
Combined Science Revision
Core biology, chemistry and physics for the AQA 8464 Trilogy double award.
AQA GCSE Combined Science: Trilogy (8464) is the double award worth two GCSEs that covers biology, chemistry and physics in one course, and these lessons are written around exactly what the 8464 specification asks for at both Foundation and Higher tier. Its content is a focused subset of the three separate science GCSEs, so you study the core of every science without the extra depth topics that Biology, Chemistry and Physics add on their own. The course is examined in six papers, two per science, and runs from cells, bonding and energy through to inheritance, organic chemistry, forces and waves, including the required practicals examiners can question you on.
Each lesson breaks a topic into clear, exam-ready sections with the definitions, equations, worked calculations and diagrams you need to recall under pressure, and it flags Higher-tier content so you revise the right material. Turn any lesson into a quiz or a flashcard deck in one click to test yourself, and ask the built-in tutor to explain anything from moles and electrolysis to Newton's laws whenever it stops making sense.
Lessons
Cell biology
510 min
LessonCell Structure: Eukaryotes and Prokaryotes
4.1.1.1 Eukaryotes and prokaryotes; 4.1.1.2 Animal and plant cells; 4.1.1.3 Cell specialisation; 4.1.1.4 Cell differentiation
3 months ago
9 min
LessonMicroscopy and Magnification
4.1.1.2 Animal and plant cells (Required practical 1); 4.1.1.5 Microscopy; 4.1.1.1 Eukaryotes and prokaryotes (orders of magnitude and standard form)
3 months ago
9 min
10 min
14 min
LessonDiffusion, Osmosis and Active Transport
4.1.3.1 Diffusion; 4.1.3.2 Osmosis (Required practical 3); 4.1.3.3 Active transport
3 months ago
Organisation
811 min
LessonEnzymes and the Lock-and-Key Model
4.2.1 Principles of organisation; 4.2.2.1 The human digestive system (enzyme action; Required practical 5)
3 months ago
9 min
LessonThe Digestive System and Food Tests
4.2.2.1 The human digestive system (Required practical 4)
3 months ago
10 min
11 min
16 min
8 min
LessonNon-Communicable Diseases and Risk Factors
4.2.2.5 Health issues; 4.2.2.6 The effect of lifestyle on some non-communicable diseases
3 months ago
10 min
14 min
Infection and response
510 min
11 min
LessonViral, Bacterial, Fungal and Protist Diseases
4.3.1.2 Viral diseases; 4.3.1.3 Bacterial diseases; 4.3.1.4 Fungal diseases; 4.3.1.5 Protist diseases
3 months ago
12 min
LessonHuman Defence Systems and the Immune System
4.3.1.6 Human defence systems against pathogens
3 months ago
11 min
12 min
LessonAntibiotics, Painkillers and Drug Development
4.3.1.8 Antibiotics and painkillers; 4.3.1.9 Discovery and development of drugs
3 months ago
Bioenergetics
49 min
LessonPhotosynthesis and Uses of Glucose
4.4.1.1 Photosynthetic reaction; 4.4.1.3 Uses of glucose from photosynthesis
3 months ago
12 min
LessonRate of Photosynthesis and Limiting Factors
4.4.1.2 Rate of photosynthesis (Required practical 6)
3 months ago
9 min
9 min
LessonResponse to Exercise and Metabolism
4.4.2.2 Response to exercise; 4.4.2.3 Metabolism
3 months ago
Homeostasis and response
511 min
LessonThe Nervous System and Reflexes
4.5.1 Homeostasis; 4.5.2.1 The human nervous system (Required practical 7)
3 months ago
11 min
LessonThe Endocrine System and Negative Feedback
