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GCSEEdexcel
Biology
Exam Questions
Animal cell organelles and what they doNewPlant cell organelles and what they doNewBacterial cell structure (prokaryotes) vs eukaryotesNewComparing animal, plant and bacterial cellsNewSpecialised cells and how structure links to functionNewLevels of organisation in multicellular organisms (cells → tissues → organs → systems)NewUsing SI units and prefixes in biology (milli, micro, nano, pico)NewEstimating cell size and scale (orders of magnitude)NewLight microscopes: uses, limits and what you can seeNewElectron microscopes: why they give more detailNewCore Practical: Using a microscope to observe specimens and produce labelled scientific drawingsNewCalculating magnification, image size and real sizeNewUsing scale bars correctlyNewEnzymes as biological catalystsNewThe active site model (lock-and-key / induced fit idea at GCSE level)NewEnzyme specificity (why one enzyme fits one substrate)NewEffects of temperature on enzyme activityNewEffects of pH on enzyme activityNewEffects of substrate concentration on enzyme activityNewCore Practical: Investigating the effect of pH on enzyme activityNewInterpreting enzyme graphs and identifying optimum conditionsNewCalculating rates in enzyme experimentsNewDiffusion: definition and examples in cellsNewFactors affecting rate of diffusion (concentration gradient, surface area, distance, temperature)NewOsmosis: definition and why it’s specialNewOsmosis in animal vs plant cells (turgid, plasmolysed, lysed)NewActive transport: definition and where cells use itNewComparing diffusion, osmosis and active transportNewCore Practical: Investigating osmosis in potato cylindersNewCalculating percentage change in mass for osmosis dataNewFood tests: starch (iodine)NewFood tests: reducing sugars (Benedict’s)NewFood tests: proteins (biuret)NewFood tests: fats (ethanol emulsion test)NewCore Practical: Using chemical reagents to identify biological moleculesNewEnergy content in food (simple calorimetry) and evaluating limitationsNew
The cell cycle overview (growth, DNA replication, division)NewInterphase: what happens and why it mattersNewMitosis stage-by-stage: prophaseNewMitosis stage-by-stage: metaphaseNewMitosis stage-by-stage: anaphaseNewMitosis stage-by-stage: telophaseNewCytokinesis and forming daughter cellsNewChromosomes, DNA and why daughter cells are genetically identicalNewWhy mitosis is needed for growth and repairNewMitosis in asexual reproductionNewCancer as uncontrolled cell divisionNewGrowth in animals: cell division and differentiationNewGrowth in plants: cell division, elongation and differentiationNewCell differentiation and specialised cellsNewUsing percentile charts to monitor human growthNewEmbryonic stem cells: what they are and what they can doNewAdult stem cells and plant meristemsNewStem cells in medicine: potential benefitsNewStem cells in medicine: risks and ethical issuesNewBrain regions: cerebrum, cerebellum and medulla oblongataNewCT scans: how they help study the brainNewPET scans: how they help study brain functionNewLimits of treating brain and nervous system damage (spinal injuries, brain tumours)NewNeurones: sensory, relay and motor (structures and roles)NewSynapses and neurotransmitters (how signals cross gaps)NewThe reflex arc step-by-stepNewThe eye: cornea and lens (focusing)NewThe eye: iris and pupil (controlling light entry)NewThe eye: retina, rod cells and cone cellsNewEye defects: cataractsNewEye defects: long-sightedness and short-sightednessNewEye defects: colour blindnessNewCorrecting vision defects (lenses and cataract treatment)New
Asexual reproduction: advantages and disadvantagesNewSexual reproduction: advantages and disadvantagesNewMeiosis: what it produces and why it creates variationNewHaploid vs diploid and what gametes areNewDNA as a polymer and why it’s called a polymerNewThe double helix and complementary base pairingNewNucleotides: sugar-phosphate backbone and basesNewGenome vs gene (clear definitions)NewExtracting DNA from fruit (method and why each step works)NewThe genetic code: base order → amino acid orderNewProtein folding and why shape matters (enzyme shape)NewTranscription: making mRNA from DNANewTranslation: using mRNA at ribosomes to build proteinsNewCodons and how triplets code for amino acidsNewtRNA and bringing amino acids to ribosomesNewNon-coding DNA variants: changing how much protein is madeNewCoding DNA variants: changing amino acid sequence and protein functionNewGregor Mendel’s work and why it was hard to accept at the timeNewAlleles as the reason inherited characteristics differNewKey inheritance terms (chromosome, gene, allele, genotype, phenotype, etc.)NewMonohybrid crosses using genetic diagramsNewPunnett squares: predicting offspring genotypes and phenotypesNewPedigree diagrams: tracking inheritance in familiesNewSex determination (XX/XY) using genetic diagramsNewCalculating inheritance outcomes (ratios, percentages, probability)NewABO blood groups: codominance and multiple allelesNewSex-linked genetic disorders: how inheritance worksNewPolygenic inheritance (why most traits aren’t single-gene)NewCauses of variation: genetic vs environmentalNewHuman Genome Project: outcomes and medical applicationsNewGenetic variation in populations and mutation as the sourceNewMutation effects: no effect, small effect, rare large effectsNew
