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GCSEOCR
Combined Science
Exam Questions
Cells as the basic unit of lifeNewPlant cells vs animal cells: key similarities and differencesNewProkaryotic cells vs eukaryotic cellsNewCell organelles and their functionsNewUsing a light microscope safely and correctlyNewPreparing slides and using stains to improve contrastNewCalculating magnification and image sizeNewComparing light and electron micrographs (what each can show)NewThe role of DNA in cells (genetic material as a code)NewProteins as biological molecules with specific functionsNewEnzymes as biological catalystsNewLock-and-key model and enzyme specificityNewFactors affecting enzyme activity: temperature, pH, substrate concentrationNew
What respiration is and why cells need itNewAerobic respiration: word equation and key ideasNewAnaerobic respiration in musclesNewAnaerobic respiration in microorganisms (fermentation basics)NewComparing aerobic vs anaerobic respiration (energy release)NewRespiration as an enzyme-controlled processNewUsing respiration ideas to explain exercise and recoveryNewInterpreting simple data about respiration rateNew
Photosynthesis as a chemical reaction in plantsNewThe word equation and what it meansNewChloroplasts and chlorophyll: where photosynthesis happensNewHow light intensity affects photosynthesisNewHow carbon dioxide concentration affects photosynthesisNewHow temperature affects photosynthesisNewLimiting factors and predicting the rate-limiting factorNewUsing glucose made in photosynthesis (storage and transport)NewLinking photosynthesis and respiration in ecosystemsNew
Diffusion: what it is and what affects the rateNewOsmosis: movement of water and partially permeable membranesNewActive transport: moving substances against a concentration gradientNewComparing diffusion, osmosis and active transportNewFrom cells to tissues to organs to organ systemsNewMitosis as cell division for growth and repairNewStem cells: what they are and why they matterNewExchange surfaces: what makes them efficientNewPlant transport tissues: xylem and phloem (what they carry)NewTranspiration basics and why plants lose waterNew
Surface area to volume ratio and why it mattersNewDiffusion distance and exchange efficiencyNewWhy multicellular organisms need transport systemsNewThe human circulatory system: overview and purposeNewDouble circulatory system in mammalsNewThe heart: chambers, valves and blood vesselsNewArteries, veins and capillaries: structure and functionNewBlood components: plasma, red cells, white cells and plateletsNewGas exchange in the lungs: structure and function of alveoliNewInterpreting circulatory/gas exchange data in exam-style questionsNew
The nervous system: CNS, sensory receptors and effectorsNewStimulus–response pathways and survival valueNewReflex actions and reflex arcsNewSynapses (simple model) and neurotransmittersNewThe endocrine system and hormone signallingNewComparing nervous vs hormonal controlNewHomeostasis: maintaining stable internal conditionsNewThermoregulation: sweating, shivering and blood flow changesNewBlood glucose control: insulin and glucagonNewDiabetes (type 1 and type 2 at GCSE level)NewKidneys and osmoregulation (water balance)NewNegative feedback as a control mechanismNew
What an ecosystem is (biotic and abiotic factors)NewLevels of organisation: organism to community to ecosystemNewFood chains and trophic levelsNewFood webs and interdependenceNewCompetition and predator–prey relationshipsNewPyramids of number, biomass and energyNewDecomposers and nutrient recyclingNewThe carbon cycleNewThe water cycleNewBiodiversity: what it means and why it mattersNewHuman impacts on ecosystems (habitat loss, pollution)New
DNA, genes and chromosomes: the big pictureNewGenetic terms: genotype, phenotype and allelesNewDominant and recessive inheritanceNewMonohybrid crosses using Punnett squaresNewInherited disorders (using clear examples)NewSex determination (XX/XY) and inheritance patternsNewVariation: genetic vs environmentalNewMutation as a source of new variationNewNatural selection: how it works, step by stepNewEvolution and adaptation (linking to survival and reproduction)NewSelective breeding: process, benefits and drawbacksNewAntibiotic resistance as an example of evolution in actionNew
