GCSE Combined Science Topics: AQA, Edexcel & OCR

Combined Science covers three subjects - Biology, Chemistry and Physics - squeezed into two GCSEs. 

Revise the wrong board's topic list and you'll spend hours on content that never shows up in your exam, while gaps you didn't know you had go untouched. 

This guide lists every GCSE Combined Science topic on the AQA, Edexcel and OCR GCSE Combined Science specifications, broken down by subject and by paper. This means you can build a revision plan around what your exam board actually tests.

Key Takeaways

• Combined Science is worth two GCSEs and covers Biology, Chemistry and Physics.

• AQA, Edexcel and OCR all organise their content differently, so check which board you're on before you start revising.

• Each board splits its content into six exam papers, two per subject.

• This guide covers: AQA GCSE Combined Science Trilogy (8464), Edexcel GCSE (9-1) Combined Science (1SC0), and OCR GCSE (9-1) Combined Science A / Gateway Science (J250).

Why Your Exam Board Matters

Combined Science isn't a fixed syllabus. Each exam board writes its own specification. Content, wording and paper structure all vary between them.

If you're not sure which board you're studying, check with your teacher or look at the code on your last set of past papers.

Unlike some GCSEs, Combined Science topic content doesn't change much between Foundation and Higher tier. The tier mostly affects which grades you can achieve and how questions are pitched. We'll flag any exceptions below.

AQA GCSE Combined Science: Trilogy (8464)

AQA's Combined Science: Trilogy specification (opens in a new tab) is split into Biology, Chemistry and Physics, with:

• 7 topics in Biology

• 10 topics in Chemistry 

• 7 topics in Physics

Biology Topics

1. Cell biology

2. Organisation

3. Infection and response

4. Bioenergetics

5. Homeostasis and response

6. Inheritance, variation and evolution

7. Ecology

1: Cell biology

This topic covers the structure and function of eukaryotic and prokaryotic cells, with a focus on animal and plant cells and their organelles. You’ll learn about cell specialisation and differentiation, which explain how cells develop specific functions for the organism.

The cell cycle and mitosis are also explored, showing how cells divide and replicate and key processes like diffusion, osmosis, and active transport, which help substances move in and out of cells. 

2: Organisation

This topic explains how living organisms are organised into systems. You’ll study the structure and function of the digestive system, with an emphasis on enzymes and metabolism.

It also explores the lungs, heart, and blood vessels in the circulatory system and how they work together to deliver oxygen and nutrients. The impact of coronary heart disease (CHD) and lifestyle factors on health is included.

Finally, you’ll study plant tissues, transpiration, and translocation to understand how plants transport water and nutrients.

3: Infection and response

This topic examines communicable diseases caused by viruses, bacteria, fungi, and protists. 

You’ll explore how pathogens spread and how the body’s immune system, particularly white blood cells, defends against them. It also introduces vaccination and discusses the role of antibiotics and painkillers in preventing and treating infections.

4: Bioenergetics

This topic introduces photosynthesis, how plants convert light energy into chemical energy. You’ll study the reaction itself, key limiting factors (light intensity, temperature, CO2 concentration), and the role of chlorophyll. 

A required practical helps you investigate how these factors affect the rate. You’ll also explore the various uses of glucose, such as for respiration, or to produce starch, lipids, cellulose, and amino acids.

5: Homeostasis and response

This topic explains homeostasis, how the body maintains stable internal conditions like temperature and blood glucose. You’ll also study the reflex arc as an example of an automatic response, supported by a reaction time practical. 

The topic explores the endocrine system, focusing on insulin and glucagon in regulating blood glucose. You’ll also learn about hormones in human reproduction, including how they regulate the menstrual cycle, contraception, and fertility treatments like IVF. 

6: Inheritance, Variation & Evolution

This topic compares sexual and asexual reproduction, explaining how meiosis leads to the formation of gametes for genetic diversity. 

You’ll study DNA, genetic inheritance, and Mendelian principles, along with inherited disorders caused by mutations. The topic also covers selective breeding, genetic engineering, and cloning, helping you understand how humans influence inheritance.

The topic continues with variation, evolution, and the process of natural selection. The evidence for evolution, including fossils, extinction, and the role of resistant bacteria, is explored, alongside classification systems for grouping organisms.

7: Ecology

This section focuses on how organisms interact with their environment, exploring abiotic factors (e.g., light, temperature) and biotic factors (e.g., plants, animals). You’ll learn about adaptations that help organisms survive in specific environments and the importance of biodiversity.

Levels of organisation, from individual organisms to ecosystems, with a required practical on ecosystems are covered. The section also addresses human impacts on ecosystems, including deforestation and global warming, and strategies for maintaining biodiversity through conservation efforts.

Chemistry Topics

1. Atomic structure and the periodic table

2. Bonding, structure and the properties of matter

3. Quantitative chemistry

4. Chemical changes

5. Energy changes

6. The rate and extent of chemical change

7. Organic chemistry

8. Chemical analysis

9. Chemistry of the atmosphere

10. Using resources

1: Atomic structure and the Periodic Table

This topic explains how the Periodic Table is organised to help chemists understand the properties of elements. 

You’ll study atomic structure, including the nucleus with protons and neutrons, and electrons arranged in energy levels. This model helps explain element behaviour and properties.

You’ll also explore how the Periodic Table developed from Mendeleev’s early model to the modern version based on atomic number. 

Finally, the topic examines the properties of metals, non-metals, and important groups like Noble Gases, Alkali Metals, and Halogens.

