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Characteristics of Living Organisms
1Characteristics of Living OrganismsRead next2Nutrition as a Characteristic of LifeRead next3Respiration as a Characteristic of LifeRead next4Excretion as a Characteristic of LifeRead next5Response to SurroundingsRead next6Movement as a Characteristic of LifeRead next7Control of Internal ConditionsRead next8Reproduction as a Characteristic of LifeRead next9Growth and DevelopmentRead next10Eukaryotic Organisms: PlantsRead next11Eukaryotic Organisms: AnimalsRead next12Eukaryotic Organisms: FungiRead next13Eukaryotic Organisms: ProtoctistsRead next14Prokaryotic Organisms: BacteriaRead next15Structure and Features of BacteriaRead next16Examples of BacteriaRead next17Definition of PathogensRead next18Pathogens: FungiRead next19Pathogens: BacteriaRead next20Pathogens: ProtoctistsRead next21Pathogens: VirusesRead next22Structure and Features of VirusesRead next23Examples of VirusesRead next24Tobacco Mosaic Virus and Plant DiseaseRead next25Influenza Virus and Human DiseaseRead next26HIV Virus and AIDSRead next
Levels of Organisation in Organisms
1Levels of Organisation in OrganismsRead next2The Nucleus and Its FunctionsRead next3The Cytoplasm and Its RoleRead next4Cell Membrane Structure and FunctionRead next5The Cell Wall in PlantsRead next6Mitochondria and Energy ProductionRead next7Chloroplasts and PhotosynthesisRead next8Ribosomes and Protein SynthesisRead next9The Vacuole in Plant CellsRead next10Comparing Plant and Animal CellsRead next11Cell Differentiation and Specialised CellsRead next12Uses of Stem Cells in MedicineRead next13Chemical Elements in Biological MoleculesRead next14Structure of CarbohydratesRead next15Structure of Proteins and LipidsRead next16Testing for Glucose, Starch, Protein, and FatRead next17Enzymes as Biological CatalystsRead next18Effect of Temperature on Enzyme FunctionRead next19Effect of pH on Enzyme FunctionRead next20Diffusion in CellsRead next21Osmosis in CellsRead next22Active Transport in CellsRead next23Factors Affecting Substance MovementRead next24Investigating Diffusion and OsmosisRead next25Photosynthesis Process and ImportanceRead next26Photosynthesis Word and Chemical EquationsRead next27Factors Affecting Photosynthesis RateRead next28Leaf Structure and Adaptations for PhotosynthesisRead next29Mineral Ions Needed for Plant GrowthRead next30Investigating Photosynthesis in PlantsRead next31Components of a Balanced Human DietRead next32Functions of Nutrients in Human DietRead next33Energy Requirements in HumansRead next34Structure of the Human Alimentary CanalRead next35Peristalsis and Food Movement in the GutRead next36Role of Digestive EnzymesRead next37Bile Production and StorageRead next38Functions of Bile in DigestionRead next39Adaptations of the Small Intestine for AbsorptionRead next40Investigating Energy Content in Food SamplesRead next41ATP Production in RespirationRead next42Aerobic vs Anaerobic RespirationRead next43Equations for Aerobic and Anaerobic RespirationRead next44Investigating Respiration in Living OrganismsRead next45Diffusion in Plant Gas ExchangeRead next46Gas Exchange in Photosynthesis and RespirationRead next47Leaf Adaptations for Gas ExchangeRead next48Role of Stomata in Gas ExchangeRead next49Net Gas Exchange and Light IntensityRead next50Investigating Light Effects on Gas ExchangeRead next51Structure of the Human ThoraxRead next52Role of Intercostal Muscles and DiaphragmRead next53Alveoli Adaptations for Gas ExchangeRead next54Biological Consequences of SmokingRead next55Investigating Human Breathing and Exercise EffectsRead next
Understanding Diffusion
