GCSE Biology Topics by Exam Boards: What Do You Need to Know

GCSE Biology might seem difficult from the start. One day you’re learning about cells and the next you’re somehow expected to understand ecosystems, genetics and the whole human body too. It’s a lot and it’s normal to feel like you don’t even know where to start.

This guide makes it simpler. It’s a clear list of GCSE Biology topics by exam board, so you can revise what actually comes up in your exams. One thing that catches loads of students out is this: not everyone studies the same Biology content. Your topics depend on your exam board. They can also change depending on whether you’re doing Combined Science or Separate Biology and whether you’re entered for Foundation or Higher.

Once you know those three things, your revision gets way more focused. And that’s the whole point of this guide.

AQA GCSE Biology Topics

If you’re following the AQA Biology course, your content is split across two main papers. Each paper tests a group of topics that build on one another, from tiny cells to whole ecosystems.

Topic 1: Cell Biology

Cell biology is about the tiny units of life called cells. You’ll learn what cells are made of, how they work and how they grow and divide. You’ll also cover how materials move in and out of cells.

Topic 2: Organisation

This links cells together into tissues, organs and systems. You’ll look at how the digestive and circulatory systems work and how plants move water and nutrients around.

Topic 3: Infection and Response

Here you explore diseases, how they spread and how the body defends itself. You’ll also see how vaccines and medicines help protect us.

Topic 4: Bioenergetics

This topic is all about energy in living things. You’ll study how plants make food in photosynthesis and how both plants and animals release energy in respiration.

Topic 5: Homeostasis and Response

Homeostasis is how the body keeps conditions steady, for example, temperature, water balance and blood sugar. You’ll also learn about the nervous and hormonal systems that control these processes.

Topic 6: Inheritance, Variation and Evolution

This section looks at how traits pass from parents to offspring, why organisms vary and how species change over time.

Topic 7: Ecology

Ecology is about living things in their environment. You’ll learn how species interact, how energy flows through ecosystems and why biodiversity matters.

Even though these topics are grouped by paper, many ideas link across them. Skills like analysing data and interpreting graphs show up in questions too, so it helps to revise both knowledge and how to use it.

Edexcel GCSE Biology Topics

If you’re studying Edexcel GCSE Biology, the course is split across two exam papers. Both Foundation and Higher tiers cover the same topic areas, but Higher papers go into more detail and include more challenging questions.

Topic 1: Key Concepts in Biology

This topic builds the basics you’ll use everywhere else. It covers cells, enzymes, microscopy and how scientists plan and analyse experiments.

Topic 2: Cells and Control

Here, you look at how cells work and how the body controls processes like blood sugar and hormones. You’ll also study the nervous system and the brain.

Topic 3: Genetics

This topic focuses on DNA, genes and inheritance. You’ll learn how characteristics are passed on and how genetic disorders can occur.

Topic 4: Natural Selection and Genetic Modification

You’ll explore evolution, selective breeding and how organisms adapt over time. This topic also introduces genetic engineering and its uses.

Topic 5: Health, Disease and the Development of Medicines

This topic is all about what makes us ill, how the body fights back and how we treat disease. You’ll learn the difference between bacteria, viruses, fungi and protists and how these pathogens spread. You’ll also cover the immune system, including things like white blood cells, antibodies and how vaccinations help protect you. Then it moves into medicine, where you look at antibiotics, painkillers and how new drugs are developed, tested and approved. This is where you’ll also need to understand ideas like clinical trials, placebos and why testing has to be fair and reliable.

Topic 6: Plant Structures and Their Functions

This topic helps you understand how plants survive and grow without a brain or a heart. You’ll cover photosynthesis, including how plants use light, carbon dioxide and water to make glucose. You’ll also learn how plants transport water and minerals from roots to leaves and how sugars move around the plant to support growth. There’s a big focus on plant tissues like xylem and phloem, plus how leaves are adapted for gas exchange. You’ll also look at factors that affect photosynthesis, which often come up in graph and data questions.

