IGCSE Biology Topics by Exam Board: Full List

Biology is a subject that explains how living things work, from cells and organs to ecosystems and genetics. But when you’re revising for your IGCSE Biology exams, it can be hard to keep track of all the topics you need to cover, especially since the content can vary slightly depending on your exam board.

That’s why we’ve created this guide, which lays out the full list of IGCSE Biology topics for both Edexcel and Cambridge (CIE). Whether you’re aiming for a top grade or trying to fill in some knowledge gaps, this article will help you revise smarter and faster by showing you exactly what to focus on.

Specifications Covered in this Article:

• Edexcel International GCSE in Biology (opens in a new tab)

• CIE IGCSE Biology (0610 (opens in a new tab))

Edexcel IGCSE Biology Topics

1. The Nature and Variety of Living Organisms

Students learn the characteristics shared by all living organisms, and how different types (plants, animals, fungi, bacteria, protoctists and viruses) vary in structure and function.

Subtopics include:

• Characteristics of living things

• Eukaryotic and prokaryotic organisms

• Pathogens and disease-causing microorganisms

2. Structure and Functions in Living Organisms

This core topic explores how cells, tissues, organs and systems are structured and how they work together to support life processes.

Subtopics include:

• Levels of organisation

• Cell structures and functions

• Movement of substances (diffusion, osmosis, active transport)

• Nutrition in plants and humans

• Respiration (aerobic and anaerobic)

• Gas exchange systems

• Transport in plants and animals

• Excretion and homeostasis

• Coordination and response (including hormonal and nervous control)

3. Reproduction and Inheritance

Students learn about both sexual and asexual reproduction in plants and humans, and how traits are passed from one generation to the next.

Subtopics include:

• Pollination and seed formation

• The menstrual cycle and human development

• Genetic inheritance, DNA, and variation

• Mitosis, meiosis, and mutation

4. Ecology and the Environment

This section focuses on how organisms interact with each other and their environment.

Subtopics include:

• Habitats, populations, and ecosystems

• Food chains, food webs, and energy transfer

• The carbon and nitrogen cycles

• Human impact on the environment (pollution, greenhouse gases, eutrophication)

5. Use of Biological Resources

Students explore how biological knowledge is used in food production, selective breeding, cloning, and genetic engineering.

Subtopics include:

• Crop yield and pest control

• Industrial fermentation and fish farming

• Genetic modification and cloning

CIE IGCSE Biology Topics

1. Characteristics and Classification of Living Organisms

Students are introduced to the essential features that define life and how living organisms are grouped and named.

Subtopics include:

• Characteristics of living things (MRS GREN)

• The concept of classification and species

• The binomial naming system

• Use of dichotomous keys

• Features of major groups: vertebrates, arthropods, flowering plants, viruses, bacteria, fungi, protoctists

2. Organisation of the Organism

This topic explores the structure and function of cells and how cells are organised into tissues, organs, and systems.

Subtopics include:

• Comparison of animal, plant, and bacterial cells

• Structure and function of organelles

• Specialised cells and their functions

• Hierarchy: cells → tissues → organs → organ systems

• Calculating magnification and converting units

3. Movement into and out of Cells

Students learn about how substances move across cell membranes using different transport mechanisms.

Subtopics include:

• Diffusion and its role in biological systems

• Osmosis and water potential

• Effects of solutions on plant and animal cells

• Active transport and the role of carrier proteins

• Factors affecting the rate of transport

4. Biological Molecules

This topic covers the chemical building blocks of life and how we test for them.

Subtopics include:

• Elements in carbohydrates, proteins, and lipids

• Formation of large molecules from smaller units

• Food tests for starch, sugars, protein, fat, and vitamin C

• Structure of DNA

5. Enzymes

Students explore the structure, function and importance of enzymes in biological systems.

Subtopics include:

• Enzymes as biological catalysts

• Lock-and-key model

• Effects of temperature and pH on enzyme activity

• Denaturation and optimum conditions

6. Plant Nutrition

This topic explains how plants make their own food through photosynthesis.

Subtopics include:

• Photosynthesis equation (word and balanced symbol)

• Roles of chlorophyll, light, and carbon dioxide

• Products and uses of glucose

• Mineral requirements: magnesium and nitrates

• Leaf structure adaptations

• Investigations on limiting factors and gas exchange

7. Human Nutrition

Students learn how humans obtain and digest food to provide energy and materials for growth.

Subtopics include:

• Components of a balanced diet and deficiency diseases

• Human digestive system structure and functions

• Physical and chemical digestion

• Roles of enzymes: amylase, protease, lipase

• Absorption in the small intestine and structure of villi

• Functions of bile and the role of the liver

8. Transport in Plants

This topic explores how substances move through a plant.