2: Bonding, Structure, and the properties of matter

This topic introduces chemical bonding. You’ll compare ionic bonding (electron transfer), covalent bonding (electron sharing), and metallic bonding (delocalised electrons). These bonding types explain the physical properties of different substances.

You’ll also study particle theory to understand how solids, liquids, and gases behave. This helps explain the structure and properties of ionic compounds, small molecules, polymers, and giant covalent structures like diamond and graphite. 

The topic also explores materials such as graphene, fullerenes, and alloys.

3: Quantitative chemistry

This topic explains the principle of conservation of mass, that mass is conserved in chemical reactions. You’ll practise balancing equations and calculating relative formula mass, key skills for chemical calculations.  

The concept of the mole is introduced to link the mass of a substance to the number of particles, with students using moles to balance equations and calculate the amounts of substances. 

The topic also covers uncertainty, limiting reactants and the concentration of solutions, helping you understand how chemical quantities are related.

4: Chemical changes

This topic covers metal oxides and the reactivity series, ranking metals based on their reactivity. You’ll learn how reduction is used to extract metals from their ores and how oxidation and reduction involve the transfer of electrons.

You will also study metal and acid reactions as redox reactions, focusing on neutralisation to produce salts. 

The section also includes soluble salts and a required practical on preparing them. pH and the differences between strong and weak acids are also discussed, alongside electrolysis, used to extract metals and perform chemical reactions in molten ionic compounds and aqueous solutions.

5: Energy changes

This topic looks at energy changes in chemical reactions. 

You’ll explore how breaking and forming bonds absorbs or releases energy. Reaction profiles help visualise these changes and distinguish between exothermic and endothermic reactions.

6: Rate and extent of chemical change

This topic covers how reaction rates can be calculated using moles and how factors like temperature, concentration, and surface area affect the rate. A required practical investigates the effect of concentration on reaction rates.

You’ll study collision theory, which explains how reactions happen when particles collide with enough energy. Catalysts are also introduced for their role in lowering activation energy.

Finally, the topic explores reversible reactions and equilibrium, showing how changes in conditions like concentration, temperature, and pressure influence the balance of reactions.

7: Organic chemistry

This topic covers crude oil, a mixture of hydrocarbons, and how fractional distillation is used to separate it into useful products like petrol and diesel. Petrochemicals are discussed, as well as the properties of hydrocarbons.

You’ll study the process of cracking, which breaks down large hydrocarbons into smaller molecules like alkenes. These molecules are more reactive than alkanes and have various industrial applications.

8: Chemical analysis

This topic explains the difference between pure substances and formulations. You’ll use chromatography, including a required practical, to separate mixtures and identify components. 

It also covers tests for gases like hydrogen, oxygen, carbon dioxide, and chlorine, using characteristic reactions.

9: Chemistry of the atmosphere

This topic explores the Earth’s early atmosphere, how volcanic activity formed it, how oxygen levels increased through photosynthesis, and how carbon dioxide decreased over time. 

You’ll then learn about greenhouse gases (like CO2 and methane), their role in global warming, and the uncertainty involved in climate modelling.

The topic also covers the carbon footprint and methods to reduce it, such as using renewable energy and energy efficiency measures. 

You’ll learn about atmospheric pollutants from fuels, including carbon monoxide, sulfur dioxide, nitrogen oxides, particulates, and unburned hydrocarbons, and their environmental and health effects such as acid rain, global dimming, and respiratory issues.

10: Using Resources

This topic explains how potable water is produced, including a required practical on water purification. You’ll also learn about wastewater treatment and methods like bioleaching to extract metals sustainably.

Life cycle assessments (LCAs) are introduced to evaluate the environmental impact of products like glass or paper. The topic concludes with strategies for reducing resource use, such as recycling and switching to renewable resources.

Physics Topics

1. Energy

2. Electricity

3. Particle model of matter

4. Atomic structure

5. Forces

6. Waves

7. Magnetism and electromagnetism

1: Energy 

This topic introduces different energy stores and how energy is transferred between them in systems. You’ll study conservation of energy and calculate how energy is transferred, how power and efficiency are measured, and how energy can be lost as heat. 

You’ll apply these ideas through practicals and by comparing renewable and non-renewable energy resources in real-life situations.

2: Electricity

This topic introduces the fundamentals of electricity, covering electric current, voltage, and resistance. You’ll explore how these key electrical properties are measured and understood in simple circuits. 

Through practical experiments, students will investigate Ohm’s Law and learn how electrical components such as resistors and batteries affect the flow of current in a circuit.

The topic also covers circuit diagrams and the differences between series and parallel circuits, helping you visualise how electrical systems are connected. 

You’ll study the characteristics of different components such as diodes, thermistors, and LDRs, and how current flows through various materials and components, which is essential for understanding the behaviour of electrical circuits in both practical and theoretical contexts.

3: Particle model of matter

This topic explains the behaviour of particles in solids, liquids, and gases. You’ll learn how particles move and interact differently in each state of matter, affecting properties such as density and compressibility. 

The particle model helps explain changes in state (e.g., melting, boiling), the difference between latent heat and specific heat capacity, and why substances behave differently under varying conditions of temperature and pressure. 

This understanding forms the basis for studying gas laws, where the relationships between pressure, volume, and temperature of gases are explained using particle theory.

4: Atomic structure

This topic covers atomic structure, introducing the nucleus, made of protons and neutrons, and electrons arranged in energy levels. You’ll explore how the atomic model developed over time, including ideas like the electron cloud and quantum theory.