Darwin and Wallace: what they contributed and why it matteredNewNatural selection: variation within populationsNewNatural selection: competition and selection pressuresNewNatural selection: survival and reproduction (fitness)NewNatural selection: inheritance and how traits spreadNewResistant organisms as evidence for evolution (antibiotic resistance)NewFossil evidence for human evolution: ArdiNewFossil evidence for human evolution: LucyNewFossil evidence for human evolution: Leakey’s 1.6 million-year-old fossilsNewEvidence from stone tools: how tools changed over timeNewDating stone tools using their environment (context evidence)NewPentadactyl limbs as evidence for evolution (homologous structures)NewClassification: why genetic analysis supports three domainsNewSelective breeding: how humans change populationsNewTissue culture: how it works and why it’s usefulNewTissue culture in medical research and plant breedingNewGenetic engineering: what it means (changing the genome)NewGenetic engineering: restriction enzymes and cutting DNANewGenetic engineering: sticky ends and matching DNA fragmentsNewGenetic engineering: ligase and joining DNANewGenetic engineering: vectors and transferring genesNewGM crops example: Bt gene for insect resistanceNewPros and cons of GM organisms (including ethics)NewFertilisers: boosting yields and potential drawbacksNewBiological control: how it works and risksNewWeighing benefits and risks of selective breeding and genetic engineering (agriculture + medicine)New
Health as physical, mental and social wellbeing (WHO definition in context)NewCommunicable vs non-communicable diseaseNewHow one disease can increase susceptibility to othersNewPathogens: viruses, bacteria, fungi and protistsNewCholera: cause, symptoms and transmission routeNewTuberculosis: cause, symptoms and airborne spreadNewChalara ash dieback: impact and spreadNewMalaria: protist disease and vector transmissionNewHIV: effect on immune system and AIDSNewStomach ulcers and Helicobacter (separate science)NewEbola: key features and spread via body fluids (separate science)NewReducing spread: hygiene, sanitation, isolation and vaccination (applied to examples)NewViral lifecycles: lytic pathwayNewViral lifecycles: lysogenic pathwayNewSTIs: how chlamydia spreads and how to reduce spreadNewSTIs: HIV spread and prevention strategiesNewPlant defences: physical barriers (cuticle, cell wall)NewPlant defences: chemical defences and medicinal usesNewDetecting plant disease: field observation and diagnostic testingNewHuman physical barriers: skin, mucus and ciliaNewHuman chemical defences: lysozyme and stomach acidNewSpecific immune response: antigens and antibody productionNewMemory lymphocytes and the secondary immune responseNewVaccination using inactive pathogens (how it builds immunity)NewImmunisation: advantages, disadvantages and herd immunityNewWhy antibiotics treat bacterial infections but not viral infectionsNewAseptic technique in culturing microorganisms (incl. autoclaves and sterile tools)NewCore Practical: Effects of antiseptics/antibiotics/plant extracts on microbial culturesNewMeasuring inhibition zones and calculating areas (πr²)NewStages of developing new medicines (discovery → trials)NewPreclinical testing vs clinical testing (what each checks)NewProducing monoclonal antibodies (lymphocytes → hybridoma)NewUses of monoclonal antibodies: pregnancy testsNewUses of monoclonal antibodies: diagnosis and targeted treatmentNewAdvantages of monoclonals vs drugs/radiotherapy (targeting)NewNon-communicable disease as multi-factor (genes + lifestyle + environment)NewLifestyle: diet and exercise links to obesity and malnutrition (BMI)NewLifestyle: alcohol and liver diseaseNewLifestyle: smoking and cardiovascular diseaseNewTreating cardiovascular disease: medicationNewTreating cardiovascular disease: surgeryNewTreating cardiovascular disease: lifestyle change (evaluation)New
Photosynthetic organisms as producers and the start of biomassNewPhotosynthesis word equation and symbol equationNewPhotosynthesis as an endothermic reaction (energy in)NewLimiting factors: light intensityNewLimiting factors: carbon dioxide concentrationNewLimiting factors: temperatureNewInteractions between limiting factors (shifting the limiting factor)NewCore Practical: Effect of light intensity on photosynthesis rateNewInverse square law and light intensity vs distance (applied to photosynthesis)NewRoot hair cells: adaptations for absorptionNewXylem: structure and transporting water/mineral ionsNewPhloem: structure and transporting sucrose (needs energy)NewTranspiration: movement of water through the plantNewStomata and guard cells: structure and functionNewTranslocation: moving sugars around the plantNewLeaf structure: palisade layer, spongy mesophyll and air spacesNewLeaf structure: stomata distribution and gas exchangeNewLeaf structure: chloroplasts and light captureNewEnvironmental factors affecting water uptake (light, wind, temperature)NewRate calculations for transpiration (interpreting change over time)NewPlant adaptations to extreme environments (leaf size/shape, cuticle, stomata)NewAuxins and control of growthNewPhototropism: how auxin causes shoots to bend to lightNewGravitropism: how auxin causes roots/shoots responsesNewCommercial uses of auxins (weedkillers, rooting powders)NewCommercial uses of gibberellins (germination, flowering, seedless fruit)NewCommercial uses of ethene (fruit ripening)New
