Source: https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-7-epigenetics-and-disease [Revision notes](https://senecalearning.com/en-gb/revision-notes.md) › [A Level](https://senecalearning.com/en-gb/revision-notes/a-level.md) › [Biology](https://senecalearning.com/en-gb/revision-notes/a-level/biology.md) › [AQA](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa.md) › Epigenetics & Disease # Epigenetics & Disease Biology: AQA A Level, topic 8.2.7 ## Causing Disease Epigenetics can cause disease if they are not controlled properly. ### Abnormal methylation ![Abnormal methylation](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/AQA%20New%20Modules/6.3.1/cancerous%20cells.jpg) - Epigenetic changes can cause diseases (e.g. cancer). - Methyl groups are epigenetic markers that bind to DNA to inhibit transcription. - Methyl groups are important in regulating processes like cell division. - If methylation is not regulated properly, this can affect the regulation of these important processes. This is called abnormal methylation. ### Increased methylation ![Increased methylation](https://image-v2.cdn.app.senecalearning.com/2018-08/af35e42f-6270-41fd-a99a-98707db5e73b/DNA-double-helix-.jpg) - If methylation is increased too much, it can decrease the gene expression of tumour suppressor genes more than normal. - Tumour suppressor genes prevent cell division from taking place. - If the genes are underexpressed, the cells divide uncontrollably and tumours are produced. ### Decreased methylation ![Decreased methylation](https://image-v2.cdn.app.senecalearning.com/2018-08/7a244485-48a9-47a6-98d6-2ff3ecf4455d/Tumour%20Cells.jpg) - If methylation is decreased too much, it can increase the gene expression of proto-oncogenes more than normal. - Proto-oncogenes promote cell division. - If the genes are overexpressed, the cells divide uncontrollably and tumours are produced. ## Treating Disease Epigenetics can also be used to treat disease because epigenetic markers can easily be removed. ### Epigenetic change ![Epigenetic change](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/2.2.1%20-%20Enzymes%201/protein.jpg) - Epigenetic changes that cause disease (e.g methylation leading to cancer) are temporary and can be reversed. - E.g. The action of the methyl transferase enzyme can be inhibited. Methyl transferase adds methyl groups (a type of epigenetic marker) to DNA to alter gene expression. If methylation is the cause of disease, inhibiting the enzyme can help treat the disease. ### Drugs and therapies ![Drugs and therapies](https://image-v2.cdn.app.senecalearning.com/2018-04/00b4ff94-e94c-43f0-b22f-38174ae4ca87/shutterstock_364107608.jpg) - The ability to reverse epigenetic change is important for designing new drugs and therapies. - Researchers are investigating how drugs can reverse the silencing or overexpression of genes. - Drugs that can reverse epigenetics can help return gene expression to its normal level. ### Future of epigenetics ![Future of epigenetics](https://image-v2.cdn.app.senecalearning.com/courseImages/biology/3.1.1%20-%20Pathogens/sneeze-min.jpg) - The understanding of epigenetics is increasing. - It is now understood that epigenetic change could play a role in conditions like allergies and autism. - In the future, using drugs that reverse epigenetic change could be used to treat many different conditions. ## Test yourself on Epigenetics & Disease - What is the effect of increased methylation on tumour suppressor genes? - Which of the following statements about abnormal methylation are true? - Which of the following statements about treating disease are true? - How do drugs and therapies return abnormal gene expression to its normal level? [Practise this topic for free](https://app.senecalearning.com/classroom/course/d0ce0c30-6417-11e8-8edc-d9cd1c890408/section/d34cc064-42d5-44df-808d-36b87f18f2ee/session) - Previous topic: [8.2.6 Epigenetics](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-6-epigenetics.md) - Next topic: [8.2.8 Regulating Translation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-8-regulating-translation.md) ## Biology: AQA A Level contents ### 1 Biological Molecules - 1.1 Monomers & Polymers - [1.1.1 Monomers & Polymers](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-1-1-monomers-and-polymers.md) - [1.1.2 Condensation & Hydrolysis Reactions](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-1-2-condensation-and-hydrolysis-reactions.md) - 1.2 Carbohydrates - [1.2.1 Structure of Carbohydrates](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-2-1-structure-of-carbohydrates.md) - [1.2.2 Types of Polysaccharides](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-2-2-types-of-polysaccharides.md) - [1.2.3 