You’ll learn about isotopes and radioactive decay, where unstable nuclei release radiation. The topic introduces alpha, beta, and gamma radiation, and how they are used in medicine, industry, and environmental applications.

You’ll also study nuclear equations, how alpha and beta decay affect atomic structure, and how half-life describes the decay of radioactive substances. Finally, the topic compares the hazards of contamination and irradiation, and how radiation risks are managed.

5: Forces

This topic focuses on understanding speed, velocity, acceleration, and force. 

You’ll learn how these quantities relate to one another and how they can be measured. Newton’s Second Law of motion is covered to explain the relationship between force, mass, and acceleration, helping students understand how objects move in response to external forces.

Practical activities, such as using spring scales to measure force, will enable you to connect theoretical concepts with real-world experiences. 

The topic also explores gravitational force, friction, and air resistance, highlighting how these forces affect the motion of objects on Earth and in space.

6: Waves

This topic covers the fundamental properties of waves, such as frequency, wavelength, and amplitude. Students learn how transverse waves (like light) and longitudinal waves (like sound) behave differently.

You’ll have the opportunity to investigate how sound waves and light waves travel through different mediums and how these waves interact with materials. 

Practical experiments allow students to observe wave reflection and refraction, which are key to understanding how waves are used in technology like communication and imaging.

7: Magnetism and electromagnetism

This topic introduces magnetic fields and how they interact with electric currents to create electromagnets. You’ll learn about the role of electromagnetism in devices like electric motors and explore how magnetic fields influence the motion of charged particles.

Practical activities, including building simple motors, help students understand how magnetic fields and electric currents interact, a principle used in many everyday technologies that involve movement and control systems.

AQA Paper Structure

Each paper is a 1 hour 15 minute written exam worth 70 marks (16.7% of the GCSE), sat at Foundation or Higher tier, with multiple choice, structured, short answer and open response questions. 

Edexcel GCSE (9-1) Combined Science (1SC0)

Edexcel's specification (opens in a new tab) covers:

• 9 Biology topics

• 7 Chemistry topics 

• 13 Physics topics

Biology Topics

1. Key concepts in biology

2. Cells and control

3. Genetics

4. Natural selection and genetic modification

5. Health, disease and the development of medicines

6. Plant structures and their functions

7. Animal coordination, control and homeostasis

8. Exchange and transport in animals

9. Ecosystems and material cycles

1: Key Concepts in Biology

This topic introduces core biological ideas. You’ll learn about the structure and function of animal, plant, and bacterial cells, including how specialised cells are adapted to their roles. The topic also covers the use of light and electron microscopes and includes practical work on preparing and observing slides.

You’ll explore how enzymes break down and build molecules like carbohydrates, proteins, and lipids, and how factors such as temperature and pH affect their activity. The topic ends with how substances move into and out of cells through diffusion, osmosis, and active transport, supported by calculations and practical investigation.

2: Cells and Control

This topic explains how cells divide, grow, and develop. You'll study mitosis as part of the cell cycle and how it supports growth, repair, and asexual reproduction. Cancer is introduced as a disease caused by uncontrolled cell division. Growth in animals and plants is compared, focusing on differences in cell division, elongation, and the role of stem cells. You’ll also evaluate how stem cells are used in medicine and the potential risks.

The topic ends with the structure and function of the nervous system. You’ll learn how neurones transmit impulses and how reflex arcs help the body respond quickly. Practical investigations include measuring reaction time and nerve impulse speed.

3: Genetics

This topic explains how genetic information is inherited. You’ll learn about chromosomes, genes, and alleles, and how dominant and recessive traits are passed from parents to offspring. Punnett squares are used to predict inheritance outcomes, including monohybrid crosses and sex determination.

The topic also explores variation within species, both from genetic and environmental factors. You’ll consider inherited disorders like cystic fibrosis, as well as the ethical issues raised by genetic screening.

4: Natural Selection and Genetic Modification

This topic introduces the theory of evolution by natural selection. You’ll learn how organisms adapt to their environments over time, supported by evidence from fossils and antibiotic-resistant bacteria.

It also explores how humans influence genetics through selective breeding, genetic engineering, and tissue culture. You’ll learn how genetic modification is used in farming, medicine, and industry, and consider some of the benefits and risks involved.

5: Health, Disease, and the Development of Medicines

This topic looks at both communicable and non-communicable diseases. You’ll learn about infections caused by viruses, bacteria, fungi, and protists, and how diseases can be prevented through hygiene, isolation, and vaccination. The role of the immune system is introduced, including how white blood cells defend the body.

You’ll also study how medicines are developed and tested. This includes the use of antibiotics to treat bacterial infections and the issue of antibiotic resistance. Non-communicable conditions such as cardiovascular disease are explored, along with lifestyle factors that affect health.

6: Plant Structures and Their Functions

This topic focuses on the structure and function of plant organs including roots, stems, leaves, and flowers. You’ll learn how these organs support growth and reproduction, and how substances like water and minerals are transported through xylem and phloem. 

The role of stomata in gas exchange and the process of transpiration are also covered, including a required practical on measuring transpiration rates.

You’ll explore the process of  photosynthesis, including its word and symbol equations. Factors that affect the rate of photosynthesis such as light intensity and temperature, are investigated using practical methods and data analysis.

7: Animal Coordination, Control, and Homeostasis

This topic explains how the body controls internal conditions through the nervous system and the endocrine system. You’ll study the roles of adrenaline and thyroxine in regulating metabolism and stress responses. 

