaking down dietary fibre and contributing to a healthy gut environment
- [Photosynthesis](https://ai.page/c/photosynthesis/index.md): Explain photosynthesis as the process by which plants use light energy to convert carbon dioxide and water into glucose and oxygen, and describe how mineral nutrients are absorbed through roots

## 7. Reproduction

- [Human Reproduction](https://ai.page/c/human-reproduction/index.md): Describe the structure and function of the male and female human reproductive systems, and explain the processes of fertilisation, gestation, and birth including the role of the placenta
- [Plant Reproduction](https://ai.page/c/plant-reproduction/index.md): Describe the structure of a flower and explain the processes of wind and insect pollination, fertilisation, seed and fruit formation, and seed dispersal in plants

## 8. The skeletal and muscular systems

- [The Human Skeleton](https://ai.page/c/the-human-skeleton/index.md): Describe the structure and four main functions of the human skeleton: support, protection, movement, and production of blood cells in bone marrow
- [Joints, Tendons & Ligaments](https://ai.page/c/joints-tendons-and-ligaments/index.md): Explain biomechanics — the interaction between skeleton and muscles at joints, including the roles of tendons (attach muscle to bone) and ligaments (attach bone to bone)
- [Muscles Work in Pairs](https://ai.page/c/muscles-work-in-pairs/index.md): Explain that muscles work in antagonistic pairs — one contracts while the other relaxes — to produce movement, using the bicep and tricep as a key example

## 9. Atoms, elements and compounds

- [Atoms, Elements & Compounds](https://ai.page/c/atoms-elements-and-compounds/index.md): Explain the differences between atoms, elements, and compounds; describe the simple Bohr model of the atom (nucleus with protons and neutrons, electrons in shells); and write and interpret chemical symbols and simple formulae
- [Physical vs Chemical Changes](https://ai.page/c/physical-vs-chemical-changes/index.md): Distinguish between physical changes (reversible, no new substances formed) and chemical changes (new substances formed, often irreversible), using conservation of mass to understand both types
- [The Periodic Table](https://ai.page/c/the-periodic-table/index.md): Describe the organisation of the periodic table into periods and groups, explain the contribution of Mendeleev, and use the table to identify metals, non-metals, and predict patterns in reactivity
- [Metals vs Non-Metals](https://ai.page/c/metals-vs-non-metals/index.md): Compare the physical and chemical properties of metals and non-metals, explaining metallic properties (malleability, lustre, conductivity) and how position in the periodic table predicts reactivity

## 10. Chemical reactions

- [Types of Chemical Reaction](https://ai.page/c/types-of-chemical-reaction/index.md): Identify and describe four types of chemical reaction: combustion (burning in oxygen), oxidation (gain of oxygen), thermal decomposition (breaking down by heat), and displacement (more reactive metal replaces less reactive one)
- [Acids, Alkalis & pH](https://ai.page/c/acids-alkalis-and-ph/index.md): Define acids and alkalis in terms of hydrogen ion concentration, describe the pH scale (0–14), and explain how indicators are used to identify and measure acidity or alkalinity
- [Acid Reactions & Salts](https://ai.page/c/acid-reactions-and-salts/index.md): Describe and write word equations for the reactions of acids with metals, alkalis (neutralisation), and metal oxides/hydroxides, identifying the salt produced in each case
- [Ceramics, Polymers & Composites](https://ai.page/c/ceramics-polymers-and-composites/index.md): Describe the properties and uses of ceramics (hard, brittle, heat-resistant), polymers (flexible, lightweight, variable), and composites (combine properties of constituent materials), giving real-world examples of each

## 11. Earth and atmosphere

- [Earth's Atmosphere & CO2](https://ai.page/c/earth-s-atmosphere-and-co2/index.md): Describe the composition of Earth's atmosphere (mainly nitrogen and oxygen, with small amounts of CO₂ and other gases), explain how human activity increases CO₂, and describe the impact on global climate
- [The Rock Cycle](https://ai.page/c/the-rock-cycle/index.md): Explain the rock cycle: how igneous rocks form from magma, sedimentary rocks from compressed sediment, and metamorphic rocks from heat and pressure, and how all rock types can transform into one another over geological time
- [Finite Resources & Recycling](https://ai.page/c/finite-resources-and-recycling/index.md): Explain that many raw materials (metals, fossil fuels, minerals) are finite resources, describe the environmental costs of extraction, and evaluate the benefits of recycling and the circular economy