Monitoring ecosystems and environmental changeNewPollution and biodiversity: causes and consequencesNewFood security: why feeding humans is challengingNewIncreasing food production: farming methods and trade-offsNewFertilisers and eutrophication (cause → effect chains)NewGenetic modification in crops: potential benefits and concernsNewHealth and disease: what the terms meanNewCommunicable vs non-communicable diseasesNewPathogens (virus, bacteria, protist, fungi) and how disease spreadsNewPlant diseases and human infections (named examples)NewReducing spread: hygiene, isolation, plant control measuresNewWhite blood cells and platelets: how they protect the bodyNewNon-specific defences (skin, mucus, stomach acid)NewVaccination: how vaccines work and why they’re usedNewAntibiotics, antivirals and antiseptics (what each is for)NewDeveloping new medicines: preclinical and clinical testingNewLifestyle factors and disease risk (smoking, diet, exercise, alcohol)New
Solids, liquids and gases in the particle modelNewExplaining density using particlesNewExplaining diffusion using particlesNewGas pressure in terms of particle collisionsNewChanges of state and heating/cooling curvesNewInternal energy and temperature (what changes and why)NewAtomic structure: protons, neutrons and electronsNewIsotopes and relative atomic massNewElectronic structure (simple shell model)NewThe Periodic Table: periods and groupsNewMetals vs non-metals: typical physical propertiesNewUsing atomic structure to explain simple reactivity patternsNew
Elements, compounds and mixtures: clear definitionsNewPure substances and impuritiesNewFiltration, crystallisation and simple distillationNewFractional distillation (separating liquids)NewPaper/TLC chromatography: how separation worksNewReading chromatograms and calculating Rf valuesNewChoosing the best separation technique for a substanceNewIonic bonding: electron transfer and ion formationNewCovalent bonding: sharing electrons and moleculesNewMetallic bonding: why metals conduct and are malleableNewGiant ionic structures vs simple molecular substancesNewPolymers: repeating units and basic propertiesNewMaterials: ceramics, polymers, composites and alloys (uses)New
Writing word equations and balancing symbol equationsNewConservation of mass (reactants vs products)NewExothermic and endothermic reactionsNewReaction profiles (energy changes)NewAcids and alkalis: pH and neutralisationNewMaking salts (including crystallisation of a soluble salt)NewReactivity series of metals (patterns and uses)NewDisplacement reactions (metal and halogen examples)NewOxidation and reduction (electron/oxygen ideas at GCSE level)NewElectrolysis: what it is and why ions matterNewElectrolysis of molten ionic compounds (products at electrodes)NewElectrolysis of aqueous solutions (how products are chosen)New
Using the Periodic Table to predict chemical behaviourNewGroup 1 metals: reaction patterns (water and oxygen)NewGroup 7 halogens: reaction patterns and displacementNewNoble gases: why they’re unreactiveNewNaming key compounds from formulas (basic GCSE set)NewIdentifying ions with flame tests and simple precipitation testsNewIdentifying gases (hydrogen, oxygen, carbon dioxide, chlorine)NewUsing tests to identify unknown substances in exam questionsNewUsing observations to infer reaction typeNew
Collision theory: why reactions happen at different speedsNewMeasuring rate: gas volume, mass change, precipitationNewFactors affecting rate: temperature, concentration, surface areaNewCatalysts and enzymes (comparing role as catalysts)NewInterpreting rate graphs (tangent/gradient ideas)NewReversible reactions and dynamic equilibriumNewLe Chatelier’s principle (temperature, pressure, concentration)NewEquilibrium in industrial processes (Haber process context)NewYield, atom economy and sustainability linksNew
Finite resources and sustainable chemistry choicesNewLife-cycle assessments: what they include and why they matterNewRecycling: benefits, limitations and real-world trade-offsNewCrude oil as a resource and why it’s usefulNewFractional distillation of crude oil: fractions and usesNewCracking hydrocarbons: conditions and productsNewAlkanes and the homologous series (patterns in formulas)NewPolymer production and environmental impactsNewEarth’s atmosphere: changes over time (GCSE narrative)NewGreenhouse effect vs climate change (separating ideas clearly)NewHuman activity and atmospheric composition (evidence-based links)NewPotable water production and wastewater treatment (core stages)New