The nervous system is introduced as a fast-response system involving receptors, neurones, and effectors.

You’ll explore how homeostasis keeps conditions like temperature and blood glucose levels within a narrow range. The actions of insulin and glucagon in blood sugar regulation are covered, along with how negative feedback helps maintain stability.

8: Exchange and Transport in Animals

This topic explores the structure and function of the circulatory system, including the heart, blood vessels, and blood. 

You’ll learn how the double circulatory system transports oxygen and nutrients around the body and removes waste products. The roles of red blood cells, plasma, white blood cells, and platelets are also covered.

You’ll also study how gases are exchanged in the lungs, particularly at the alveoli. The importance of capillaries in allowing substances to move between blood and tissues is explained, helping you understand how materials are transported and exchanged in living organisms.

9: Ecosystems and Material Cycles

This topic examines how ecosystems function and how energy is transferred between organisms. 

You’ll study food chains and food webs, the roles of producers, consumers, and decomposers, and how biotic and abiotic factors affect population sizes. Practical work includes methods for estimating population changes in habitats.

You’ll also explore how materials are recycled through the carbon, water, and nitrogen cycles. The role of microorganisms in decay is covered, along with a required practical on the factors that affect decomposition. 

Finally, the topic looks at human impacts on biodiversity, including pollution, habitat destruction, and conservation strategies.

Chemistry Topics

1. Key concepts in chemistry

2. States of matter and mixtures

3. Chemical changes

4. Extracting metals and equilibria

5. Groups in the periodic table

6. Rates of reaction and energy changes

7. Fuels and Earth science

1: Key Concepts in Chemistry

This topic introduces the structure of atoms, including protons, neutrons, and electrons, and how elements are arranged in the Periodic Table. You'll learn how to form ions and distinguish between metals and non-metals. The topic also covers how to represent chemical reactions using word equations, symbol equations, and state symbols.

You’ll explore three types of chemical bonding: ionic and covalent. For each type, you’ll study how bonding affects structure and physical properties. Examples include ionic lattices, simple covalent molecules, giant covalent structures like diamond and graphite, polymers, and metallic substances.

The topic also introduces key chemical calculations. These include relative formula mass, the mole, reacting masses, and concentration calculations for solutions. You’ll apply these skills to interpret chemical data and solve problems involving balanced equations and conservation of mass.

2: States of Matter and Mixtures

This topic explores the physical properties of solids, liquids, and gases using the particle model. You’ll study how temperature and pressure affect particle arrangement and energy, leading to changes in state such as melting, boiling, and condensation. The differences between pure substances and mixtures are introduced.

You’ll also learn how to separate mixtures using techniques like filtration, crystallisation, distillation, and chromatography. These methods are linked to practical applications, including a required practical on chromatography.

3: Chemical Changes

This topic explores different types of chemical reactions, including acid-base reactions and redox reactions. You’ll learn how to use the pH scale, investigate neutralisation reactions through practical work, and understand the difference between strong and weak acids. The preparation of soluble salts is also covered.

You’ll study the reactivity series of metals and how it is used to predict reactions. Methods of metal extraction, including displacement and electrolysis, are explained, along with the factors that affect their practical use.

4: Extracting Metals and Equilibria

This topic explains how metals are extracted from their ores based on their position in the reactivity series. You’ll study how reduction with carbon is used for less reactive metals, while more reactive metals require electrolysis. These methods are evaluated based on practical and economic considerations.

You’ll also learn about dynamic equilibrium and how it applies to reversible reactions. The effects of changing temperature, pressure, and concentration are explored using examples from industrial processes such as the Haber process.

5: Groups in the Periodic Table

This topic explores the properties and trends in three key groups: Group 1 (alkali metals), Group 7 (halogens), and Group 0 (noble gases). 

You’ll study how reactivity, melting and boiling points, and atomic structure change as you move down each group. Group 1 metals are examined for their reactions with water and oxygen, while Group 7 elements are explored through displacement reactions.

You’ll also learn why Group 0 elements are unreactive and how their stable electron configurations relate to their chemical behaviour. The uses of elements from these groups in everyday life, such as noble gases in lighting and halogens in disinfectants, are also discussed.

6: Rates of Reaction and Energy Changes

This topic explores the factors that affect how quickly chemical reactions take place. You’ll learn how temperature, concentration, surface area, and catalysts influence the rate of reaction. 

Collision theory is introduced to explain these effects, and a required practical investigates how changing conditions affect reaction rate.

You’ll also study energy changes in chemical reactions. The differences between exothermic and endothermic reactions are explained using examples and reaction profiles. Activation energy and the use of catalysts to lower it are also covered.

7: Fuels and Earth Science

This topic explores how fuels are extracted from crude oil and used to generate energy. You’ll learn how fractional distillation separates crude oil into useful products and how complete and incomplete combustion produce different gases. 

Pollutants such as carbon dioxide, carbon monoxide, sulfur dioxide, and particulates are studied, along with their effects on health and the environment.

You’ll also examine how the Earth’s atmosphere has changed over time, from its early composition to the modern mix of gases. The greenhouse effect and its link to climate change are covered, along with the evidence for human impact. 

Finally, the topic introduces renewable energy sources and the importance of sustainable development.

