A Level Biology Topics by Exam Board: Full List

As a biology teacher, I understand how extensive the major A Level Biology specifications can be, and how overwhelming it can feel to revise such a large volume of content. 

Here at Save My Exams, we’ve put together this guide to help you navigate the key areas you need to cover for your exams. Whether you're just starting your revision or trying to fill in gaps, this article will give you a clear overview of the essential topics, helping you make the most productive use of your revision time.

Specifications covered in this article include:

• AQA A Level Biology

• OCR A Level Biology

• Edexcel SNAB

• CIE A Level Biology

AQA A Level Biology Topics

1.Biological Molecules

This topic explores the fundamental molecules that make up living organisms. It examines how carbohydrates, lipids, proteins, nucleic acids and water contribute to the structure and function of cells. It also introduces ATP and discusses some of the inorganic ions that are essential in biological systems.

Subtopics include:

• Monomers and polymers

• Carbohydrates

• Lipids

• Proteins, including enzymes

• Nucleic acids

• ATP

• Water

• Inorganic ions

2.Cells

Students study cell structure, the differences between prokaryotic and eukaryotic cells, microscopy and virus structure. This topic also introduces cell division, including mitosis and binary fission, along with membrane transport and the function of the immune system. 

Subtopics include:

• Cell structure

• All cells arise from other cells

• Transport across cell membranes

• Cell recognition and the immune system

3.Organisms exchange substances with their environment

This topic focuses on the mechanisms by which organisms exchange essential substances with their surroundings. It includes surface area to volume ratio, gas exchange systems, digestion, absorption, and mass transport in both animals and plants. 

Subtopics include:

• Surface area to volume ratio

• Gas exchange

• Digestion and absorption

• Mass transport

4.Genetic information, variation and relationships between organisms

Students examine how genetic information is stored, expressed and inherited, and how variation and biodiversity arise. It also includes methods used to classify organisms and measure diversity.

Subtopics include:

• DNA, genes and chromosomes

• DNA and protein synthesis

• Genetic diversity can arise as a result of mutation or during meiosis

• Genetic diversity and adaptation

• Species and taxonomy

• Biodiversity within a community

• Investigating diversity

5.Energy transfers in and between organisms

This section is on capture, transfer, and use of energy in living organisms. It includes the biochemical processes of photosynthesis and respiration, as well as the transfer of energy and nutrients through ecosystems. 

Subtopics include:

• Photosynthesis

• Respiration

• Energy and ecosystems

• Nutrient cycles

6.Organisms respond to changes in their internal and external environments

This topic explores how organisms detect and respond to stimuli using nervous and hormonal systems. It also includes muscle contraction and the principles and mechanisms of homeostasis in the regulation of internal conditions.

Subtopics include:

• Stimuli, both internal and external, are detected and lead to a response

• Nervous coordination

• Skeletal muscles are stimulated to contract by nerves and act as effectors

• Homeostasis is the maintenance of a stable internal environment
  

7.Genetics, populations, evolution and ecosystems

Students learn about inheritance patterns, population genetics, the mechanisms of evolution and how organisms interact within ecosystems. 

Subtopics include:

• Inheritance

• Populations

• Evolution may lead to speciation

• Populations in ecosystems

8.The control of gene expression

This final topic investigates how gene expression is regulated and how gene technologies are used in medicine and research. It covers mutations, epigenetics, cancer, genome projects and modern applications of recombinant DNA technology.

Subtopics include:

• Alteration of the sequence of bases in DNA can alter the structure of proteins

• Gene expression is controlled by a number of features

• Using genome projects

• Gene technologies

What is Covered in AQA A Level Biology Papers?

Revision Resources for AQA A Level biology

I am one member of a team of expert biology teachers here at Save My Exams, and we spend our time producing exam-specific revision notes, exam questions, videos and flashcards to aid students in their revision. You can access AQA A Level biology resources, along with past papers and more, by following the links below:

• AQA A Level Biology Revision Notes

• AQA A Level Biology Exam Questions

• AQA A Level Biology Mock Exams

• AQA A Level Biology Past Papers

OCR A Level Biology Topics

1.Development of Practical Skills in Biology

This module focuses on the practical skills required for studying biology at A Level. It supports students in designing, carrying out, analysing and evaluating experiments, including the application of mathematical techniques. 

Subtopics include:

• Practical skills assessed in a written examination

• Practical skills assessed in the Practical Endorsement

2.Foundations in Biology

This module lays the groundwork for understanding the structure and function of cells and the molecules that make life possible. Students also explore biological membranes and the cell cycle. 

Subtopics include:

• Cell structure

• Biological molecules

• Nucleotides and nucleic acids

• Enzymes

• Biological membranes

• Cell division, cell diversity and cellular organisation

3.Exchange and Transport

Focusing on the need for specialised exchange surfaces and transport systems in multicellular organisms, this module covers gas exchange and transport in both animals and plants.

Subtopics include:

• Exchange surfaces

• Transport in animals

• Transport in plants

4.Biodiversity, Evolution and Disease

This module explores the diversity of life, how it is classified and measured, and the mechanisms behind evolution. It also covers immunity and disease, including types of pathogens, and plant and animal defences. 