1Understanding DiffusionRead next2Examples of Diffusion in CellsRead next3Understanding OsmosisRead next4Osmosis in Plant and Animal CellsRead next5Practical: Investigating Osmosis in Living SystemsRead next6Understanding Active TransportRead next7Examples of Active Transport in CellsRead next8Comparing Diffusion, Osmosis, and Active TransportRead next9Surface Area to Volume Ratio and Substance MovementRead next10Effect of Surface Area on Diffusion RateRead next11Distance and Its Effect on Diffusion RateRead next12Temperature and Its Effect on Diffusion RateRead next13Concentration Gradient and Its Effect on Diffusion RateRead next14Practical: Investigating Diffusion in Non-Living SystemsRead next15Practical: Investigating Diffusion in Living SystemsRead next16Practical: Investigating Osmosis in Non-Living SystemsRead next17Role of Semi-Permeable Membranes in OsmosisRead next18Importance of Osmosis in PlantsRead next19Importance of Osmosis in AnimalsRead next20Energy Requirements in Active TransportRead next21Role of Carrier Proteins in Active TransportRead next22Examining Real-Life Applications of Active TransportRead next23Common Misconceptions in Diffusion, Osmosis, and Active TransportRead next24Practical Skills: Designing Experiments for DiffusionRead next25Practical Skills: Designing Experiments for OsmosisRead next26Practical Skills: Designing Experiments for Active TransportRead next27Data Analysis: Graphing Diffusion RatesRead next28Data Analysis: Osmosis Experiment ResultsRead next29Interpreting Experimental Errors in Diffusion and OsmosisRead next30Adaptations of Cells for Efficient Substance MovementRead next31Role of Cell Membranes in Substance MovementRead next32Using Models to Demonstrate Diffusion and OsmosisRead next33Factors Limiting Diffusion in Multicellular OrganismsRead next34Transport Mechanisms in Unicellular OrganismsRead next35Diffusion and Osmosis in Everyday LifeRead next36Exam Practice: Diffusion QuestionsRead next37Exam Practice: Osmosis QuestionsRead next38Exam Practice: Active Transport QuestionsRead next39Understanding Hypotonic, Hypertonic, and Isotonic SolutionsRead next40Effects of Hypotonic Solutions on Animal CellsRead next41Effects of Hypertonic Solutions on Plant CellsRead next42Practical: Investigating Turgor in Plant CellsRead next43Role of Energy in Cellular Transport ProcessesRead next44Linking Movement of Substances to Cell FunctionRead next45Examining the Role of Diffusion in RespirationRead next46Using Mathematical Models to Predict Diffusion RatesRead next47How Environmental Conditions Impact Diffusion and OsmosisRead next48Practical: Investigating Factors Affecting Diffusion RatesRead next49Exam Tips: Common Traps in Movement of Substances QuestionsRead next
Definition of Photosynthesis
1Definition of PhotosynthesisRead next2Word and Symbol Equations for PhotosynthesisRead next3Light Energy to Chemical Energy ConversionRead next4Factors Affecting PhotosynthesisRead next5Structure of a Leaf for PhotosynthesisRead next6Mineral Ions in Plant GrowthRead next7Magnesium Ions and ChlorophyllRead next8Nitrate Ions and Amino AcidsRead next9Practical: Investigating Photosynthesis with Water PlantsRead next10Practical: Starch Production in PhotosynthesisRead next11Practical: Light, CO2, and Chlorophyll in PhotosynthesisRead next12Components of a Balanced Human DietRead next13Sources of Nutrients in the DietRead next14Functions of Nutrients in the DietRead next15Energy Requirements and Lifestyle FactorsRead next16Structure of the Human Alimentary CanalRead next17Functions of the Alimentary Canal OrgansRead next18The Process of PeristalsisRead next19Role of Amylase and Maltase in Starch DigestionRead next20Role of Proteases in Protein DigestionRead next21Role of Lipases in Lipid DigestionRead next22Production and Storage of BileRead next23Role of Bile in DigestionRead next24Adaptations of the Small Intestine for AbsorptionRead next25Structure and Function of a VillusRead next26Practical: Measuring Energy Content in FoodRead next27Common Exam Traps in Photosynthesis QuestionsRead next28Common Exam Traps in Digestion QuestionsRead next
Definition of Respiration