## 12. Energetics

- [Reactions That Release or Absorb Heat](https://ai.page/c/reactions-that-release-or-absorb-heat/index.md): Distinguish between exothermic reactions (release energy, temperature rises) and endothermic reactions (absorb energy, temperature falls), with everyday and industrial examples

## 13. Materials

- [The Reactivity Series](https://ai.page/c/the-reactivity-series/index.md): Order common metals in the reactivity series and explain how a more reactive metal displaces a less reactive one; describe how carbon is used to extract metals from their oxides in industry

## 14. Pure and impure substances

- [Pure Substances & Mixtures](https://ai.page/c/pure-substances-and-mixtures/index.md): Distinguish between pure substances and mixtures, identify formulations as useful mixtures with precise compositions, and use melting and boiling points to test for purity
- [Separating Mixtures](https://ai.page/c/separating-mixtures-science/index.md): Select and carry out appropriate separation techniques for different types of mixtures: filtration (insoluble solids), distillation (liquids by boiling point), crystallisation (dissolved solids), and chromatography (coloured substances)

## 15. The particulate nature of matter

- [The Particle Model](https://ai.page/c/the-particle-model/index.md): Use the particle model to explain the properties of solids, liquids, and gases — including differences in arrangement, movement, and spacing — and apply the model to explain density, compressibility, and the anomalous expansion of water
- [How Materials Change State](https://ai.page/c/how-materials-change-state/index.md): Explain melting, freezing, boiling, condensing, and sublimation using the particle model, interpreting heating and cooling curves to identify melting and boiling points

## 16. Energy

- [Energy stores and transfers](https://ai.page/c/energy-stores-and-transfers/index.md): Identify the main energy stores (kinetic, gravitational potential, elastic potential, thermal, chemical, nuclear, electromagnetic) and the pathways by which energy is transferred between stores (mechanically, electrically, by heating, by radiation)
- [Renewable vs non-renewable energy](https://ai.page/c/renewable-vs-non-renewable-energy/index.md): Distinguish between renewable energy resources (solar, wind, hydroelectric, tidal, geothermal, biomass) and non-renewable resources (coal, oil, gas, nuclear), comparing their advantages, disadvantages, and environmental impacts
- [Energy can't be created or destroyed](https://ai.page/c/energy-can-t-be-created-or-destroyed/index.md): Explain the principle of conservation of energy (energy cannot be created or destroyed, only transferred between stores), and describe how energy is dissipated as thermal energy to the surroundings in all real processes
- [Efficiency, Sankey diagrams, and work done](https://ai.page/c/efficiency-sankey-diagrams-and-work-done/index.md): Calculate energy efficiency as the ratio of useful output energy to total input energy, construct and interpret Sankey diagrams, and calculate work done using work = force × distance
- [Power: watts and energy per second](https://ai.page/c/power-watts-and-energy-per-second/index.md): Define power as the rate of energy transfer (power = energy ÷ time, measured in watts), and compare energy transfer rates in different everyday contexts
- [Conduction, convection, and radiation](https://ai.page/c/conduction-convection-and-radiation/index.md): Describe and compare the three mechanisms of heat transfer — conduction (particle vibration through solids), convection (fluid movement in liquids/gases), and radiation (infrared waves) — and explain that the rate of transfer depends on temperature difference
- [Heating experiments and Q = mcΔT](https://ai.page/c/heating-experiments-and-q-mc-t/index.md): Plan and carry out experiments to measure energy transferred during heating, including using the equation Q = mcΔT, recording temperature changes over time, and evaluating sources of error