End of Topic Test - Monomers, Polymers and Carbs](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-2-3-end-of-topic-test-monomers-polymers-and-carbs.md) - [1.2.4 Exam-Style Question - Carbohydrates](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-2-4-exam-style-question-carbohydrates.md) - [1.2.5 A-A* (AO3/4) - Carbohydrates](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-2-5-a-a-ao34-carbohydrates.md) - 1.3 Lipids - [1.3.1 Triglycerides & Phospholipids](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-3-1-triglycerides-and-phospholipids.md) - [1.3.2 Types of Fatty Acids](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-3-2-types-of-fatty-acids.md) - [1.3.3 Testing for Lipids](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-3-3-testing-for-lipids.md) - [1.3.4 Exam-Style Question - Fats](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-3-4-exam-style-question-fats.md) - [1.3.5 A-A* (AO3/4) - Lipids](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-3-5-a-a-ao34-lipids.md) - 1.4 Proteins - [1.4.1 The Peptide Chain](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-1-the-peptide-chain.md) - [1.4.2 Investigating Proteins](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-2-investigating-proteins.md) - [1.4.3 Primary & Secondary Protein Structure](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-3-primary-and-secondary-protein-structure.md) - [1.4.4 Tertiary & Quaternary Protein Structure](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-4-tertiary-and-quaternary-protein-structure.md) - [1.4.5 Enzymes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-5-enzymes.md) - [1.4.6 Factors Affecting Enzyme Activity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-6-factors-affecting-enzyme-activity.md) - [1.4.7 Enzyme-Controlled Reactions](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-7-enzyme-controlled-reactions.md) - [1.4.8 End of Topic Test - Lipids & Proteins](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-8-end-of-topic-test-lipids-and-proteins.md) - [1.4.9 A-A* (AO3/4) - Enzymes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-9-a-a-ao34-enzymes.md) - [1.4.10 A-A* (AO3/4) - Proteins](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-10-a-a-ao34-proteins.md) - [1.4.11 Diagnostic Misconceptions - Enzyme Inhibitors](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-4-11-diagnostic-misconceptions-enzyme-inhibitors.md) - 1.5 Nucleic Acids - [1.5.1 DNA & RNA](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-5-1-dna-and-rna.md) - [1.5.2 Nucleotides](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-5-2-nucleotides.md) - [1.5.3 Polynucleotides](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-5-3-polynucleotides.md) - [1.5.4 DNA Replication](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-5-4-dna-replication.md) - [1.5.5 Exam-Style Question - Nucleic Acids](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-5-5-exam-style-question-nucleic-acids.md) - [1.5.6 A-A* (AO3/4) - Nucleic Acids](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-5-6-a-a-ao34-nucleic-acids.md) - 1.6 ATP - [1.6.1 Structure of ATP](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-6-1-structure-of-atp.md) - [1.6.2 Hydrolysis of ATP](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-6-2-hydrolysis-of-atp.md) - [1.6.3 Resynthesis of ATP](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-6-3-resynthesis-of-atp.md) - [1.6.4 End of Topic Test - Nucleic Acids & ATP](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-6-4-end-of-topic-test-nucleic-acids-and-atp.md) - 1.7 Water - [1.7.1 Importance of Water](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-7-1-importance-of-water.md) - [1.7.2 Structure of Water](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-7-2-structure-of-water.md) - [1.7.3 Properties of Water](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-7-3-properties-of-water.md) - [1.7.4 A-A* (AO3/4) - Water](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-7-4-a-a-ao34-water.md) - 1.8 Inorganic Ions - [1.8.1 Inorganic Ions](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-8-1-inorganic-ions.md) - [1.8.2 End of Topic Test - Water & Inorganic Ions](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/1-8-2-end-of-topic-test-water-and-inorganic-ions.md) ### 2 Cells - 2.1 Cell Structure - [2.1.1 Introduction to Cells](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-1-introduction-to-cells.md) - [2.1.2 Eukaryotic Cells & Organelles](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-2-eukaryotic-cells-and-organelles.md) - [2.1.3 Eukaryotic Cells & Organelles 2](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-3-eukaryotic-cells-and-organelles-2.md) - [2.1.4 