1Definition of RespirationRead next2The Role of ATP in RespirationRead next3The Process of Aerobic RespirationRead next4Word Equation for Aerobic RespirationRead next5Balanced Chemical Equation for Aerobic RespirationRead next6The Process of Anaerobic Respiration in AnimalsRead next7Word Equation for Anaerobic Respiration in AnimalsRead next8The Process of Anaerobic Respiration in PlantsRead next9Word Equation for Anaerobic Respiration in PlantsRead next10Comparison of Aerobic and Anaerobic RespirationRead next11Practical: Investigating Carbon Dioxide Evolution in RespirationRead next12Practical: Investigating Heat Production in RespirationRead next13Definition of Gas ExchangeRead next14The Role of Diffusion in Gas ExchangeRead next15Gas Exchange in Flowering PlantsRead next16Gas Exchange in Relation to Photosynthesis and RespirationRead next17Leaf Structure Adaptations for Gas ExchangeRead next18The Role of Stomata in Gas ExchangeRead next19Net Gas Exchange and Light IntensityRead next20Practical: Effect of Light on Net Gas Exchange Using Hydrogen-Carbonate IndicatorRead next21Structure of the Human ThoraxRead next22The Role of the Diaphragm in VentilationRead next23The Role of Intercostal Muscles in VentilationRead next24The Process of Inhalation and ExhalationRead next25Alveoli Adaptations for Gas ExchangeRead next26The Role of Capillaries in Gas ExchangeRead next27Biological Consequences of Smoking on the LungsRead next28Biological Consequences of Smoking on the Circulatory SystemRead next29Coronary Heart Disease and SmokingRead next30Practical: Investigating Human Breathing and Carbon Dioxide ReleaseRead next31Practical: Effect of Exercise on Breathing RateRead next
Diffusion in Unicellular Organisms
1Diffusion in Unicellular OrganismsRead next2Why Multicellular Organisms Need Transport SystemsRead next3The Role of Xylem in PlantsRead next4The Role of Phloem in PlantsRead next5Water Absorption by Root Hair CellsRead next6Understanding Transpiration in PlantsRead next7Factors Affecting Transpiration RateRead next8Practical: Investigating Transpiration RatesRead next9Composition of Blood ComponentsRead next10Role of Plasma in TransportRead next11Adaptations of Red Blood Cells for Oxygen TransportRead next12Phagocytes and Pathogen IngestionRead next13Lymphocytes and Antibody ProductionRead next14How Vaccination Creates Memory CellsRead next15Platelets and Blood ClottingRead next16Structure and Function of the Human HeartRead next17Changes in Heart Rate During ExerciseRead next18Effect of Adrenaline on Heart RateRead next19Risk Factors for Coronary Heart DiseaseRead next20Structure and Function of ArteriesRead next21Structure and Function of VeinsRead next22Structure and Function of CapillariesRead next23Overview of the Human Circulatory SystemRead next24Blood Vessels to and from the HeartRead next25Blood Vessels to and from the LungsRead next26Blood Vessels to and from the LiverRead next27Blood Vessels to and from the KidneysRead next
Definition of Excretion
1Definition of ExcretionRead next2Importance of Excretion in OrganismsRead next3Metabolic Waste Products in PlantsRead next4Excretion of Oxygen in PlantsRead next5Excretion of Carbon Dioxide in PlantsRead next6Role of Stomata in Plant ExcretionRead next7Excretion in Humans: OverviewRead next8Organs of Excretion in HumansRead next9Excretory Products of the LungsRead next10Excretory Products of the SkinRead next11Excretory Products of the KidneysRead next12Structure of the Human Urinary SystemRead next13Function of the Kidneys in ExcretionRead next14Structure of a NephronRead next15Role of the Bowman’s Capsule and GlomerulusRead next16Process of Ultrafiltration in the KidneysRead next17Formation of Glomerular FiltrateRead next18Selective Reabsorption in the Proximal Convoluted TubuleRead next19Role of the Loop of Henle in Water ReabsorptionRead next20Function of the Collecting Duct in Water ReabsorptionRead next21Role of ADH in Water RegulationRead next22Composition of UrineRead next23Osmoregulation: Definition and ImportanceRead next24Role of the Kidneys in OsmoregulationRead next25Control of Blood Water Content by ADHRead next26Adaptations of the Kidney for Excretion and OsmoregulationRead next27Comparison of Excretion in Plants and HumansRead next28Effects of Kidney Failure on ExcretionRead next29Kidney Dialysis: Process and PurposeRead next30Kidney Transplants: Advantages and ChallengesRead next31Common Disorders of the Excretory SystemRead next32Practical: Investigating Stomata and Gas Exchange in PlantsRead next33Practical: Investigating Urine CompositionRead next34Exam Trap: Misunderstanding the Role of StomataRead next35Exam Trap: Confusing Ultrafiltration and ReabsorptionRead next36Exam Trap: Misinterpreting Osmoregulation ProcessesRead next
What is a Stimulus?