## 17. Motion and forces

- [Speed & Distance-Time Graphs](https://ai.page/c/speed-and-distance-time-graphs/index.md): Calculate average speed using the equation speed = distance ÷ time, represent journeys on distance-time graphs, and interpret gradient as speed and flat sections as stationary periods
- [Mass vs Weight](https://ai.page/c/mass-vs-weight/index.md): Distinguish between mass (amount of matter, measured in kg) and weight (gravitational force, measured in N), use the equation weight = mass × gravitational field strength, and explain why g differs on other planets and stars
- [Relative Motion](https://ai.page/c/relative-motion/index.md): Explain relative motion — how the apparent speed and direction of an object depends on the observer's own motion — using everyday examples such as trains and cars passing
- [Resultant Forces](https://ai.page/c/resultant-forces/index.md): Describe forces as vector quantities with both magnitude and direction, distinguish between balanced forces (zero resultant, no change in motion) and unbalanced forces (non-zero resultant, causes acceleration or deceleration)
- [Deformation & Fluid Pressure](https://ai.page/c/deformation-and-fluid-pressure/index.md): Explain forces associated with deforming objects (elastic and inelastic deformation), thermal expansion and contraction of materials, and how fluid pressure acts in all directions and increases with depth
- [Moments, Pressure & Hooke's Law](https://ai.page/c/moments-pressure-and-hooke-s-law/index.md): Calculate the turning effect (moment = force × perpendicular distance), explain how pressure is transmitted equally in liquids (Pascal's principle) and the concept of atmospheric pressure, and describe Hooke's Law (extension ∝ force up to the elastic limit)
- [Newton's First & Second Laws](https://ai.page/c/newton-s-first-and-second-laws/index.md): State and apply Newton's First Law (an object stays at rest or constant velocity unless acted on by a resultant force) and Second Law (force = mass × acceleration), including the relationship between mass, force, and acceleration
- [Newton's Third Law](https://ai.page/c/newton-s-third-law/index.md): State and apply Newton's Third Law: every force has an equal and opposite reaction force acting on a different object, distinguishing action-reaction pairs from balanced forces
- [Magnetic Fields](https://ai.page/c/magnetic-fields/index.md): Describe magnetic poles (north and south), explain attraction and repulsion between poles, describe magnetic field lines plotted using a compass, and explain the Earth's magnetic field and its practical uses
- [Investigating Forces](https://ai.page/c/investigating-forces/index.md): Plan and carry out investigations into forces, including measuring force with a newton meter, investigating Hooke's Law, and collecting and interpreting motion data to test Newton's laws

## 18. Space physics

- [The solar system (age 11+)](https://ai.page/c/the-solar-system-age-11/index.md): Describe the detailed structure of the solar system, including moons, asteroids, and comets, compare orbital periods and distances of the planets, and distinguish between planets, dwarf planets, and other bodies
- [Why We Have Seasons](https://ai.page/c/why-we-have-seasons/index.md): Explain that the seasons are caused by the tilt of Earth's axis during its orbit around the Sun, distinguishing this from the common misconception that seasons are caused by changing distance from the Sun
- [Phases of the Moon](https://ai.page/c/phases-of-the-moon/index.md): Explain the phases of the Moon as the changing angle of sunlight on the lunar surface as seen from Earth, and describe how solar and lunar eclipses occur
- [Universal Gravitation](https://ai.page/c/universal-gravitation/index.md): Describe gravity as a universal attractive force between all masses, explain that orbital motion arises because gravity provides the centripetal force keeping objects in orbit, and compare gravitational field strengths on different planets
- [Galaxies and the universe](https://ai.page/c/galaxies-and-the-universe/index.md): Describe the scale of the universe, including the structure of galaxies, the position of the Sun in the Milky Way, and the use of light years as a unit of distance, and appreciate why space exploration requires enormous timescales
- [Life Cycle of a Star](https://ai.page/c/life-cycle-of-a-star/index.md): Describe the life cycle of a star from nebula through main sequence to its end state (white dwarf, neutron star, or black hole depending on mass), and relate the life cycle to the origin of elements heavier than hydrogen