Prokaryotes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-4-prokaryotes.md) - [2.1.5 A-A* (AO3/4) - Organelles](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-5-a-a-ao34-organelles.md) - [2.1.6 Methods of Studying Cells](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-6-methods-of-studying-cells.md) - [2.1.7 Microscopes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-7-microscopes.md) - [2.1.8 End of Topic Test - Cell Structure](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-8-end-of-topic-test-cell-structure.md) - [2.1.9 Exam-Style Question - Cells](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-9-exam-style-question-cells.md) - [2.1.10 A-A* (AO3/4) - Cells](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-1-10-a-a-ao34-cells.md) - 2.2 Mitosis & Cancer - [2.2.1 Mitosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-2-1-mitosis.md) - [2.2.2 Stages of Mitosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-2-2-stages-of-mitosis.md) - [2.2.3 Investigating Mitosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-2-3-investigating-mitosis.md) - [2.2.4 Cancer](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-2-4-cancer.md) - [2.2.5 A-A* (AO3/4) - The Cell Cycle](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-2-5-a-a-ao34-the-cell-cycle.md) - 2.3 Transport Across Cell Membrane - [2.3.1 Cell Membrane Structure](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-1-cell-membrane-structure.md) - [2.3.2 A-A* (AO3/4) - Membrane Structure](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-2-a-a-ao34-membrane-structure.md) - [2.3.3 Diffusion](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-3-diffusion.md) - [2.3.4 Osmosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-4-osmosis.md) - [2.3.5 Active Transport](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-5-active-transport.md) - [2.3.6 End of Topic Test - Mitosis, Cancer & Transport](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-6-end-of-topic-test-mitosis-cancer-and-transport.md) - [2.3.7 Exam-Style Question - Membranes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-7-exam-style-question-membranes.md) - [2.3.8 A-A* (AO3/4) - Membranes & Transport](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-8-a-a-ao34-membranes-and-transport.md) - [2.3.9 A-A*- Mitosis, Cancer & Transport](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-3-9-a-a-mitosis-cancer-and-transport.md) - 2.4 Cell Recognition & the Immune System - [2.4.1 Immune System](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-1-immune-system.md) - [2.4.2 Phagocytosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-2-phagocytosis.md) - [2.4.3 T Lymphocytes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-3-t-lymphocytes.md) - [2.4.4 B Lymphocytes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-4-b-lymphocytes.md) - [2.4.5 Antibodies](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-5-antibodies.md) - [2.4.6 Primary & Secondary Response](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-6-primary-and-secondary-response.md) - [2.4.7 Vaccines](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-7-vaccines.md) - [2.4.8 HIV](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-8-hiv.md) - [2.4.9 Ethical Issues](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-9-ethical-issues.md) - [2.4.10 End of Topic Test - Immune System](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-10-end-of-topic-test-immune-system.md) - [2.4.11 Exam-Style Question - Immune System](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-11-exam-style-question-immune-system.md) - [2.4.12 A-A* (AO3/4) - Immune System](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-12-a-a-ao34-immune-system.md) - [2.4.13 Diagnostic Misconceptions - Humoral vs Cellular](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/2-4-13-diagnostic-misconceptions-humoral-vs-cellular.md) ### 3 Substance Exchange - 3.1 Surface Area to Volume Ratio - [3.1.1 Size & Surface Area](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-1-1-size-and-surface-area.md) - [3.1.2 A-A* (AO3/4) - Cell Size](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-1-2-a-a-ao34-cell-size.md) - 3.2 Gas Exchange - [3.2.1 Single-Celled Organisms](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-1-single-celled-organisms.md) - [3.2.2 Multicellular Organisms](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-2-multicellular-organisms.md) - [3.2.3 Control of Water Loss](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-3-control-of-water-loss.md) - [3.2.4 Human Gas Exchange](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-4-human-gas-exchange.md) - [3.2.5 