Subtopics include:

• Communicable diseases, disease prevention and the immune system

• Biodiversity

• Classification and evolution

5.Communication, Homeostasis and Energy

Students learn how organisms detect and respond to internal and external changes, focusing on homeostasis, neuronal and hormonal communication, and muscle physiology. The module also covers energy transfer through photosynthesis and respiration. 

Subtopics include: 

• Communication and homeostasis

• Excretion as an example of homeostatic control

• Neuronal communication

• Hormonal communication

• Plant and animal responses

• Photosynthesis

• Respiration

6.Genetics, Evolution and Ecosystems

This final module covers genetic control, inheritance patterns, biotechnology and ecosystem dynamics.

Subtopics include:

• Cellular control

• Patterns of inheritance

• Manipulating genomes

• Cloning and biotechnology

• Ecosystems

• Populations and sustainability

What is Covered in OCR A Level Biology Papers?

You can access OCR A Level biology resources containing past papers and more by following the links below:

• OCR A Level Biology Revision Notes

• OCR A Level Biology Exam Questions

• OCR A Level Biology Past Papers

Edexcel SNAB Topics

1.Lifestyle, Health and Risk

This topic explores the link between lifestyle factors and the risk of developing cardiovascular disease (CVD). In this context, students learn about heart structure, the cardiac cycle, blood vessels, and blood clotting.

The topic also introduces key biological molecules, such as carbohydrates and lipids, and their roles in diet and health. It emphasises the development of evaluation skills, particularly in assessing health risks, distinguishing correlation from causation, and interpreting data from scientific studies. 

Treatment strategies for CVD, along with their benefits and risks, are also discussed. 

2.Genes and Health

Using the context of cystic fibrosis, this topic focuses on cell membranes and transport mechanisms, gas exchange and enzyme function. Students examine DNA and RNA structure, DNA replication and protein synthesis. They also learn about inheritance patterns, gene mutations, and how mutations can lead to disease. 

The topic introduces genetic screening techniques and considers the ethical, legal and social issues associated with genetic testing.

3.Voice of the Genome

This topic considers how a single fertilised egg can develop into a complex multicellular organism. It looks at the structure of eukaryotic and prokaryotic cells, mitosis and meiosis, gamete structure and fertilisation. Students learn how differential gene expression leads to cell specialisation and tissue formation. 

The topic introduces the concept of stem cells, including their potential in medicine and the ethical debates surrounding their use. It also covers epigenetic mechanisms and the influence of the environment on phenotype.

4.Biodiversity and Natural Resources

This topic considers how biodiversity is measured and compared, and how species show adaptation to their environment. Students apply the Hardy–Weinberg equation and examine how organisms are classified based on phenotype and genotype.

The topic also covers plant cell structure, the use of plant fibres and chemical extracts, and how new drugs are developed. 

It concludes with conservation strategies, including the roles of seed banks and zoos in protecting biodiversity and genetic diversity.

5.On the Wild Side

This ecology-based topic looks at the role of photosynthesis in supporting ecosystems, and at the flow of energy through trophic levels. Students learn about primary productivity and energy transfer efficiency.

The effects of climate change on species distribution and life cycles are considered, and students explore the processes of succession and speciation. 

There is also a focus on how science informs environmental decision-making and how models and data are used to support or refute scientific conclusions.

6.Immunity, Infection and Forensics

This topic combines immunology with forensic science. Students learn how pathogens, such as bacteria and viruses, infect the body and how the immune system defends against them. Key immune processes, including the roles of white blood cells and antibodies, are explored in depth. 

The topic also examines DNA profiling, determining the time of death, and the decomposition process. 

Students consider the evolutionary arms race between pathogens and hosts, antibiotic resistance, and hospital-acquired infections, with an emphasis on prevention and control.

7.Run for Your Life

This topic explores how the body responds to physical activity. Students study muscle structure and contraction, as well as the biochemical pathways of aerobic and anaerobic respiration. The topic explains how heart rate is regulated and how internal conditions are controlled by negative feedback. 

Data from exercise experiments are used to analyse physiological responses, and the topic concludes with a discussion of performance-enhancing drugs in sport.

8.Grey Matter

This topic explores the structure and function of the nervous system, including nerve impulses, synaptic transmission, and brain structure and development. Students examine learning through habituation, the role of IAA in plants, and techniques for investigating brain function. The topic also covers applications of genome sequencing and genetic modification, alongside associated ethical issues.

What is Covered in Edexcel SNAB A Level Biology Papers?

You can access Edexcel SNAB resources containing past papers and more by following the links below:

• Edexcel SNAB Revision Notes

• Edexcel SNAB Exam Questions

• EDX SNAB Past Papers

CIE A Level Biology Topics

1.Cell Structure

This topic introduces the basic unit of life—the cell. Students learn to distinguish between prokaryotic and eukaryotic cells, identify organelles and their functions, and understand the use of microscopes. The topic also addresses viruses as non-cellular structures.