Topic 7: Animal Coordination, Control and Homeostasis

Homeostasis is essentially the body’s mechanism for maintaining stability, even when the environment changes. In this topic, you’ll learn how the nervous system and hormones help control the body. You’ll look at things like reflexes, the brain, and how signals travel. Then you’ll cover key examples of homeostasis, such as controlling body temperature, balancing water levels, and maintaining stable blood glucose levels. Questions here often test how different organs work together, not just one process on its own.

Topic 8: Exchange and Transport in Animals

This topic is about how the body moves substances in and out of cells and why structure matters. You’ll study gas exchange in the lungs, including how alveoli are adapted for efficient diffusion. You’ll also cover the circulatory system, looking at the heart, blood vessels and how blood transports oxygen, nutrients, carbon dioxide and hormones. A lot of the marks come from explaining why the system is efficient, so it’s not just “what happens”, but “why it works”.

Topic 9: Ecosystems and Material Cycles

This final topic looks at ecosystems, food chains, biodiversity and how materials like carbon and water cycle through the environment.

WJEC GCSE Biology Topics

If you’re studying WJEC, this section really matters. Unlike some exam boards, WJEC Biology is organised into clear units with numbered topics and exam questions often stick closely to this structure. Knowing these numbers helps you revise more accurately.

Unit 1: Cells, Organ Systems and Ecosystems

Unit 1 focuses on the basics of life, how organisms are organised and how living things interact with their environment.

• 1.1 Cells and movement across membranes
  You’ll learn about animal and plant cells, specialised cells and how substances move in and out by diffusion, osmosis and active transport.
• 1.2 Respiration and the respiratory system
  This covers aerobic and anaerobic respiration, plus how the lungs are adapted for gas exchange.
• 1.3 Digestion and the digestive system
  You’ll study enzymes, digestion in the human body and how nutrients are absorbed.
• 1.4 Circulatory system and transport in plants
  This topic looks at the heart, blood vessels and blood, alongside plant transport systems like xylem and phloem.
• 1.5 Ecosystems, energy flow and nutrient cycles
  You’ll explore food chains, food webs, pyramids of biomass and cycles such as the carbon cycle.
• 1.6 Human impact on ecosystems
  This section focuses on pollution, biodiversity, conservation and how humans affect the environment.
  

Unit 2: Variation, Homeostasis and Micro-organisms

Unit 2 moves into genetics, control systems and how the body responds to internal and external changes.

• 2.1 Variation and inheritance
  You’ll learn how characteristics are passed on, including genes, DNA and inherited conditions.
• 2.2 Evolution and natural selection
  This topic explains how species change over time and how natural selection works.
• 2.3 Micro-organisms and disease
  You’ll study bacteria, viruses, fungi and how they cause disease, as well as how disease spreads.
• 2.4 Defence against disease
  This covers the immune system, white blood cells, antibodies and vaccination.
• 2.5 Nervous system and hormonal control
  You’ll learn how the body uses nerves and hormones to respond to changes.
• 2.6 Homeostasis
  This focuses on keeping internal conditions stable, such as body temperature and water balance.
• 2.7 Control of blood glucose
  A key topic on hormones like insulin and glucagon and how blood sugar levels are regulated.
• 2.8 Plant hormones and responses
  You’ll look at plant responses, including tropisms and the role of hormones like auxins.
  

Unit 3: Practical Assessment

Unit 3 is a centre-based practical assessment that is externally marked. You’ll carry out practical work in school and your understanding of methods, results and conclusions is assessed. It’s not about memorising experiments, but about showing you can plan, carry out and evaluate practical biology properly.

OCR GCSE Biology Topics

OCR Biology is where a lot of students get confused, because there are two different specifications. They cover similar ideas, but the structure and topic names are different. Make sure you know which one you’re doing before revising.

OCR Gateway (Biology A – J247) Topics

OCR Gateway Biology is organised into seven main topics, labelled B1 to B7. Each one builds from basic biology to bigger environmental ideas.