Ventilation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-5-ventilation.md) - [3.2.6 Dissection](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-6-dissection.md) - [3.2.7 Measuring Gas Exchange](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-7-measuring-gas-exchange.md) - [3.2.8 Lung Disease](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-8-lung-disease.md) - [3.2.9 Lung Disease Data](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-9-lung-disease-data.md) - [3.2.10 End of Topic Test - Gas Exchange](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-10-end-of-topic-test-gas-exchange.md) - [3.2.11 A-A* (AO3/4) - Gas Exchange](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-2-11-a-a-ao34-gas-exchange.md) - 3.3 Digestion & Absorption - [3.3.1 Overview of Digestion](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-3-1-overview-of-digestion.md) - [3.3.2 Digestion in Mammals](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-3-2-digestion-in-mammals.md) - [3.3.3 Absorption](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-3-3-absorption.md) - [3.3.4 End of Topic Test - Substance Exchange & Digestion](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-3-4-end-of-topic-test-substance-exchange-and-digestion.md) - [3.3.5 A-A* (AO3/4) - Substance Ex & Digestion](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-3-5-a-a-ao34-substance-ex-and-digestion.md) - 3.4 Mass Transport - [3.4.1 Haemoglobin](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-1-haemoglobin.md) - [3.4.2 Oxygen Transport](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-2-oxygen-transport.md) - [3.4.3 The Circulatory System](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-3-the-circulatory-system.md) - [3.4.4 The Heart](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-4-the-heart.md) - [3.4.5 Blood Vessels](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-5-blood-vessels.md) - [3.4.6 Cardiovascular Disease](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-6-cardiovascular-disease.md) - [3.4.7 Heart Dissection](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-7-heart-dissection.md) - [3.4.8 Xylem](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-8-xylem.md) - [3.4.9 Phloem](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-9-phloem.md) - [3.4.10 Investigating Plant Transport](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-10-investigating-plant-transport.md) - [3.4.11 End of Topic Test - Mass Transport](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-11-end-of-topic-test-mass-transport.md) - [3.4.12 A-A* (AO3/4) - Mass Transport](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-12-a-a-ao34-mass-transport.md) - [3.4.13 Diagnostic Misconceptions - Concentration Gradient](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-13-diagnostic-misconceptions-concentration-gradient.md) - [3.4.14 Diagnostic Misconceptions - Cardiac Cycle](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-14-diagnostic-misconceptions-cardiac-cycle.md) - [3.4.15 Diagnostic Misconceptions - Carrying Capacity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-15-diagnostic-misconceptions-carrying-capacity.md) - [3.4.16 Diagnostic Misconceptions - Translocation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/3-4-16-diagnostic-misconceptions-translocation.md) ### 4 Genetic Information & Variation - 4.1 DNA, Genes & Chromosomes - [4.1.1 DNA](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-1-1-dna.md) - [4.1.2 Genes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-1-2-genes.md) - [4.1.3 Non-Coding Genes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-1-3-non-coding-genes.md) - [4.1.4 The Genetic Code](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-1-4-the-genetic-code.md) - [4.1.5 A-A* (AO3/4) - DNA](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-1-5-a-a-ao34-dna.md) - 4.2 DNA & Protein Synthesis - [4.2.1 Protein Synthesis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-2-1-protein-synthesis.md) - [4.2.2 Transcription & Translation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-2-2-transcription-and-translation.md) - [4.2.3 End of Topic Test - DNA, Genes & Protein Synthesis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-2-3-end-of-topic-test-dna-genes-and-protein-synthesis.md) - [4.2.4 Exam-Style Question - Protein Synthesis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-2-4-exam-style-question-protein-synthesis.md) - [4.2.5 A-A* (AO3/4) - Coronavirus Translation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-2-5-a-a-ao34-coronavirus-translation.md) - [4.2.6 A-A* (AO3/4) - Transcription](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-2-6-a-a-ao34-transcription.md) - [4.2.7 