Explore
GCSEOCR
Combined Science
Start learning
Browse allCurriculum Modules
Cells as the basic unit of lifePlant cells vs animal cells: key similarities and differencesProkaryotic cells vs eukaryotic cellsCell organelles and their functionsUsing a light microscope safely and correctlyPreparing slides and using stains to improve contrastCalculating magnification and image sizeComparing light and electron micrographs (what each can show)The role of DNA in cells (genetic material as a code)Proteins as biological molecules with specific functionsEnzymes as biological catalystsLock-and-key model and enzyme specificityFactors affecting enzyme activity: temperature, pH, substrate concentration
What respiration is and why cells need itAerobic respiration: word equation and key ideasAnaerobic respiration in musclesAnaerobic respiration in microorganisms (fermentation basics)Comparing aerobic vs anaerobic respiration (energy release)Respiration as an enzyme-controlled processUsing respiration ideas to explain exercise and recoveryInterpreting simple data about respiration rate
Photosynthesis as a chemical reaction in plantsThe word equation and what it meansChloroplasts and chlorophyll: where photosynthesis happensHow light intensity affects photosynthesisHow carbon dioxide concentration affects photosynthesisHow temperature affects photosynthesisLimiting factors and predicting the rate-limiting factorUsing glucose made in photosynthesis (storage and transport)Linking photosynthesis and respiration in ecosystems
Diffusion: what it is and what affects the rateOsmosis: movement of water and partially permeable membranesActive transport: moving substances against a concentration gradientComparing diffusion, osmosis and active transportFrom cells to tissues to organs to organ systemsMitosis as cell division for growth and repairStem cells: what they are and why they matterExchange surfaces: what makes them efficientPlant transport tissues: xylem and phloem (what they carry)Transpiration basics and why plants lose water
Surface area to volume ratio and why it mattersDiffusion distance and exchange efficiencyWhy multicellular organisms need transport systemsThe human circulatory system: overview and purposeDouble circulatory system in mammalsThe heart: chambers, valves and blood vesselsArteries, veins and capillaries: structure and functionBlood components: plasma, red cells, white cells and plateletsGas exchange in the lungs: structure and function of alveoliInterpreting circulatory/gas exchange data in exam-style questions
The nervous system: CNS, sensory receptors and effectorsStimulus–response pathways and survival valueReflex actions and reflex arcsSynapses (simple model) and neurotransmittersThe endocrine system and hormone signallingComparing nervous vs hormonal controlHomeostasis: maintaining stable internal conditionsThermoregulation: sweating, shivering and blood flow changesBlood glucose control: insulin and glucagonDiabetes (type 1 and type 2 at GCSE level)Kidneys and osmoregulation (water balance)Negative feedback as a control mechanism
What an ecosystem is (biotic and abiotic factors)Levels of organisation: organism to community to ecosystemFood chains and trophic levelsFood webs and interdependenceCompetition and predator–prey relationshipsPyramids of number, biomass and energyDecomposers and nutrient recyclingThe carbon cycleThe water cycleBiodiversity: what it means and why it mattersHuman impacts on ecosystems (habitat loss, pollution)
DNA, genes and chromosomes: the big pictureGenetic terms: genotype, phenotype and allelesDominant and recessive inheritanceMonohybrid crosses using Punnett squaresInherited disorders (using clear examples)Sex determination (XX/XY) and inheritance patternsVariation: genetic vs environmentalMutation as a source of new variationNatural selection: how it works, step by stepEvolution and adaptation (linking to survival and reproduction)Selective breeding: process, benefits and drawbacksAntibiotic resistance as an example of evolution in action
Monitoring ecosystems and environmental changePollution and biodiversity: causes and consequencesFood security: why feeding humans is challengingIncreasing food production: farming methods and trade-offsFertilisers and eutrophication (cause → effect chains)Genetic modification in crops: potential benefits and concernsHealth and disease: what the terms meanCommunicable vs non-communicable diseasesPathogens (virus, bacteria, protist, fungi) and how disease spreadsPlant diseases and human infections (named examples)Reducing spread: hygiene, isolation, plant control measuresWhite blood cells and platelets: how they protect the bodyNon-specific defences (skin, mucus, stomach acid)Vaccination: how vaccines work and why they’re usedAntibiotics, antivirals and antiseptics (what each is for)Developing new medicines: preclinical and clinical testingLifestyle factors and disease risk (smoking, diet, exercise, alcohol)
Solids, liquids and gases in the particle modelExplaining density using particlesExplaining diffusion using particlesGas pressure in terms of particle collisionsChanges of state and heating/cooling curvesInternal energy and temperature (what changes and why)Atomic structure: protons, neutrons and electronsIsotopes and relative atomic massElectronic structure (simple shell model)The Periodic Table: periods and groupsMetals vs non-metals: typical physical propertiesUsing atomic structure to explain simple reactivity patterns
Elements, compounds and mixtures: clear definitionsPure substances and impuritiesFiltration, crystallisation and simple distillationFractional distillation (separating liquids)Paper/TLC chromatography: how separation worksReading chromatograms and calculating Rf valuesChoosing the best separation technique for a substanceIonic bonding: electron transfer and ion formationCovalent bonding: sharing electrons and moleculesMetallic bonding: why metals conduct and are malleableGiant ionic structures vs simple molecular substancesPolymers: repeating units and basic propertiesMaterials: ceramics, polymers, composites and alloys (uses)