Physics Topics

1. Key concepts in physics

2. Motion and forces

3. Conservation of energy

4. Waves

5. Light and the electromagnetic spectrum

6. Radioactivity

7. Energy – forces doing work

8. Forces and their effects

9. Electricity and circuits

10. Magnetism and the motor effect

11. Electromagnetic induction

12. Particle model

13. Forces and matter

1: Key Concepts in Physics

This topic introduces the core skills and language used throughout the physics course. You’ll learn the difference between scalar and vector quantities, and how to describe motion using distance, speed, velocity, and acceleration. 

Key equations are introduced, and you’ll practise rearranging and using them in calculations.

The topic also covers SI units, standard form, significant figures, and unit conversions. These tools help you work with data accurately and apply physics principles to real-world problems

2: Motion and Forces

This topic explains how objects move and interact. You’ll learn how to calculate speed, velocity, and acceleration, and how to interpret motion using distance–time graphs. 

Newton’s laws of motion are introduced to explain how forces affect movement, including the relationship between force, mass, and acceleration.

You’ll also explore the effects of friction, air resistance, and resultant forces. The topic includes stopping distances, thinking and braking times, and factors that affect road safety. 

Equations and practical investigations are used to help you understand and predict how objects behave in different situations.

3: Conservation of Energy

This topic explains the principle of energy conservation; energy cannot be created or destroyed, only transferred between stores. 

You’ll learn about different energy stores such as kinetic, gravitational potential, elastic, and thermal, and how energy is transferred in mechanical, electrical, and heating processes.

The topic also explores energy dissipation and how energy becomes less useful when transferred. You’ll use equations to calculate energy changes and efficiency, helping you understand how energy is used in real-world devices and systems.

4: Waves

This topic explores the properties of waves, including frequency, wavelength, amplitude, and wave speed. 

You’ll learn the difference between transverse and longitudinal waves, and how to use the wave equation to calculate speed, frequency, or wavelength. Required practicals help you investigate how waves travel through different materials.

You’ll also study how waves behave when they meet a surface, including reflection, refraction, transmission, and absorption. The topic explains how waves are used in technologies such as sound, ultrasound, and light, with examples from everyday applications.

5: Light and the Electromagnetic Spectrum

This topic explores how light behaves when it travels through different materials. You’ll study the laws of reflection and refraction, and how the direction of light changes depending on the properties of the medium.

The topic also introduces the electromagnetic spectrum, including the order of waves from radio to gamma rays. You’ll learn how each type of wave is used in technologies such as communication, medicine, and security, and how their frequency and wavelength affect their behaviour. 

The risks of exposure to certain types of radiation, such as ultraviolet and X-rays, are also discussed.

6: Radioactivity

This topic explores the structure of the atom and how unstable nuclei emit radiation to become more stable. You’ll learn about alpha, beta, and gamma radiation, including their properties, how they affect atoms, and the materials needed to shield against them. The differences between contamination and irradiation are also covered.

You’ll also study the concept of half-life and how it is used to measure the rate of radioactive decay. The uses of radiation in medicine, industry, and research are explained, along with how the risks of exposure are managed.

7: Energy – Forces Doing Work

This topic explores how applying a force to an object transfers energy. You’ll learn how to calculate work done using the equation work = force × distance, and how energy is transferred in mechanical systems.

You’ll also study elastic potential energy and how it relates to the stretching of springs. A required practical helps you investigate the relationship between force, extension, and energy stored, using the spring constant.

8: Forces and Their Effects

This topic explores how different forces, including gravitational, frictional, and electrostatic forces, affect the motion and shape of objects. You’ll learn to distinguish between contact and non-contact forces, and how to calculate resultant forces using vector diagrams. The topic also includes pressure in fluids and the stretching and compression of objects.

You’ll study how forces cause changes in momentum, and how this links to Newton’s Third Law. Conservation of momentum in collisions is covered, along with practical applications in safety and transport.

9: Electricity and Circuits

This topic covers the key principles of electric circuits, including current, potential difference (voltage), and resistance. You’ll learn how they are related using Ohm’s Law and how to apply equations to calculate power, energy transfer, and current in different parts of a circuit. Required practicals help you investigate resistance in wires and components.

You’ll also study the differences between series and parallel circuits and how components behave in each. The topic includes the function of everyday electrical devices, such as fuses and heating elements, and how circuits are used safely in homes and appliances.

10: Magnetism and the Motor Effect

This topic focuses on magnetic fields and how they are produced by magnets and electric currents. You’ll study how to visualise field patterns, investigate how field strength can be increased in electromagnets, and understand the factors that affect magnetic force.

The motor effect is also introduced, showing how a wire carrying a current in a magnetic field experiences a force. You’ll use Fleming’s Left-Hand Rule to predict the direction of movement, and explore how this principle is used in electric motors.

11: Electromagnetic Induction

This topic explains how a changing magnetic field can induce a potential difference in a conductor. You’ll learn how moving a wire through a magnetic field, or changing the magnetic field around a coil, can generate electricity. The size and direction of the induced current depend on the speed and direction of movement and the magnetic field.

You’ll also explore how electromagnetic induction is used in generators, transformers, and the National Grid. Transformers change the voltage of alternating current, making electricity transmission more efficient over long distances.

12: Particle Model

This topic explores how the particle model explains the behaviour of solids, liquids, and gases. You’ll learn how temperature and pressure affect the motion and spacing of particles, and how changes in internal energy relate to heating and cooling. The concept of density is introduced, along with a required practical to measure the density of regular and irregular objects.

You’ll also study how energy is transferred when materials change temperature or state. This includes specific heat capacity and specific latent heat, helping to explain the physical properties of substances during heating, cooling, and state changes.