• B1: Cell-level systems
  Cells, microscopy, enzymes, and how substances move in and out of cells.
• B2: Scaling up
  How cells work together in tissues, organs, and organ systems, including transport in animals and plants.
• B3: Organism-level systems
  Key systems include digestion, breathing, circulation, and the nervous system.
• B4: Community level systems
  Ecosystems, biodiversity, food chains, and how organisms interact with each other.
• B5: Genes, inheritance and selection
  DNA, genes, inheritance, variation, and natural selection.
• B6: Global challenges
  Big-picture biology, such as disease, climate change, food security, and sustainability.
• B7: Practical skills
  Practical work and scientific skills are assessed across exams.
  

OCR Twenty-First Century (Biology B – J257) Chapters

OCR Twenty-First Century Biology is split into eight chapters, also labelled B1 to B8. The content is often taught through real-life contexts.

• B1: You and your genes
  DNA, inheritance and genetic variation.
• B2: Keeping healthy
  Disease, the immune system and lifestyle factors that affect health.
• B3: Living together – food and ecosystems
  Ecosystems, food production and how humans manage resources.
• B4: Using food and controlling growth
  Respiration, photosynthesis and growth in plants and animals.
• B5: The human body – staying alive
  Organ systems such as digestion, circulation and gas exchange.
• B6: Life on Earth – past, present and future
  Evolution, extinction and how species change over time.
• B7: Ideas about Science
  How scientific ideas develop, including risk, ethics and the quality of evidence. This is assessed through questions linked to biology topics, not as a standalone exam.
• B8: Practical skills
  Planning experiments, analysing data and evaluating results.

What GCSE Biology Topics Overlap Across Most Exam Boards

No matter which exam board you’re on, a lot of GCSE Biology covers the same core ideas. That’s good news, because it means revision in one area often helps in another.

Across most exam boards, you’ll study cells and how they work, including the role of enzymes. Respiration comes up in every course, focusing on how living things release energy. You’ll also learn about genetics and inheritance, explaining how features pass from parents to offspring. Ecosystems and the relationships between organisms appear widely, alongside homeostasis, where the body keeps internal conditions stable. Topics around disease and health, such as pathogens, immunity and treatments are also common.

These shared topics give you a solid foundation. Still, the detail and exam style can vary, so always check your exam board topic list above to make sure you’re revising exactly what you need.

Conclusion

GCSE Biology can feel much more manageable once you know exactly what you need to revise. Breaking the subject down by exam board helps you focus on the right topics and avoid wasting time on content that won’t come up. While many ideas overlap across boards, the detail and exam style still matter, so always double-check your own specification before revising.

If you’re finding certain topics tricky or want extra confidence before exams, support from GCSE Biology online tutors can make a real difference. A good tutor can explain difficult ideas clearly, help you practise exam questions and keep your revision on track. With the right plan and support, GCSE Biology becomes far less overwhelming and much easier to tackle.

FAQs

What topics are in GCSE Biology?

GCSE Biology covers how living things work, from cells right up to ecosystems. Most exam boards include topics such as:

• Cells and enzymes
• Organisation in plants and animals
• Infection, disease and immunity
• Photosynthesis and respiration
• Homeostasis and control
• Genetics, inheritance, and evolution
• Ecosystems, biodiversity and human impact

The exact content depends on your exam board and whether you study Combined Science or Separate Biology, plus Foundation or Higher tier.

What topics are in Biology Paper 1 AQA GCSE?

AQA GCSE Biology Paper 1 covers:

• Cell biology
• Organisation
• Infection and response
• Bioenergetics

These topics focus on how cells function, how organisms are organised, how diseases affect the body and how energy moves through living things.

What topics are in Biology Paper 2 AQA GCSE?

AQA GCSE Biology Paper 2 covers:

• Homeostasis and response
• Inheritance, variation, and evolution
• Ecology

This paper looks at control systems in the body, genetics, evolution, and how organisms interact with their environment.

How many topics are there in GCSE Biology?

The number of topics depends on the exam board:

• AQA: 7 topics
• Edexcel: 9 topics
• OCR Gateway: 7 topics
• OCR Twenty First Century: 8 topics
• WJEC: 2 main units plus a practical assessment

Even though the structure changes, many core ideas overlap. Always revise using your own exam board specification to stay focused.