2.Biological Molecules

Students explore key organic molecules, such as carbohydrates, lipids and proteins, examining how their molecular structures relate to function. Water and its properties are studied as a vital biological solvent. The topic also covers qualitative food tests to identify biological molecules.

3.Enzymes

This topic focuses on enzyme structure and function, including the lock-and-key and induced fit models. Students investigate how temperature, pH and other variables influence enzyme activity, and learn how enzymes are used in industrial and medical contexts, including immobilisation.

4.Cell Membranes and Transport

Students study the fluid mosaic model of membrane structure and the mechanisms by which substances move in and out of cells. These include diffusion, osmosis, active transport and endocytosis/exocytosis. Cell signalling and the importance of membrane proteins are also explored.

5.The Mitotic Cell Cycle

This topic explains how eukaryotic cells grow and divide through the mitotic cell cycle, including interphase, mitosis, and cytokinesis. Students study chromosome structure, the role of telomeres, and the function of stem cells. The consequences of uncontrolled cell division, such as tumour formation, are also introduced. 

6.Nucleic Acids and Protein Synthesis

Students explore the structure and roles of DNA and RNA in the storage and expression of genetic information. The processes of DNA replication, transcription and translation are covered, alongside the universal nature of the genetic code and the impact of mutations on protein function.

7.Transport in Plants

This topic explores how flowering plants transport water, mineral ions, and organic compounds within vascular tissue. Students examine the structure and function of xylem and phloem, the processes of transpiration and translocation, and adaptations that help reduce water loss.

8.Transport in Mammals

Focusing on the mammalian circulatory system, students study blood vessels, the structure and function of the heart, tissue fluid formation, and the role of blood in transporting oxygen and carbon dioxide. The structure and function of haemoglobin and the Bohr effect are also included.

9.Gas Exchange

This topic looks at the human gas exchange system, including lungs, bronchi, alveoli and associated tissues. Students learn how the structure of these components relates to function and how gases are exchanged between air and blood.

10.Infectious Diseases

Students investigate pathogens and their modes of transmission. Four major diseases—cholera, malaria, TB, and HIV/AIDS—are explored, in terms of cause, spread, prevention and control. The topic also includes antibiotic function and resistance.

11.Immunity

This topic outlines the immune response, including the roles of phagocytes, antigens, lymphocytes and antibodies. It also covers active and passive immunity, monoclonal antibodies, vaccination strategies, and how vaccines help control infectious diseases.

12.Energy and Respiration

Students study ATP as the universal energy currency, and examine the biochemical steps of aerobic and anaerobic respiration. Practical work reinforces these concepts through investigation of respiration rates.

13.Photosynthesis

Students study the structure of chloroplasts and the role of photosynthetic pigments, including chlorophyll and accessory pigments, in capturing light. The light-dependent and light-independent reactions are covered in detail, along with the factors that affect the rate of photosynthesis. Practical investigations help reinforce understanding of limiting factors. 

14.Homeostasis

Students learn about kidney structure and osmoregulation, blood glucose regulation, and cell signalling via hormones. The concept of negative feedback is central to these processes, allowing the body to detect and correct deviations from normal conditions.

The topic also includes plant responses to water stress and the role of guard cells and abscisic acid in stomatal regulation.

15.Control and Coordination

This topic explores nervous and hormonal coordination in animals and plants. Students study nerve impulses, synaptic transmission, muscle contraction, and the comparison of nervous vs endocrine systems. 

Plant responses, such as the Venus fly trap and plant hormone action, are also included.

16.Inheritance

This topic begins with meiosis as the basis of genetic variation and introduces the principles of monohybrid and dihybrid inheritance, including codominance, sex linkage and epistasis. Students learn how to analyse genetic crosses, interpret pedigree diagrams, and apply the chi-squared test to genetic data. The topic also covers the role of mutations and explores how genes are regulated

17.Selection and Evolution

This topic explains how variation within populations provides the basis for natural and artificial selection. Students learn how different types of selection, the founder effect, and genetic drift contribute to changes in allele frequencies and the formation of new species over time. The Hardy–Weinberg principle is used, and students consider the role played by DNA data in the study of evolution.

18.Classification, Biodiversity and Conservation

This topic includes the principles of taxonomy, modern classification using molecular evidence, and the importance of biodiversity at genetic, species, and ecosystem levels. It also addresses threats to biodiversity and outlines conservation strategies such as habitat management, captive breeding, and seed banks.

19.Genetic Technology

Students learn how DNA can be amplified, sequenced, and analysed using techniques such as PCR, electrophoresis, and gene probes. Applications include genetic modification, gene therapy, and the production of transgenic organisms. Ethical issues surrounding the use of genetic technologies are also considered. 

What is Covered in CIE A Level Biology Papers?

You can access CIE A Level biology resources containing past papers and more by following the links below:

• CIE A Level Biology Revision Notes

• CIE A Level Biology Exam Questions

• CIE A Level Biology Past Papers

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References

• AQA A Level Biology Specification

• OCR A Level Biology Specification

• Edexcel SNAB Specification

• CIE A Level Biology Specification