1What is a Stimulus?Read next2The Role of ReceptorsRead next3The Role of EffectorsRead next4Stimulus-Response PathwayRead next5Introduction to HomeostasisRead next6Examples of Homeostasis in HumansRead next7Components of a Coordinated ResponseRead next8The Nervous System OverviewRead next9Structure of the Central Nervous SystemRead next10Role of the Brain and Spinal CordRead next11Structure and Function of NeuronsRead next12Sensory Neurons and Their FunctionRead next13Motor Neurons and Their FunctionRead next14Relay Neurons and Their FunctionRead next15The Role of SynapsesRead next16Neurotransmitters and Signal TransmissionRead next17Structure of a Reflex ArcRead next18Reflex Actions: Examples and ImportanceRead next19The Endocrine System OverviewRead next20Differences Between Nervous and Hormonal ControlRead next21Hormones and Their Roles in the BodyRead next22Adrenaline: Source, Role, and EffectsRead next23Insulin: Source, Role, and EffectsRead next24Testosterone: Source, Role, and EffectsRead next25Oestrogen and Progesterone: Sources and RolesRead next26FSH and LH: Sources and RolesRead next27ADH: Source, Role, and EffectsRead next28The Role of the Skin in Temperature RegulationRead next29Sweating and Body Temperature ControlRead next30Vasoconstriction and VasodilationRead next31The Role of Plants in Responding to StimuliRead next32Phototropism in PlantsRead next33Geotropism in Roots and ShootsRead next34Role of Auxins in Plant ResponsesRead next35The Importance of Tropisms for Plant SurvivalRead next36Investigating the Effect of Light on Plant GrowthRead next37Investigating the Effect of Gravity on Plant GrowthRead next38Introduction to ThermoregulationRead next39Body Water Content RegulationRead next40The Role of Hormones in HomeostasisRead next41Common Exam Mistakes in Coordination and ResponseRead next42Interpreting Nervous System DiagramsRead next43Interpreting Hormonal Pathways in HumansRead next44Examining Plant Growth ExperimentsRead next45Applying Homeostasis to Real-Life ScenariosRead next46Comparing Nervous and Hormonal ResponsesRead next47Understanding Feedback MechanismsRead next48Negative Feedback in HomeostasisRead next49Positive Feedback: Examples and EffectsRead next50Practical: Investigating Reaction TimesRead next
Definition of Sexual Reproduction
1Definition of Sexual ReproductionRead next2Definition of Asexual ReproductionRead next3Differences Between Sexual and Asexual ReproductionRead next4Advantages and Disadvantages of Sexual ReproductionRead next5Advantages and Disadvantages of Asexual ReproductionRead next6Fertilisation: Definition and ProcessRead next7Formation and Development of a ZygoteRead next8Structure of Insect-Pollinated FlowersRead next9Adaptations of Insect-Pollinated FlowersRead next10Structure of Wind-Pollinated FlowersRead next11Adaptations of Wind-Pollinated FlowersRead next12Pollination: Process and TypesRead next13Growth of the Pollen Tube and Fertilisation in PlantsRead next14Seed and Fruit Formation in PlantsRead next15Conditions for Seed GerminationRead next16Practical: Investigating Seed Germination ConditionsRead next17Food Reserves in Germinating SeedsRead next18Natural Asexual Reproduction in Plants (Runners)Read next19Artificial Asexual Reproduction in Plants (Cuttings)Read next20Structure of the Male Reproductive SystemRead next21Structure of the Female Reproductive SystemRead next22Functions of Male Reproductive OrgansRead next23Functions of Female Reproductive OrgansRead next24Role of Oestrogen in the Menstrual CycleRead next25Role of Progesterone in the Menstrual CycleRead next26Role of FSH in the Menstrual CycleRead next27Role of LH in the Menstrual CycleRead next28Fertilisation and Early Embryo Development in HumansRead next29Role of the Placenta in Embryo NutritionRead next30Protection of the Developing Embryo by Amniotic FluidRead next31Role of Oestrogen in Secondary Sexual CharacteristicsRead next32Role of Testosterone in Secondary Sexual CharacteristicsRead next
Differences Between Sexual and Asexual Reproduction