## 19. Waves

- [Reflection & Refraction](https://ai.page/c/reflection-and-refraction/index.md): State the law of reflection (angle of incidence = angle of reflection) and explain refraction as the change in speed and direction when light crosses a boundary between two media; apply ray diagrams for plane mirrors and refracting surfaces
- [Wave Properties & Types](https://ai.page/c/wave-properties-and-types/index.md): Describe waves in terms of amplitude, wavelength, frequency, and wave speed; distinguish transverse waves (oscillation perpendicular to direction of travel) from longitudinal waves (oscillation parallel); and use the wave equation v = fλ
- [The Electromagnetic Spectrum](https://ai.page/c/the-electromagnetic-spectrum/index.md): Describe the full electromagnetic spectrum from radio waves to gamma rays, in order of increasing frequency and energy; explain that all EM waves travel at the same speed in a vacuum; and describe the uses and hazards of different regions
- [How Sound Waves Travel](https://ai.page/c/how-sound-waves-travel/index.md): Explain that sound is produced by vibrating objects and travels as a longitudinal pressure wave through solids, liquids, and gases; describe reflection of sound (echoes) and absorption; explain why sound cannot travel through a vacuum
- [Ray Diagrams & Images](https://ai.page/c/ray-diagrams-and-images/index.md): Construct ray diagrams to show the formation of images by plane mirrors and converging lenses, identifying whether images are real or virtual, magnified or diminished, upright or inverted
- [Waves & Different Materials](https://ai.page/c/waves-and-different-materials/index.md): Explain how waves can be absorbed, transmitted, or reflected by different materials, and apply these interactions to explain colour perception, sight, communication technologies, and the effects of different surfaces on wave behaviour
- [White Light & Colour](https://ai.page/c/white-light-and-colour/index.md): Explain that white light is a mixture of all visible colours (ROYGBIV), describe dispersion through a prism, explain why objects appear coloured (selective reflection and absorption of wavelengths), and describe colour mixing with filters

## Health: 0 of 100

Of its 87 own concepts: 0 have an explanation, 0 have practice, 0 have a measurement question, 0 have a checked version.

Findings (each is a task for anyone's AI):

- Evidence for Evolution has no explanation yet
- Chromosomes, Genes & DNA comes before Cells Under the Microscope, which it needs
- Chromosomes, Genes & DNA has no explanation yet
- Variation in Species has no explanation yet
- Genetic Mutation has no explanation yet
- How Natural Selection Works has no explanation yet
- Extinction & Rapid Change has no explanation yet
- Biodiversity & Resilience comes before Food Webs & Interdependence, which it needs
- Biodiversity & Resilience has no explanation yet
- Predicting Inherited Traits has no explanation yet
- Cells Under the Microscope has no explanation yet
- Using a Microscope has no explanation yet
- Parts of Plant and Animal Cells has no explanation yet
- Plant Cells vs Animal Cells has no explanation yet
- Single-Celled Organisms has no explanation yet
- Cells to Organ Systems has no explanation yet
- Food Webs & Interdependence has no explanation yet
- Energy Loss Between Levels has no explanation yet
- Pollination & Pollinator Decline has no explanation yet
- Toxins Building Up in Food Chains has no explanation yet
- The Carbon Cycle comes before Aerobic Respiration, which it needs
- The Carbon Cycle comes before Photosynthesis, which it needs
- The Carbon Cycle has no explanation yet
- The Water Cycle has no explanation yet
- Species Distribution & Change has no explanation yet
- How Diffusion Works has no explanation yet
- Gas Exchange & Breathing has no explanation yet
- Heart Structure & Double Circulation has no explanation yet
- Aerobic Respiration has no explanation yet
- Anaerobic Respiration has no explanation yet
- Body Temperature Regulation has no explanation yet
- Effects of Drugs & Alcohol has no explanation yet
- Pathogens & the Immune System has no explanation yet
- Nutrients in a Healthy Diet has no explanation yet
- Calculating Dietary Energy has no explanation yet
- Diet Imbalance & Deficiency has no explanation yet
- Digestion & Enzymes has no explanation yet
- Gut Bacteria & Digestion has no explanation yet
- Photosynthesis has no explanation yet
- Human Reproduction has no explanation yet
- Plant Reproduction has no explanation yet
- The Human Skeleton has no explanation yet
- Joints, Tendons & Ligaments has no explanation yet
- Muscles Work in Pairs has no explanation yet
- Atoms, Elements & Compounds comes before The Particle Model, which it needs
- Atoms, Elements & Compounds has no explanation yet
- Physical vs Chemical Changes has no explanation yet
- The Periodic Table has no explanation yet
- Metals vs Non-Metals has no explanation yet
- Types of Chemical Reaction has no explanation yet

Credit: The structure of The national curriculum in England: Key stages 1 and 2 framework document; concepts from the Marble Skill Taxonomy (v1), © Generative Spark, Inc. (withmarble.com), text CC BY-SA 4.0, database ODbL 1.0: https://github.com/withmarbleapp/os-taxonomy, mapped to its standards by Marble.