Endocrine system overview: hormones and target organsNewKey endocrine glands (pituitary, thyroid, pancreas, adrenal, ovaries, testes)NewAdrenaline and the fight-or-flight responseNewAdrenaline effects: heart rate, blood pressure and blood flow to musclesNewAdrenaline effects: raising blood glucose via glycogen → glucoseNewThyroxine and metabolic rateNewNegative feedback control using thyroxine (TRH, TSH, thyroxine loop)NewMenstrual cycle stages (uterus lining changes)NewOestrogen: roles in the menstrual cycleNewProgesterone: roles in the menstrual cycleNewFSH and LH: roles and ovulationNewHormone interactions controlling menstruation and uterus liningNewHormonal contraception: how it prevents pregnancyNewBarrier contraception: how it prevents pregnancyNewEvaluating hormonal vs barrier contraceptionNewFertility treatment hormones: IVF steps overviewNewClomifene therapy: how it works (stimulating ovulation)NewWhy a constant internal environment mattersNewHomeostasis overview: thermoregulation and osmoregulationNewThermoregulation: how temperature affects enzymesNewSkin structure for thermoregulation (dermis, epidermis)NewHypothalamus as the thermoregulatory control centreNewThermoregulation responses: shiveringNewThermoregulation responses: vasoconstriction and vasodilationNewBlood glucose control: insulin roleNewBlood glucose control: glucagon roleNewType 1 diabetes: cause and control methodsNewType 2 diabetes: cause and control methodsNewBMI and waist:hip calculations (linking data to diabetes risk)NewEvaluating the correlation between body mass and type 2 diabetesNewUrinary system structure (kidneys, ureters, bladder, urethra)NewNephron structure overview (Bowman’s capsule to collecting duct)NewFiltration at the glomerulus and Bowman’s capsuleNewSelective reabsorption of glucoseNewWater reabsorption and balancing water levelsNewADH and collecting duct permeabilityNewKidney failure treatments: dialysis vs transplantNewUrea formation from excess amino acids in the liverNew
Why organisms need transport systems (O₂, CO₂, nutrients, ions, water, urea)NewExchange surfaces: what they are and why they’re neededNewSurface area to volume ratio and its consequencesNewAlveoli adaptations for diffusion (large SA, short distance, blood supply)NewDiffusion rate factors in exchange (surface area, gradient, distance)NewUsing Fick’s law to calculate diffusion rate (separate science)NewBlood components: red blood cells and oxygen transportNewBlood components: white blood cells (phagocytes and lymphocytes)NewBlood components: plasma and what it carriesNewBlood components: platelets and clottingNewBlood vessels: arteries structure and functionNewBlood vessels: veins structure and functionNewBlood vessels: capillaries structure and functionNewHeart structure: chambers and valvesNewDouble circulatory system: pulmonary vs systemicNewWhy ventricle walls differ in thicknessNewCellular respiration: why cells need itNewAerobic respiration: reactants, products and energy releaseNewAnaerobic respiration: how it differs and when it happensNewComparing aerobic and anaerobic respirationNewCore Practical: Investigating respiration rate in living organismsNewHeart rate, stroke volume and cardiac output calculationsNewInterpreting exercise data for breathing rate and heart rateNew
Levels of organisation: organism to ecosystemNewAbiotic factors affecting communities (temperature, light, water, pollutants)NewBiotic factors affecting communities (competition, predation)NewInterdependence in communitiesNewParasitism and mutualism (with clear examples)NewCore Practical: Fieldwork using quadrats and belt transectsNewChoosing an appropriate sampling method (random vs along a gradient)NewCalculating means from field dataNewEstimating population size or abundance from quadrat dataNewUsing transect results to describe distribution patternsNewEnergy in ecosystems: producers, consumers and decomposersNewEnergy transfer losses at each trophic level (less useful forms)NewPyramids of biomass: what they show and why shapes differNewCalculating efficiency of energy transfer between trophic levelsNewHuman impacts: fish farming (benefits and harms)NewHuman impacts: non-indigenous species and biodiversityNewHuman impacts: eutrophication causes and effectsNewWhy biodiversity matters (local and global)NewConservation strategies and reforestation impactsNewFood security: population growth and demandNewFood security: meat consumption and land useNewFood security: pests, pathogens and environmental changeNewSustainability issues (biofuels, cost of inputs)NewMaterial cycles overview (abiotic ↔ biotic)NewCarbon cycle processes and the role of decomposersNewWater cycle processes and potable water production (incl. desalination)NewNitrogen cycle: nitrates, bacteria and plant uptakeNewFarming strategies: fertilisers and crop rotation (linked to nitrates)NewIndicator species for water pollution (clean vs polluted water)NewIndicator species for air quality (lichens, blackspot fungus)NewDecomposition: what it is and why it mattersNewDecomposition rate factors: temperature, water content, oxygenNewFood preservation explained using decomposition factorsNewComposting explained using decomposition factorsNewCalculating rate changes in decay of biological materialNew