A-A* (AO3/4) - Translation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-2-7-a-a-ao34-translation.md) - 4.3 Mutations & Meiosis - [4.3.1 Mutations](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-3-1-mutations.md) - [4.3.2 Meiosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-3-2-meiosis.md) - [4.3.3 A-A* (AO3/4) - Meiosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-3-3-a-a-ao34-meiosis.md) - [4.3.4 Meiosis vs Mitosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-3-4-meiosis-vs-mitosis.md) - [4.3.5 End of Topic Test - Mutations, Meiosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-3-5-end-of-topic-test-mutations-meiosis.md) - [4.3.6 A-A* (AO3/4) - DNA,Genes, CellDiv & ProtSynth](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-3-6-a-a-ao34-dnagenes-celldiv-and-protsynth.md) - [4.3.7 Diagnostic Misconceptions - Meiosis vs Mitosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-3-7-diagnostic-misconceptions-meiosis-vs-mitosis.md) - 4.4 Genetic Diversity & Adaptation - [4.4.1 Genetic Diversity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-4-1-genetic-diversity.md) - [4.4.2 Natural Selection](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-4-2-natural-selection.md) - [4.4.3 A-A* (AO3/4) - Natural Selection](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-4-3-a-a-ao34-natural-selection.md) - [4.4.4 Adaptations](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-4-4-adaptations.md) - [4.4.5 Investigating Natural Selection](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-4-5-investigating-natural-selection.md) - [4.4.6 End of Topic Test - Genetic Diversity & Adaptation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-4-6-end-of-topic-test-genetic-diversity-and-adaptation.md) - [4.4.7 A-A* (AO3/4) - Genetic Diversity & Adaptation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-4-7-a-a-ao34-genetic-diversity-and-adaptation.md) - 4.5 Species & Taxonomy - [4.5.1 Courtship Behaviour](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-5-1-courtship-behaviour.md) - [4.5.2 Phylogeny](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-5-2-phylogeny.md) - [4.5.3 Classification](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-5-3-classification.md) - [4.5.4 DNA Technology](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-5-4-dna-technology.md) - [4.5.5 A-A* (AO3/4) - Species & Taxonomy](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-5-5-a-a-ao34-species-and-taxonomy.md) - 4.6 Biodiversity Within a Community - [4.6.1 Biodiversity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-6-1-biodiversity.md) - [4.6.2 Index of diversity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-6-2-index-of-diversity.md) - [4.6.3 Agriculture](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-6-3-agriculture.md) - [4.6.4 End of Topic Test - Species,Taxonomy& Biodiversity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-6-4-end-of-topic-test-speciestaxonomyand-biodiversity.md) - [4.6.5 A-A* (AO3/4) - Species,Taxon&Biodiversity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-6-5-a-a-ao34-speciestaxonandbiodiversity.md) - 4.7 Investigating Diversity - [4.7.1 Genetic Diversity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-7-1-genetic-diversity.md) - [4.7.2 Quantitative Investigation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/4-7-2-quantitative-investigation.md) ### 5 Energy Transfers (A2 only) - 5.1 Photosynthesis - [5.1.1 Overview of Photosynthesis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-1-overview-of-photosynthesis.md) - [5.1.2 Photoionisation of Chlorophyll](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-2-photoionisation-of-chlorophyll.md) - [5.1.3 Production of ATP & Reduced NADP](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-3-production-of-atp-and-reduced-nadp.md) - [5.1.4 Cyclic Photophosphorylation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-4-cyclic-photophosphorylation.md) - [5.1.5 Light-Independent Reaction](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-5-light-independent-reaction.md) - [5.1.6 A-A* (AO3/4) - Photosynthesis Reactions](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-6-a-a-ao34-photosynthesis-reactions.md) - [5.1.7 Limiting Factors](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-7-limiting-factors.md) - [5.1.8 Photosynthesis Experiments](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-8-photosynthesis-experiments.md) - [5.1.9 End of Topic Test - Photosynthesis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-9-end-of-topic-test-photosynthesis.md) - [5.1.10 A-A* (AO3/4) - Photosynthesis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-1-10-a-a-ao34-photosynthesis.md) - 