Particle model in physics (motion and spacing)NewDensity: measuring, calculating, and interpreting resultsNewPressure in fluids (qualitative + simple calculations)NewMoments and turning effect in everyday contexts (if assessed in suite questions)NewChanges of state: melting, boiling, evaporation, condensationNewLatent heat and why temperature stays constant during change of stateNewHeating curves: reading and sketching from dataNewGas pressure and temperature/volume trends (basic model)New
Distance, time and speed: core definitionsNewUsing distance–time graphsNewVelocity and acceleration (what they mean)NewUsing velocity–time graphs (including distance from area)NewCalculating acceleration from data/graphsNewNewton’s first law: inertia and balanced forcesNewNewton’s second law: force, mass and accelerationNewNewton’s third law: action–reaction pairsNewWeight, mass and gravitational field strengthNewFriction, drag and terminal velocityNewStopping distance: thinking and braking distance factorsNewHooke’s law and spring extensionNewWork done by a force and energy transfer in motionNew
Static charge: build-up, attraction and dischargeNewCurrent as rate of flow of chargeNewPotential difference and what it representsNewSeries circuits: current, potential difference and resistance rulesNewParallel circuits: current splitting and shared potential differenceNewResistance and the I = V/R relationshipNewMeasuring current and potential difference correctlyNewI–V characteristics for ohmic conductors and non-ohmic componentsNewPower in electrical devices (power, energy and time links)NewMains electricity safety: live, neutral, earth, fusesNewMagnets and magnetic fields (field lines and poles)NewElectromagnets: making and strengthening themNewUsing electromagnets in real devices (relays, motors context)New
Transverse vs longitudinal wavesNewDescribing waves: amplitude, wavelength, frequency, periodNewThe wave equation and basic calculationsNewReflection and refraction (ray ideas and wave speed changes)NewSound waves: pitch, volume and oscilloscopes (core interpretation)NewElectromagnetic spectrum: order and key usesNewHazards and safety with different EM wavesNewRadioactivity: what it is and why nuclei are unstableNewAlpha, beta and gamma: properties and penetrationNewIrradiation vs contaminationNewHalf-life (interpreting graphs and simple calculations)NewBackground radiation and riskNew
Energy stores and pathways (transfers)NewConservation of energy and Sankey diagramsNewWork done as energy transferredNewKinetic and gravitational potential energy calculationsNewElastic potential energy in springs (GCSE calculation focus)NewPower: what it means and how to calculate itNewEfficiency and why no process is 100% efficientNewWays to improve efficiency in everyday systemsNewEnergy resources: comparing reliability and environmental impactNew
Physics on the move: forces and energy in transportNewReducing unwanted energy transfers in vehiclesNewBraking and safety features explained with forces/energy ideasNewPowering Earth: how electricity is generatedNewNon-renewable vs renewable resources: pros and consNewNational and local issues: demand, reliability and costNewTransformers (core idea: stepping voltage up/down)NewTransmission efficiency and why high voltage is usedNewStoring energy from renewables (batteries, pumped storage context)New
Lab safety: hazards, risks and control measuresNewWriting a clear method that can be repeatedNewIdentifying independent, dependent and control variablesNewAccuracy, precision, repeatability and reproducibilityNewEstimating uncertainty and spotting anomalous resultsNewRecording data in suitable tables (headings, units, resolution)NewDrawing graphs correctly (scales, labels, best-fit lines)NewInterpreting gradients and areas where relevantNewSampling techniques and using means appropriatelyNewRequired apparatus and techniquesNewPlanning and evaluating practical investigations (improvements and limitations)NewLinking practical methods to exam questions (methods, variables, calculations, conclusions)New