4.5.3.1 Human endocrine system; 4.5.3.7 Negative feedback (Higher Tier)
3 months ago
10 min
LessonControl of Blood Glucose and Diabetes
4.5.3.2 Control of blood glucose concentration
3 months ago
8 min
10 min
LessonContraception and Fertility Treatments
4.5.3.5 Contraception; 4.5.3.6 The use of hormones to treat infertility (Higher Tier)
3 months ago
Inheritance, variation and evolution
1011 min
LessonSexual and Asexual Reproduction and Meiosis
4.6.1.1 Sexual and asexual reproduction; 4.6.1.2 Meiosis; 4.6.1.3 Advantages and disadvantages (Biology only)
3 months ago
12 min
LessonDNA, the Genome and Protein Synthesis
4.6.1.4 DNA and the genome; 4.6.1.5 DNA structure (Biology only)
3 months ago
8 min
9 min
LessonInherited Disorders and Sex Determination
4.6.1.7 Inherited disorders; 4.6.1.8 Sex determination
3 months ago
11 min
9 min
11 min
9 min
LessonEvidence for Evolution: Fossils and Extinction
4.6.3.4 Evidence for evolution; 4.6.3.5 Fossils; 4.6.3.6 Extinction
3 months ago
10 min
10 min
Ecology
610 min
LessonEcosystems and Interdependence
4.7.1.1 Communities; 4.7.1.2 Abiotic factors; 4.7.1.3 Biotic factors
3 months ago
9 min
12 min
LessonSampling Techniques: Quadrats and Transects
4.7.2.1 Levels of organisation (Required practical 9)
3 months ago
9 min
12 min
LessonBiodiversity and Human Impact on Ecosystems
4.7.2.4 Impact of environmental change (HT); 4.7.3.1 Biodiversity; 4.7.3.2 Waste management; 4.7.3.3 Land use; 4.7.3.6 Maintaining biodiversity
3 months ago
11 min
Atomic structure and the periodic table
97 min
7 min
7 min
LessonThe Development of the Atomic Model
4.1.1.3 The development of the model of the atom
2 months ago
6 min
LessonAtomic Structure, Isotopes and Relative Atomic Mass
4.1.1.4 Relative electrical charges of subatomic particles; 4.1.1.5 Size and mass of atoms; 4.1.1.6 Relative atomic mass
2 months ago
7 min
8 min
LessonThe Periodic Table and Its Development
4.1.2.1 The periodic table; 4.1.2.2 Development of the periodic table; 4.1.2.3 Metals and non-metals
2 months ago
6 min
6 min
7 min
Bonding, structure, and the properties of matter
78 min
LessonIonic Bonding
4.2.1.1 Chemical bonds; 4.2.1.2 Ionic bonding; 4.2.1.3 Ionic compounds
2 months ago
8 min
6 min
7 min
LessonStates of Matter and State Symbols
4.2.2.1 The three states of matter; 4.2.2.2 State symbols
2 months ago
6 min
LessonProperties of Ionic and Molecular Substances
4.2.2.3 Properties of ionic compounds; 4.2.2.4 Properties of small molecules; 4.2.2.5 Polymers
2 months ago
12 min
LessonGiant Covalent Structures, Metals and Alloys
4.2.2.6 Giant covalent structures; 4.2.2.7 Properties of metals and alloys; 4.2.2.8 Metals as conductors
2 months ago
8 min
LessonAllotropes of Carbon: Diamond, Graphite, Graphene and Fullerenes
4.2.3.1 Diamond; 4.2.3.2 Graphite; 4.2.3.3 Graphene and fullerenes
2 months ago
Quantitative chemistry
56 min
LessonConservation of Mass and Balanced Equations
4.3.1.1 Conservation of mass and balanced chemical equations; 4.3.1.3 Mass changes when a reactant or product is a gas; 4.3.1.4 Chemical measurements
2 months ago
5 min
5 min
5 min
LessonReacting Masses and Limiting Reactants
4.3.2.2 Amounts of substances in equations; 4.3.2.3 Using moles to balance equations; 4.3.2.4 Limiting reactants
2 months ago
5 min
LessonConcentration of Solutions
4.3.2.5 Concentration of solutions; 4.3.4 Using concentrations of solutions in mol/dm³
2 months ago