5.2 Respiration - [5.2.1 Overview of Respiration](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-1-overview-of-respiration.md) - [5.2.2 Anaerobic Respiration](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-2-anaerobic-respiration.md) - [5.2.3 A-A* (AO3/4) - Anaerobic Respiration](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-3-a-a-ao34-anaerobic-respiration.md) - [5.2.4 The Link Reaction](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-4-the-link-reaction.md) - [5.2.5 The Krebs Cycle](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-5-the-krebs-cycle.md) - [5.2.6 Oxidative Phosphorylation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-6-oxidative-phosphorylation.md) - [5.2.7 Respiration Experiments](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-7-respiration-experiments.md) - [5.2.8 End of Topic Test - Respiration](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-8-end-of-topic-test-respiration.md) - [5.2.9 A-A* (AO3/4) - Respiration](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-9-a-a-ao34-respiration.md) - [5.2.10 Diagnostic Misconceptions - Aerobic vs Anaerobic](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-2-10-diagnostic-misconceptions-aerobic-vs-anaerobic.md) - 5.3 Energy & Ecosystems - [5.3.1 Biomass](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-3-1-biomass.md) - [5.3.2 Production & Productivity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-3-2-production-and-productivity.md) - [5.3.3 Agricultural Practices](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-3-3-agricultural-practices.md) - 5.4 Nutrient Cycles - [5.4.1 Nitrogen Cycle](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-4-1-nitrogen-cycle.md) - [5.4.2 Phosphorous Cycle](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-4-2-phosphorous-cycle.md) - [5.4.3 Fertilisers & Eutrophication](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-4-3-fertilisers-and-eutrophication.md) - [5.4.4 End of Topic Test - Nutrient Cycles](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-4-4-end-of-topic-test-nutrient-cycles.md) - [5.4.5 A-A* (AO3/4) - Energy,Ecosystems&NutrientCycles](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/5-4-5-a-a-ao34-energyecosystemsandnutrientcycles.md) ### 6 Responding to Change (A2 only) - 6.1 Nervous Communication - [6.1.1 Survival](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-1-survival.md) - [6.1.2 Plant Responses](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-2-plant-responses.md) - [6.1.3 Animal Responses](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-3-animal-responses.md) - [6.1.4 Reflexes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-4-reflexes.md) - [6.1.5 End of Topic Test - Reflexes, Responses & Survival](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-5-end-of-topic-test-reflexes-responses-and-survival.md) - [6.1.6 Receptors](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-6-receptors.md) - [6.1.7 The Human Retina](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-7-the-human-retina.md) - [6.1.8 Control of Heart Rate](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-8-control-of-heart-rate.md) - [6.1.9 End of Topic Test - Receptors, Retina & Heart Rate](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-1-9-end-of-topic-test-receptors-retina-and-heart-rate.md) - 6.2 Nervous Coordination - [6.2.1 Neurones](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-1-neurones.md) - [6.2.2 Action Potentials](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-2-action-potentials.md) - [6.2.3 Speed of Transmission](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-3-speed-of-transmission.md) - [6.2.4 End of Topic Test - Neurones & Action Potentials](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-4-end-of-topic-test-neurones-and-action-potentials.md) - [6.2.5 Synapses](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-5-synapses.md) - [6.2.6 Types of Synapse](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-6-types-of-synapse.md) - [6.2.7 Medical Application](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-7-medical-application.md) - [6.2.8 End of Topic Test - Synapses](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-8-end-of-topic-test-synapses.md) - [6.2.9 A-A* (AO3/4) - Nervous Comm&Coord](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-2-9-a-a-ao34-nervous-commandcoord.md) - 6.3 Muscle Contraction - [6.3.1 Skeletal Muscle](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-3-1-skeletal-muscle.md) - [6.3.2 Sliding Filament Theory](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-3-2-sliding-filament-theory.md) - [6.3.3 