13: Forces and Matter

This topic explores how materials change shape when forces are applied. You’ll study the difference between elastic and plastic deformation, and how the force–extension relationship is described by Hooke’s Law up to the limit of proportionality.

You’ll also investigate how materials respond to stretching using a required practical. These ideas help explain how stress, strain, and internal structure influence how different materials behave under force.

Edexcel Paper Structure

Each paper is a 1 hour 10 minute written exam worth 60 marks (16.7% of the GCSE), with multiple choice, short answer, calculation and extended open-response questions. 

OCR GCSE (9–1) Combined Science A: Gateway Science (J250)

OCR splits its content into six topics per subject, plus a shared practical skills topic (CS7) that runs across all three sciences.

Biology Topics

• B1: Cell level systems

• B2: Scaling up

• B3: Organism level systems

• B4: Community level systems

• B5: Genes, inheritance and selection

• B6: Global challenges

B1: Cell Level Systems

In this topic, you’ll explore the structure of both animal and plant cells, as well as prokaryotic cells. You’ll learn how microscopes, including electron microscopes, help us understand cells in more detail. 

You’ll learn how DNA is used to make proteins, and how enzymes act as biological catalysts in processes such as respiration. 

The topic compares aerobic and anaerobic respiration and looks at how organisms use carbohydrates, proteins, and lipids. 

Finally, you'll study how plants use photosynthesis to make food and how light, temperature, and carbon dioxide levels affect its rate.

B2: Scaling Up

This topic explains how diffusion, osmosis, and active transport make that possible. You’ll also explore how cells divide by mitosis and how the stages of the cell cycle lead to growth and development in multicellular organisms.

You’ll learn how cells become specialised for different roles, and how stem cells help with growth and repair. 

You’ll also examine how surface area to volume ratio affects diffusion and why systems like the circulatory system in humans or vascular tissue in plants are needed. This includes the structure and function of the heart, blood, root hair cells, xylem, and phloem. 

You’ll also learn about processes like transpiration and translocation, and how environmental conditions affect the rate of water uptake in plants.

B3: Organism Level Systems

In this topic, you’ll study how the nervous system uses sensory, relay, and motor neurones to carry messages and control responses. 

You’ll learn how reflex arcs work and how the brain coordinates information from the senses. You’ll also explore the endocrine system and how hormones like adrenaline, thyroxine, oestrogen, and testosterone regulate processes such as the menstrual cycle and reproduction.

You’ll explore the idea of homeostasis, which means keeping internal conditions steady and you’ll learn how insulin and glucagon work together to regulate blood sugar, and how this links to diabetes. 

B4: Community Level Systems

In this topic, you’ll learn how different levels of organisation, from individuals to whole ecosystems, fit together. 

You’ll study how abiotic and biotic factors affect communities, and how organisms compete for resources. You’ll also explore how organisms depend on each other through relationships like predation, mutualism, and parasitism.

You’ll learn how materials like carbon, nitrogen, and water cycle between the living and non-living parts of ecosystems. Microorganisms play a key role in these cycles by breaking down waste and dead matter. 

The topic also looks at feeding relationships, how food webs show the flow of biomass, and why simple food webs help us understand interdependence more clearly.

B5: Genes, Inheritance, and Selection

In this topic, you’ll explore key ideas such as chromosomes, genes, alleles, and DNA. You’ll learn how dominant and recessive alleles affect the traits we see, and how Punnett squares can predict outcomes of genetic crosses. 

The topic also introduces variation, mutation, and the role of meiosis in forming gametes and maintaining genetic diversity. You’ll compare single gene inheritance with traits controlled by multiple genes, and see how sex is genetically determined.

You’ll also explore how evolution happens over time through natural selection. You’ll learn how random mutations and environmental pressures lead to advantageous traits becoming more common in a population. 

The topic includes evidence for evolution, such as fossils and antibiotic resistance in bacteria, and explains how changes in inherited traits can lead to new species forming.

B6: Global Challenges

This topic explores how biology is used to tackle global problems. You’ll learn how scientists monitor ecosystems, measure biodiversity, and evaluate how human actions affect the environment. 

You’ll also explore methods used to investigate the distribution and abundance of organisms, including ecological sampling techniques.

You’ll study how genes are modified to create crops with useful traits, and the benefits and risks of using gene technology in farming and medicine. 

The topic also covers how diseases spread, how the body defends itself, and how vaccines and new medicines help us stay healthy in a changing world.

Chemistry Topics

• C1: Particles

• C2: Elements, compounds and mixtures

• C3: Chemical reactions

• C4: Predicting and identifying reactions and products

• C5: Monitoring and controlling chemical reactions

• C6: Global challenges

C1: Particles

This topic begins with the particle model, which describes how solids, liquids, and gases behave. You’ll learn how particle arrangement and movement explain changes of state, and how to distinguish between physical and chemical changes.

You’ll then move on to atomic structure and how scientific models of the atom have changed over time. You’ll study how atoms are made of protons, neutrons, and electrons, and how their arrangement explains atomic properties. 

The topic includes calculating numbers of subatomic particles, understanding isotopes, and recognising the size scale of atoms and molecules. You’ll also learn how to use atomic and mass numbers to represent atoms and ions using standard notation.

C2: Elements, Compounds, and Mixtures

This topic explores the differences between elements, compounds, and mixtures, and explains how to identify pure substances using melting points. You’ll learn about common mixtures like alloys and formulations, and study methods for separating mixtures, including filtration, crystallisation, distillation, and chromatography. 