1Differences Between Sexual and Asexual ReproductionRead next2Fusion of Gametes in FertilisationRead next3Structure and Adaptations of Insect-Pollinated FlowersRead next4Structure and Adaptations of Wind-Pollinated FlowersRead next5Growth of Pollen Tube and FertilisationRead next6Conditions Needed for Seed GerminationRead next7Food Reserves in Germinating SeedsRead next8Natural and Artificial Methods of Asexual Reproduction in PlantsRead next9Structure of Male and Female Reproductive SystemsRead next10Roles of Oestrogen and Progesterone in the Menstrual CycleRead next11Roles of FSH and LH in the Menstrual CycleRead next12Placenta and Embryo NutritionRead next13Amniotic Fluid and Embryo ProtectionRead next14Roles of Oestrogen and Testosterone in Secondary Sexual CharacteristicsRead next15Definition of Genome and GeneRead next16Chromosomes and Genes in the NucleusRead next17Structure of DNA: Double Helix and Base PairingRead next18Structure of RNA and Differences from DNARead next19Stages of Protein Synthesis: Transcription and TranslationRead next20Roles of mRNA, Ribosomes, tRNA, Codons, and AnticodonsRead next21Definition of Alleles and Their Role in Inherited CharacteristicsRead next22Dominant, Recessive, Homozygous, Heterozygous, Phenotype, and GenotypeRead next23Understanding CodominanceRead next24Polygenic Inheritance vs Single Gene InheritanceRead next25Monohybrid Inheritance and Genetic DiagramsRead next26Interpreting Family PedigreesRead next27Predicting Probabilities in Monohybrid CrossesRead next28Sex Determination by ChromosomesRead next29Sex Determination Using Genetic DiagramsRead next30Mitosis and Production of Identical CellsRead next31Roles of Mitosis in Growth, Repair, Cloning, and Asexual ReproductionRead next32Meiosis and Formation of Haploid GametesRead next33Genetic Variation from Random FertilisationRead next34Diploid and Haploid Chromosome Numbers in HumansRead next35Genetic, Environmental, and Combined VariationRead next36Definition and Inheritance of MutationRead next37Impact of DNA Changes on PhenotypeRead next38Effects of Genetic Mutations on PhenotypeRead next39Factors Increasing Mutation RatesRead next40Darwin’s Theory of Evolution by Natural SelectionRead next41Antibiotic Resistance in Bacterial PopulationsRead next
Understanding Populations, Communities, Habitats, and Ecosystems
1Understanding Populations, Communities, Habitats, and EcosystemsRead next2Investigating Population Size with QuadratsRead next3Understanding BiodiversityRead next4Measuring Biodiversity with QuadratsRead next5Abiotic Factors Affecting Population SizeRead next6Biotic Factors Affecting Population SizeRead next7Producers and Their Role in EcosystemsRead next8Primary, Secondary, and Tertiary ConsumersRead next9Decomposers and Their Role in EcosystemsRead next10Understanding Food Chains and Food WebsRead next11Constructing Pyramids of NumberRead next12Understanding Pyramids of BiomassRead next13Exploring Pyramids of Energy TransferRead next14Energy Transfer Efficiency in Food ChainsRead next15Stages of the Carbon CycleRead next16Processes of Respiration in the Carbon CycleRead next17Photosynthesis in the Carbon CycleRead next18Role of Decomposition in the Carbon CycleRead next19Combustion and Its Impact on the Carbon CycleRead next20Stages of the Nitrogen CycleRead next21Role of Nitrogen-Fixing Bacteria in the Nitrogen CycleRead next22Decomposers in the Nitrogen CycleRead next23Nitrifying and Denitrifying Bacteria in the Nitrogen CycleRead next24Air Pollution: Sulfur Dioxide and Carbon MonoxideRead next25Greenhouse Gases and Their TypesRead next26Human Activities Contributing to Greenhouse GasesRead next27Enhanced Greenhouse Effect and Global WarmingRead next28Biological Consequences of Global WarmingRead next29Water Pollution by SewageRead next30Biological Consequences of EutrophicationRead next31Deforestation and Its Effects on EcosystemsRead next32Leaching and Soil Erosion Due to DeforestationRead next33Deforestation’s Impact on the Carbon CycleRead next34Deforestation’s Impact on Atmospheric GasesRead next35Practical: Investigating Population Size in Different AreasRead next36Practical: Measuring Biodiversity in HabitatsRead next
Using Glasshouses to Increase Crop Yield