Contraction](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-3-3-contraction.md) - [6.3.4 Slow & Fast Twitch Fibres](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-3-4-slow-and-fast-twitch-fibres.md) - [6.3.5 End of Topic Test - Muscles](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-3-5-end-of-topic-test-muscles.md) - [6.3.6 A-A* (AO3/4) - Muscle Contraction](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-3-6-a-a-ao34-muscle-contraction.md) - 6.4 Homeostasis - [6.4.1 Overview of Homeostasis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-1-overview-of-homeostasis.md) - [6.4.2 Blood Glucose Concentration](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-2-blood-glucose-concentration.md) - [6.4.3 Controlling Blood Glucose Concentration](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-3-controlling-blood-glucose-concentration.md) - [6.4.4 End of Topic Test - Blood Glucose](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-4-end-of-topic-test-blood-glucose.md) - [6.4.5 Primary & Secondary Messengers](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-5-primary-and-secondary-messengers.md) - [6.4.6 Diabetes Mellitus](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-6-diabetes-mellitus.md) - [6.4.7 Measuring Glucose Concentration](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-7-measuring-glucose-concentration.md) - [6.4.8 Osmoregulation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-8-osmoregulation.md) - [6.4.9 Controlling Blood Water Potential](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-9-controlling-blood-water-potential.md) - [6.4.10 ADH](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-10-adh.md) - [6.4.11 End of Topic Test - Diabetes & Osmoregulation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-11-end-of-topic-test-diabetes-and-osmoregulation.md) - [6.4.12 A-A* (AO3/4) - Homeostasis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-12-a-a-ao34-homeostasis.md) - [6.4.13 Diagnostic Misconceptions - Effect of ADH](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/6-4-13-diagnostic-misconceptions-effect-of-adh.md) ### 7 Genetics & Ecosystems (A2 only) - 7.1 Genetics - [7.1.1 Key Terms in Genetics](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-1-key-terms-in-genetics.md) - [7.1.2 Inheritance](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-2-inheritance.md) - [7.1.3 Linkage](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-3-linkage.md) - [7.1.4 Multiple Alleles & Epistasis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-4-multiple-alleles-and-epistasis.md) - [7.1.5 Chi-Squared Test](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-5-chi-squared-test.md) - [7.1.6 End of Topic Test - Genetics](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-6-end-of-topic-test-genetics.md) - [7.1.7 A-A* (AO3/4) - Genetics](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-7-a-a-ao34-genetics.md) - [7.1.8 Diagnostic Misconceptions - Dihybrid Inheritance](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-8-diagnostic-misconceptions-dihybrid-inheritance.md) - [7.1.9 Diagnostic Misconceptions - Sex Linkage](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-1-9-diagnostic-misconceptions-sex-linkage.md) - 7.2 Populations - [7.2.1 Populations](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-2-1-populations.md) - [7.2.2 Hardy-Weinberg Principle](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-2-2-hardy-weinberg-principle.md) - 7.3 Evolution - [7.3.1 Variation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-1-variation.md) - [7.3.2 Natural Selection & Evolution](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-2-natural-selection-and-evolution.md) - [7.3.3 End of Topic Test - Populations & Evolution](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-3-end-of-topic-test-populations-and-evolution.md) - [7.3.4 Types of Selection](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-4-types-of-selection.md) - [7.3.5 Types of Selection Summary](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-5-types-of-selection-summary.md) - [7.3.6 Overview of Speciation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-6-overview-of-speciation.md) - [7.3.7 Causes of Speciation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-7-causes-of-speciation.md) - [7.3.8 Diversity](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-8-diversity.md) - [7.3.9 End of Topic Test - Selection & Speciation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-9-end-of-topic-test-selection-and-speciation.md) - [7.3.10 A-A* (AO3/4) - Populations & Evolution](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-10-a-a-ao34-populations-and-evolution.md) - [7.3.11 