The topic also covers interpreting chromatograms and calculating Rf values, as well as how to determine empirical and relative formulae from data.

You’ll then move on to how atoms bond to form different substances. You’ll study ionic, covalent, and metallic bonding, and use models such as dot and cross diagrams to show how atoms form compounds. 

The topic explains how bonding and structure affect the properties of substances, including the bulk properties of metals, polymers, and giant covalent structures. You’ll also learn how carbon can form many different materials like diamond, graphite, fullerenes, and graphene, and how their properties link to their bonding and structure.

C3: Chemical Reactions

This topic introduces different types of chemical reactions and how to represent them using formulae, equations, and state symbols. 

You’ll learn about the conservation of mass, how to calculate reacting masses and moles, and how to use the Avogadro constant. 

The topic also covers combustion, oxidation, and neutralisation reactions, including reactions of acids with metals, carbonates, and alkalis. You’ll explore pH, indicators, and how acids differ in strength and concentration.

You’ll study how energy is transferred during chemical reactions and how to interpret reaction profiles. This includes the difference between exothermic and endothermic reactions, and how bond breaking and making relate to energy changes. 

The topic ends with electrolysis, where you’ll learn how electricity breaks down ionic compounds, how to predict the products formed at electrodes, and how to write half equations for the reactions that take place.

C4: Predicting and Identifying Reactions and Products

This topic focuses on how the periodic table helps us predict the properties and reactions of elements. You’ll learn about the trends in physical and chemical properties across Groups 1, 7, and 0, and how these relate to the number of electrons in the outer shell. 

The topic also explains how electron structure affects how easily atoms gain or lose electrons, and how this links to their reactivity.

You’ll explore displacement reactions and how to use experimental results to deduce the order of reactivity of metals. The topic also covers how metals react with water and acids, and how to predict the products of these reactions. 

You’ll practise balancing equations for chemical reactions and interpreting results to make predictions about how different elements will behave.

C5: Monitoring and Controlling Chemical Reactions

This topic explores how the rate of chemical reactions can be controlled and measured. You’ll learn how factors like temperature, concentration, surface area, and catalysts affect reaction rate, and how to explain these effects using collision theory. 

The topic also introduces practical ways to measure rate and how to interpret data using graphs and gradients. You’ll study reaction profiles, activation energy, and the role of enzymes as biological catalysts.

You’ll also learn about reversible reactions and how dynamic equilibrium is reached in closed systems. The topic explains how changing temperature, pressure, or concentration affects the position of equilibrium, using ideas from Le Chatelier’s Principle. 

These concepts help explain how conditions are chosen in industrial chemical processes to increase the yield of useful products.

C6: Global Challenges

This topic looks at how chemistry helps solve global problems. You’ll explore how raw materials are extracted, including by carbon reduction, electrolysis, and biological methods. The topic covers how chemists use a life-cycle assessment (LCA) and recycling to evaluate the impact of materials on the environment. 

You’ll also learn about the role of crude oil in modern life, how it is separated and processed, and how cracking produces useful fuels and materials.

You’ll study how the atmosphere has changed over time and how human activity affects its composition. This includes the greenhouse effect, climate change, and pollution caused by burning fuels. 

The topic also covers how chemistry helps monitor environmental change and reduce harmful impacts, including ways to make water safe to drink using filtration and distillation techniques.

Physics Topics

• P1: Matter

• P2: Forces

• P3: Electricity and magnetism

• P4: Waves and radioactivity

• P5: Energy

• P6: Global challenges

P1: Matter

This topic begins with the particle model and how it explains the behaviour of solids, liquids, and gases. You’ll learn how this model developed through the work of scientists like Thomson, Rutherford, and Bohr, and how atomic structure includes subatomic particles such as protons, neutrons, and electrons. 

The topic also introduces the concept of density and how to calculate it using mass and volume.

You’ll explore how energy changes affect matter, including how heating a material changes its temperature or causes a change of state. This includes learning about specific heat capacity, specific latent heat, and internal energy. 

You’ll also study how gases behave in closed systems, including the relationship between pressure and temperature. Throughout the topic, you’ll consider the limitations of particle models and how they can be improved.

P2: Forces

This section covers various types of forces, such as gravity, friction, and air resistance, and This topic begins with motion. You’ll learn how to describe and measure speed, velocity, and acceleration, and how to use graphs to analyse motion. 

The topic explains the difference between scalar and vector quantities and how to apply equations for constant and accelerating motion. You’ll practise interpreting distance-time and velocity-time graphs and explore how forces affect moving objects.

You’ll then study Newton’s laws of motion and how forces cause changes in speed or direction. The topic covers contact and non-contact forces, free-body diagrams, resultant forces, and inertia. 

Finally, you’ll learn how forces can change the shape of objects. This includes stretching, compressing, and bending, with a focus on Hooke’s law and how to calculate spring constants and energy stored in springs. 

You’ll also study gravitational fields, the difference between weight and mass, and how the gravitational field strength varies between planets.

P3: Electricity and Magnetism

This topic begins with static electricity. You’ll learn how objects become charged through the transfer of electrons and how these charges cause attraction or repulsion. 

You’ll then study electric circuits and how current, potential difference, and resistance are measured and calculated. You’ll use circuit symbols to build series and parallel circuits, and investigate the behaviour of different components like diodes, thermistors, and LDRs. 

The topic also includes Ohm’s law and energy and power calculations, using graphs to explore how different circuit elements behave.