Chemical changes
67 min
LessonThe Reactivity Series and Displacement
4.4.1.1 Metal oxides; 4.4.1.2 The reactivity series
2 months ago
6 min
LessonExtraction of Metals and Redox
4.4.1.3 Extraction of metals and reduction; 4.4.1.4 Oxidation and reduction in terms of electrons (HT)
2 months ago
7 min
LessonReactions of Acids and Making Salts
4.4.2.1 Reactions of acids with metals; 4.4.2.2 Neutralisation of acids and salt production; 4.4.2.3 Soluble salts
2 months ago
6 min
LessonThe pH Scale, Neutralisation and Strong vs Weak Acids
4.4.2.4 The pH scale and neutralisation; 4.4.2.6 Strong and weak acids (HT)
2 months ago
7 min
LessonElectrolysis of Molten Compounds and Metal Extraction
4.4.3.1 The process of electrolysis; 4.4.3.2 Electrolysis of molten ionic compounds; 4.4.3.3 Using electrolysis to extract metals; 4.4.3.5 Representation of reactions at electrodes as half equations (HT)
2 months ago
7 min
Energy changes
37 min
LessonExothermic and Endothermic Reactions
4.5.1.1 Energy transfer during exothermic and endothermic reactions
2 months ago
6 min
6 min
The rate and extent of chemical change
56 min
7 min
LessonFactors Affecting the Rate of Reaction
4.6.1.2 Factors which affect the rates of chemical reactions
2 months ago
7 min
LessonCollision Theory, Activation Energy and Catalysts
4.6.1.3 Collision theory and activation energy; 4.6.1.4 Catalysts
2 months ago
6 min
LessonReversible Reactions and Equilibrium
4.6.2.1 Reversible reactions; 4.6.2.2 Energy changes and reversible reactions; 4.6.2.3 Equilibrium
2 months ago
6 min
LessonLe Chatelier's Principle and Changing Conditions
4.6.2.4 The effect of changing conditions on equilibrium; 4.6.2.5 The effect of changing concentration; 4.6.2.6 The effect of temperature changes; 4.6.2.7 The effect of pressure changes
2 months ago
Organic chemistry
35 min
6 min
LessonFractional Distillation and Properties of Hydrocarbons
4.7.1.2 Fractional distillation and petrochemicals; 4.7.1.3 Properties of hydrocarbons
2 months ago
6 min
Chemical analysis
37 min
7 min
5 min
LessonTests for Common Gases
4.8.2.1 Hydrogen; 4.8.2.2 Oxygen; 4.8.2.3 Carbon dioxide; 4.8.2.4 Chlorine
2 months ago
Chemistry of the atmosphere
37 min
LessonThe Earth's Early Atmosphere and How It Changed
4.9.1.1 The proportions of different gases in the atmosphere; 4.9.1.2 The Earth's early atmosphere; 4.9.1.3 How oxygen increased; 4.9.1.4 How carbon dioxide decreased
2 months ago
7 min
LessonGreenhouse Gases and Climate Change
4.9.2.1 Greenhouse gases; 4.9.2.2 Human activities which contribute to an increase in greenhouse gases; 4.9.2.3 Global climate change; 4.9.2.4 The carbon footprint and its reduction
2 months ago
6 min
LessonAtmospheric Pollutants from Fuels
4.9.3.1 Atmospheric pollutants from fuels; 4.9.3.2 Properties and effects of atmospheric pollutants
2 months ago
Using resources
39 min
LessonPotable Water and Waste Water Treatment
4.10.1.1 Using the Earth's resources and sustainable development; 4.10.1.2 Potable water; 4.10.1.3 Waste water treatment
2 months ago
6 min
LessonAlternative Methods of Extracting Metals
4.10.1.4 Alternative methods of extracting metals (HT only)
2 months ago
8 min
LessonLife Cycle Assessment and Recycling
4.10.2.1 Life cycle assessment; 4.10.2.2 Ways of reducing the use of resources
2 months ago
Energy
77 min
5 min
5 min
4 min
7 min
7 min
7 min
Electricity
76 min