1Using Glasshouses to Increase Crop YieldRead next2Effects of Carbon Dioxide on Crop YieldRead next3Effects of Temperature on Crop YieldRead next4Role of Fertilisers in Increasing Crop YieldRead next5Advantages of Pesticides in Pest ControlRead next6Disadvantages of Pesticides in Pest ControlRead next7Biological Control Methods for Crop PlantsRead next8Role of Yeast in Bread ProductionRead next9Investigating Anaerobic Respiration in YeastRead next10Role of Lactobacillus in Yoghurt ProductionRead next11Structure and Function of Industrial FermentersRead next12Conditions for Microbial Growth in FermentersRead next13Methods of Fish Farming for Protein ProductionRead next14Maintaining Water Quality in Fish FarmsRead next15Controlling Predation in Fish FarmsRead next16Preventing Disease in Fish FarmingRead next17Waste Removal in Fish FarmingRead next18Feeding Practices in Fish FarmingRead next19Selective Breeding in Plants for Desired TraitsRead next20Selective Breeding in Animals for Desired TraitsRead next21Using Restriction Enzymes to Cut DNARead next22Using Ligase Enzymes to Join DNARead next23Role of Plasmids as Vectors in Genetic EngineeringRead next24Role of Viruses as Vectors in Genetic EngineeringRead next25Production of Human Insulin Using GM BacteriaRead next26Genetically Modified Plants to Improve Food ProductionRead next27Definition and Examples of Transgenic OrganismsRead next28Process of Micropropagation in PlantsRead next29Commercial Uses of MicropropagationRead next30Stages of Cloning Mammals (Dolly the Sheep Example)Read next31Using Cloned Transgenic Animals to Produce ProteinsRead next
Characteristics of living things
1Characteristics of living thingsRead next2Levels of organisation: organelles to organ systemsRead next3Why multicellular organisms need transport systemsRead next4Sexual vs asexual reproduction and fertilisationRead next5Ecosystems: populations, communities, habitats and ecosystemsRead next6Increasing crop yield: glasshouses, CO₂, temperature and fertilisersRead next7Nutrition, respiration and excretion as life processesRead next8Cells: structures, functions, and plant vs animal cellsRead next9Transport in plants: xylem, phloem and translocationRead next10Pollination: insect vs wind pollinationRead next11Core Practical: Estimating population size using quadratsRead next12Pest control: pesticides vs biological controlRead next13Sensitivity, movement, growth and reproductionRead next14Cell differentiation and stem cells in medicineRead next15Transpiration: water uptake, evaporation and factors affecting rateRead next16Fertilisation in plants: pollen tubes, seeds and fruitsRead next17Biodiversity and why it mattersRead next18Microorganisms in food production (bread and yoghurt)Read next19Eukaryotes: plants and animalsRead next20Biological molecules in food (carbohydrates, lipids, proteins)Read next21Core Practical: Measuring transpiration rateRead next22Core Practical: Conditions needed for seed germinationRead next23Core Practical: Measuring distribution and biodiversity with quadratsRead next24Core Practical: Anaerobic respiration in yeastRead next25Eukaryotes: fungi and protoctistsRead next26Core Practical: Food tests for glucose, starch, protein and fatRead next27Blood: components and what plasma transportsRead next28Germination and early seedling growthRead next29Abiotic and biotic factors affecting distributionRead next30Industrial fermenters and aseptic techniqueRead next31Prokaryotes: bacteria and their key featuresRead next32Enzymes: active sites, catalysis and denaturationRead next33Immunity: phagocytosis, antibodies, vaccination and blood clottingRead next34Asexual reproduction in plants (runners and cuttings)Read next35Trophic levels: producers, consumers and decomposersRead next36Fish farming for food productionRead next37Viruses and why they are not livingRead next38Core Practical: Enzyme activity (temperature and pH)Read next39The heart: structure, function and changing heart rateRead next40Human reproductive systems and gametesRead next41Food chains and food websRead next42Selective breeding in plants and animalsRead next43Pathogens and examples of disease-causing organismsRead next44Movement across membranes: diffusion, osmosis and active transportRead next45Blood vessels and the circulation systemRead next46The menstrual cycle and hormonesRead next47Pyramids of number, biomass and energyRead next48Genetic engineering: tools and processesRead next49Photosynthesis and mineral ions for plant growthRead next50Excretion and osmoregulation: urinary system and kidney functionRead next51Pregnancy: placenta, amniotic fluid and embryo developmentRead next52Energy transfer through ecosystemsRead next53Genetic engineering examples (insulin, GM crops)Read next54Human nutrition, digestion and absorptionRead next55Coordination and response: nervous system, reflexes, the eye and hormonesRead next56Inheritance and evolution: DNA, genes, variation, mutation and natural selectionRead next57Cycles and human impacts (carbon cycle, pollution, climate change)Read next58Cloning: micropropagation and cloning animalsRead next