Finally, you’ll explore how electricity and magnetism are connected. You’ll study magnetic fields around magnets and current-carrying wires, and how solenoids are used to create strong magnetic effects. 

The topic covers the motor effect, how electric motors work, and how to use Fleming’s left-hand rule and equations to calculate the force on a wire in a magnetic field.

P4: Waves and Radioactivity

This topic begins with wave behaviour. You’ll learn how to describe waves using terms such as frequency, wavelength, amplitude, and period, and how to calculate wave speed. You’ll investigate wave reflection, refraction, and transmission using practical methods.

You’ll then study the electromagnetic spectrum, from radio waves to gamma rays. You’ll learn how different types of electromagnetic waves are used in communication, medicine, and industry, and how wave frequency and wavelength affect their properties. The topic also covers how electromagnetic waves transfer energy and how some types, like ultraviolet or X-rays, can be hazardous to living tissue.

Finally, you’ll explore radioactivity and how unstable atomic nuclei emit radiation. This includes the properties and uses of alpha, beta, and gamma radiation, and how to write nuclear equations to show radioactive decay. 

You’ll study the concept of half-life and how it relates to the random nature of decay, as well as the differences between contamination and irradiation and how to manage radiation safely.

P5: Energy

This topic explores how energy is stored, transferred, and conserved in physical systems. You’ll learn how to describe and calculate energy changes in situations like moving objects, falling objects, heating, and using electrical appliances. 

You’ll also study power and efficiency. This includes how to calculate energy efficiency in appliances, how energy is dissipated as waste, and how to reduce unwanted transfers using lubrication and insulation. 

You’ll learn how power ratings relate to energy changes in domestic devices, and how insulation affects the rate of cooling. Throughout the topic, practical investigations help you understand how to measure and improve energy use in real systems.

P6: Global Challenges

This topic shows how physics can be applied to solve global problems and improve lives. You’ll study how motion concepts such as speed, acceleration, and deceleration apply to real-world situations like transport safety. The topic explains how reaction time, thinking and braking distances affect stopping distance.

You’ll also explore how electricity is generated, transferred, and used efficiently. This includes renewable and non-renewable energy sources, changes in energy use over time, and how the National Grid transfers electricity using transformers. The topic covers mains electricity, plug wiring, the difference between AC and DC, and how to use physics to reduce energy waste and increase safety at home and in industry.

CS7: Practical Skills (For All Subjects)

This topic helps you build the practical skills needed in Biology, Chemistry, and Physics. You’ll learn how to plan, carry out, and evaluate experiments safely and accurately. 

This includes using laboratory equipment like: 

• Microscopes

• Bunsen burners

• Measuring cylinders

• Thermometers to take measurements such as time, temperature, mass, and pH.

You’ll also develop skills in making observations, recording results, and interpreting data. Across all three sciences, you’ll investigate things like the rate of photosynthesis, electrolysis, rates of reaction, and wave behaviour using ripple tanks. 

These experiments link directly to the content you study and help you apply science to real-life situations.

OCR Paper Structure

Foundation tier papers (1–6) target grades 1–5, and Higher tier papers (7–12) target grades 4–9. 

Each paper is a 1 hour 10 minute written exam worth 60 marks (16.7% of the GCSE), with a mix of multiple choice, short answer, calculation and extended response questions. 

How to Turn This Into a Revision Plan

• Confirm your exam board and tier before you start. 

• Go topic by topic and mark each one Confident, Needs Work, or Not Yet Covered.

• Tackle "Not Yet Covered" topics first, since they're the biggest risk.

• Move on to "Needs Work" topics using past paper questions and targeted practice.

• Revisit "Confident" topics occasionally. Content from early in the course fades if you don't return to it.

• Remember that required practicals are examinable. Questions can ask you to describe method, identify variables, or evaluate results from any required practical on your specification.

Revision Resources for Combined Science 

• AQA GCSE Combined Science: Trilogy Revision

• Edexcel GCSE Combined Science Revision 

• OCR GCSE (9–1) in Combined Science A (Gateway Science) Revision

Frequently Asked Questions

How many GCSEs is Combined Science worth? 

Combined Science is worth two GCSEs, awarded as a double grade (for example, 7-7 or 5-4), based on your marks across all six papers.

What's the difference between Combined Science and Triple Science? 

Triple Science covers Biology, Chemistry and Physics as three separate GCSEs, with more content in each subject. Combined Science covers a reduced version of the same three subjects across two GCSEs.

Do all three exam boards cover the same content? 

No. AQA, Edexcel and OCR organise topics differently and don't test identical content, even though there's significant overlap. Always revise from your own board's specification.

Get Exam-Ready With Save My Exams

Combined Science is hard because you're holding Biology, Chemistry and Physics in your head at once, across six separate papers, and switching between them fast.

The topic lists above are your map. Use them to check off what you've covered in each subject, so nothing gets left until the last minute by accident.

Then build speed with Save My Exams' topic questions and past papers, sorted by subject and exam board. Working through them regularly keeps all three sciences active in your memory, instead of cramming one subject and letting the others go cold.

Revision notes fill any gaps you find along the way, written to match your specification so you're never revising content that won't come up.

Good luck.

References

AQA GCSE Combined Science Trilogy (8464) specification  (opens in a new tab)

Edexcel GCSE (9-1) combined science (1SC0) specification (opens in a new tab)

OCR GCSE (9–1) in Combined Science A (Gateway Science) specification (opens in a new tab)