LessonCircuit Symbols, Charge and Current
4.2.1.1 Standard circuit diagram symbols; 4.2.1.2 Electrical charge and current
2 months ago
5 min
LessonResistance and Ohm's Law
4.2.1.3 Current, resistance and potential difference (including Required practical 3)
2 months ago
7 min
LessonResistors and Circuit Components
4.2.1.4 Resistors and I–V characteristics (including Required practical 4)
2 months ago
6 min
5 min
LessonMains Electricity and Safety
4.2.3.1 Direct and alternating potential difference; 4.2.3.2 Mains electricity
2 months ago
6 min
LessonElectrical Power and Energy Transfers
4.2.4.1 Power; 4.2.4.2 Energy transfers in everyday appliances
2 months ago
6 min
Particle model of matter
46 min
5 min
6 min
6 min
Atomic structure
67 min
LessonAtomic Structure and Isotopes
4.4.1.1 The structure of an atom; 4.4.1.2 Mass number, atomic number and isotopes
2 months ago
6 min
LessonThe Development of the Atomic Model
4.4.1.3 The development of the model of the atom
2 months ago
6 min
LessonRadioactive Decay and Nuclear Radiation
4.4.2.1 Radioactive decay and nuclear radiation
2 months ago
5 min
6 min
LessonHalf-life and Radioactive Decay
4.4.2.3 Half-lives and the random nature of radioactive decay
2 months ago
9 min
LessonRadioactive Contamination, Hazards and Uses
4.4.2.4 Radioactive contamination; 4.4.3 Hazards and uses of radioactive emissions and of background radiation
2 months ago
Forces
107 min
6 min
7 min
5 min
7 min
5 min
7 min
6 min
8 min
6 min
Waves
56 min
7 min
LessonWave Properties and the Wave Equation
4.6.1.2 Properties of waves (including Required practical 8)
2 months ago
6 min
8 min
LessonProperties and Hazards of Electromagnetic Waves
4.6.2.2 Properties of electromagnetic waves 1; 4.6.2.3 Properties of electromagnetic waves 2
2 months ago
6 min
LessonUses of Electromagnetic Waves
4.6.2.4 Uses and applications of electromagnetic waves
2 months ago
Magnetism and electromagnetism
36 min
6 min
LessonElectromagnetism and the Motor Effect
4.7.2.1 Electromagnetism; 4.7.2.2 Fleming's left-hand rule (HT)
2 months ago
5 min
LessonElectric Motors and Loudspeakers
4.7.2.3 Electric motors (HT); 4.7.2.4 Loudspeakers (Separate Physics, HT)
2 months ago
Frequently asked questions
It is assessed by six written papers, two each in biology, chemistry and physics. Each paper is 1 hour 15 minutes, worth 70 marks and 16.7% of the GCSE, and there is no coursework, though questions can test the required practicals.
Two. Combined Science: Trilogy is a double award, so it counts as two of your GCSEs and gives two grades reported together, from 9-9 at the top down to 1-1.
Combined Science covers the same core topics as separate Biology, Chemistry and Physics but leaves out the extra depth content, and it is worth two GCSEs rather than three. It is the route most students take unless they are entered for the three separate sciences.
Foundation tier targets the lower grades and Higher tier targets the higher grades, and you sit the same tier across all six papers. Higher tier includes extra content such as moles calculations and Le Chatelier's principle, so revise to the tier you are entered for.
There are 21 required practicals across the course, spread over biology, chemistry and physics. Exam questions often test the method, variables and reasoning behind a practical rather than just the result.
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