Subtopics include:

• Functions of xylem and phloem

• Structure and positioning in roots, stems, and leaves

• Water uptake and root hair cells

• Pathway of water through the plant

• Transpiration and factors affecting its rate

• Mechanism of water movement

• Translocation of sucrose and amino acids

9. Transport in Animals

Students study how the circulatory system transports substances around the body.

Subtopics include:

• Double circulation in mammals

• Structure and function of the heart

• Coronary heart disease and risk factors

• Arteries, veins, and capillaries

• Blood components and their functions

• Immune system: phagocytes, lymphocytes, and antibodies

• Vaccination and memory cells

• Blood clotting

10. Diseases and Immunity

This topic introduces the body's defence mechanisms and the spread of diseases.

Subtopics include:

• Pathogens and methods of transmission

• Body barriers: skin, mucus, stomach acid

• Active and passive immunity

• Vaccination process and benefits

• Cholera and its effects

11. Gas Exchange in Humans

Students examine how humans exchange gases with the environment.

Subtopics include:

• Structure and adaptations of the gas exchange system

• Differences between inspired and expired air

• Role of the diaphragm and intercostal muscles

• Gas exchange in alveoli

• Effects of exercise on breathing

• Function of mucus and cilia in defence

12. Respiration

This topic explores how cells release energy from food.

Subtopics include:

• Definition and uses of energy in organisms

• Word and balanced equations for aerobic respiration

• Anaerobic respiration in yeast and muscle cells

• Oxygen debt and lactic acid

• Investigations using seeds or yeast

13. Excretion in Humans

Students learn how waste products are removed from the body.

Subtopics include:

• Organs of excretion: lungs, kidneys, skin

• Structure and function of the urinary system

• Nephron structure: filtration and reabsorption

• Formation of urine and role of ADH

• Deamination in the liver

14. Coordination and Response

This topic explains how organisms respond to changes inside and outside their bodies.

Subtopics include:

• Central and peripheral nervous system

• Reflex arcs and neurones

• Structure and function of synapses

• Eye structure and focusing

• Hormonal control: adrenaline, insulin

• Negative feedback and homeostasis

• Temperature regulation and skin structures

• Tropisms and auxin action in plants

15. Drugs

Students explore the effects of different types of drugs on the body.

Subtopics include:

• Definition and types of drugs

• Use of antibiotics and resistance
  Effects of recreational drugs (e.g. alcohol, heroin)

16. Reproduction

This topic covers both asexual and sexual reproduction in plants and animals.

Subtopics include:

• Definitions and differences between reproduction types

• Flower structure and pollination

• Fertilisation and seed formation

• Seed germination requirements

• Male and female reproductive systems in humans

• Menstrual cycle and hormonal regulation

• Development of the fetus and the role of the placenta

• Secondary sexual characteristics

17. Inheritance

Students study how genetic information is passed from one generation to the next.

Subtopics include:

• DNA structure and chromosomes

• Genes, alleles, genotype, and phenotype

• Monohybrid crosses and Punnett squares

• Sex determination

• Mitosis and meiosis

• Genetic variation and mutation

18. Variation and Selection

This topic explores the causes of variation and the process of natural selection.

Subtopics include:

• Genetic and environmental variation

• Darwin’s theory of evolution
  Antibiotic resistance in bacteria

19. Organisms and their Environment

Students study how organisms interact with each other and their surroundings.

Subtopics include:

• Definitions: population, community, habitat, ecosystem

• Measuring population size using quadrats

• Abiotic and biotic factors affecting distribution

20. Human Influences on Ecosystems

This topic investigates how human activities affect the environment.

Subtopics include:

• Air pollution: carbon monoxide and sulfur dioxide

• Greenhouse gases and global warming

• Water pollution: sewage and eutrophication

• Effects of deforestation

21. Biotechnology and Genetic Modification

Students explore how humans use living organisms and genetic technologies.

Subtopics include:

• Industrial fermenters and aseptic technique

• Production of yoghurt and insulin

• Genetic modification and transgenic organisms

• Micropropagation (tissue culture)

• Cloning animals and their uses

What is Covered in the IGCSE Biology Papers?

Edexcel IGCSE Biology Assessment:

CIE IGCSE Biology Assessment:

Revision Resources

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• Edexcel IGCSE Biology Revision Notes

• Edexcel IGCSE Biology Topic Questions and Model Answers

• Edexcel IGCSE Biology Flashcards

• Edexcel IGCSE Biology Past Papers and Mark Schemes

• CIE IGCSE Biology Revision Notes

• CIE IGCSE Biology Topic Questions and Model Answers

• CIE IGCSE Biology Flashcards

• CIE IGCSE Biology Past Papers and Mark Schemes

Explore all IGCSE Biology Resources:

• Edexcel IGCSE Biology

• CIE IGCSE Biology

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References

Edexcel IGCSE Specification (opens in a new tab)

CIE IGCSE Specification (opens in a new tab)