Writing word equations and balancing symbol equationsConservation of mass (reactants vs products)Exothermic and endothermic reactionsReaction profiles (energy changes)Acids and alkalis: pH and neutralisationMaking salts (including crystallisation of a soluble salt)Reactivity series of metals (patterns and uses)Displacement reactions (metal and halogen examples)Oxidation and reduction (electron/oxygen ideas at GCSE level)Electrolysis: what it is and why ions matterElectrolysis of molten ionic compounds (products at electrodes)Electrolysis of aqueous solutions (how products are chosen)
Using the Periodic Table to predict chemical behaviourGroup 1 metals: reaction patterns (water and oxygen)Group 7 halogens: reaction patterns and displacementNoble gases: why they’re unreactiveNaming key compounds from formulas (basic GCSE set)Identifying ions with flame tests and simple precipitation testsIdentifying gases (hydrogen, oxygen, carbon dioxide, chlorine)Using tests to identify unknown substances in exam questionsUsing observations to infer reaction type
Collision theory: why reactions happen at different speedsMeasuring rate: gas volume, mass change, precipitationFactors affecting rate: temperature, concentration, surface areaCatalysts and enzymes (comparing role as catalysts)Interpreting rate graphs (tangent/gradient ideas)Reversible reactions and dynamic equilibriumLe Chatelier’s principle (temperature, pressure, concentration)Equilibrium in industrial processes (Haber process context)Yield, atom economy and sustainability links
Finite resources and sustainable chemistry choicesLife-cycle assessments: what they include and why they matterRecycling: benefits, limitations and real-world trade-offsCrude oil as a resource and why it’s usefulFractional distillation of crude oil: fractions and usesCracking hydrocarbons: conditions and productsAlkanes and the homologous series (patterns in formulas)Polymer production and environmental impactsEarth’s atmosphere: changes over time (GCSE narrative)Greenhouse effect vs climate change (separating ideas clearly)Human activity and atmospheric composition (evidence-based links)Potable water production and wastewater treatment (core stages)
Particle model in physics (motion and spacing)Density: measuring, calculating, and interpreting resultsPressure in fluids (qualitative + simple calculations)Moments and turning effect in everyday contexts (if assessed in suite questions)Changes of state: melting, boiling, evaporation, condensationLatent heat and why temperature stays constant during change of stateHeating curves: reading and sketching from dataGas pressure and temperature/volume trends (basic model)
Distance, time and speed: core definitionsUsing distance–time graphsVelocity and acceleration (what they mean)Using velocity–time graphs (including distance from area)Calculating acceleration from data/graphsNewton’s first law: inertia and balanced forcesNewton’s second law: force, mass and accelerationNewton’s third law: action–reaction pairsWeight, mass and gravitational field strengthFriction, drag and terminal velocityStopping distance: thinking and braking distance factorsHooke’s law and spring extensionWork done by a force and energy transfer in motion
Static charge: build-up, attraction and dischargeCurrent as rate of flow of chargePotential difference and what it representsSeries circuits: current, potential difference and resistance rulesParallel circuits: current splitting and shared potential differenceResistance and the I = V/R relationshipMeasuring current and potential difference correctlyI–V characteristics for ohmic conductors and non-ohmic componentsPower in electrical devices (power, energy and time links)Mains electricity safety: live, neutral, earth, fusesMagnets and magnetic fields (field lines and poles)Electromagnets: making and strengthening themUsing electromagnets in real devices (relays, motors context)
Transverse vs longitudinal wavesDescribing waves: amplitude, wavelength, frequency, periodThe wave equation and basic calculationsReflection and refraction (ray ideas and wave speed changes)Sound waves: pitch, volume and oscilloscopes (core interpretation)Electromagnetic spectrum: order and key usesHazards and safety with different EM wavesRadioactivity: what it is and why nuclei are unstableAlpha, beta and gamma: properties and penetrationIrradiation vs contaminationHalf-life (interpreting graphs and simple calculations)Background radiation and risk
Energy stores and pathways (transfers)Conservation of energy and Sankey diagramsWork done as energy transferredKinetic and gravitational potential energy calculationsElastic potential energy in springs (GCSE calculation focus)Power: what it means and how to calculate itEfficiency and why no process is 100% efficientWays to improve efficiency in everyday systemsEnergy resources: comparing reliability and environmental impact
Physics on the move: forces and energy in transportReducing unwanted energy transfers in vehiclesBraking and safety features explained with forces/energy ideasPowering Earth: how electricity is generatedNon-renewable vs renewable resources: pros and consNational and local issues: demand, reliability and costTransformers (core idea: stepping voltage up/down)Transmission efficiency and why high voltage is usedStoring energy from renewables (batteries, pumped storage context)
Lab safety: hazards, risks and control measuresWriting a clear method that can be repeatedIdentifying independent, dependent and control variablesAccuracy, precision, repeatability and reproducibilityEstimating uncertainty and spotting anomalous resultsRecording data in suitable tables (headings, units, resolution)Drawing graphs correctly (scales, labels, best-fit lines)Interpreting gradients and areas where relevantSampling techniques and using means appropriatelyRequired apparatus and techniquesPlanning and evaluating practical investigations (improvements and limitations)Linking practical methods to exam questions (methods, variables, calculations, conclusions)