Diagnostic Misconceptions - Types of Speciation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-3-11-diagnostic-misconceptions-types-of-speciation.md) - 7.4 Populations in Ecosystems - [7.4.1 Overview of Ecosystems](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-1-overview-of-ecosystems.md) - [7.4.2 Niche](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-2-niche.md) - [7.4.3 Population Size](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-3-population-size.md) - [7.4.4 Investigating Population Size](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-4-investigating-population-size.md) - [7.4.5 End of Topic Test - Ecosystems & Population Size](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-5-end-of-topic-test-ecosystems-and-population-size.md) - [7.4.6 Succession](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-6-succession.md) - [7.4.7 Conservation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-7-conservation.md) - [7.4.8 End of Topic Test - Succession & Conservation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-8-end-of-topic-test-succession-and-conservation.md) - [7.4.9 A-A* (AO3/4) - Ecosystems](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/7-4-9-a-a-ao34-ecosystems.md) ### 8 The Control of Gene Expression (A2 only) - 8.1 Mutation - [8.1.1 Mutations](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-1-1-mutations.md) - [8.1.2 Effects of Mutations](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-1-2-effects-of-mutations.md) - [8.1.3 Causes of Mutations](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-1-3-causes-of-mutations.md) - [8.1.4 Diagnostic Misconceptions - Gene Expression](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-1-4-diagnostic-misconceptions-gene-expression.md) - 8.2 Gene Expression - [8.2.1 Stem Cells](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-1-stem-cells.md) - [8.2.2 Stem Cells in Disease](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-2-stem-cells-in-disease.md) - [8.2.3 End of Topic Test - Mutation & Gene Epression](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-3-end-of-topic-test-mutation-and-gene-epression.md) - [8.2.4 A-A* (AO3/4) - Mutation & Stem Cells](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-4-a-a-ao34-mutation-and-stem-cells.md) - [8.2.5 Regulating Transcription](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-5-regulating-transcription.md) - [8.2.6 Epigenetics](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-6-epigenetics.md) - [8.2.7 Epigenetics & Disease](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-7-epigenetics-and-disease.md) - [8.2.8 Regulating Translation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-8-regulating-translation.md) - [8.2.9 Experimental Data](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-9-experimental-data.md) - [8.2.10 End of Topic Test - Transcription & Translation](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-10-end-of-topic-test-transcription-and-translation.md) - [8.2.11 Tumours](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-11-tumours.md) - [8.2.12 Correlations & Causes](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-12-correlations-and-causes.md) - [8.2.13 Prevention & Treatment](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-13-prevention-and-treatment.md) - [8.2.14 End of Topic Test - Cancer](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-14-end-of-topic-test-cancer.md) - [8.2.15 A-A* (AO3/4) - Gene Expression & Cancer](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-2-15-a-a-ao34-gene-expression-and-cancer.md) - 8.3 Genome Projects - [8.3.1 Using Genome Projects](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-3-1-using-genome-projects.md) - 8.4 Gene Technology - [8.4.1 Recombinant DNA](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-1-recombinant-dna.md) - [8.4.2 Producing Fragments](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-2-producing-fragments.md) - [8.4.3 Amplification](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-3-amplification.md) - [8.4.4 End of Topic Test - Genome Project & Amplification](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-4-end-of-topic-test-genome-project-and-amplification.md) - [8.4.5 Using Recombinant DNA](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-5-using-recombinant-dna.md) - [8.4.6 Medical Diagnosis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-6-medical-diagnosis.md) - [8.4.7 Genetic Fingerprinting](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-7-genetic-fingerprinting.md) - [8.4.8 End of Topic Test - Gene Technologies](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-8-end-of-topic-test-gene-technologies.md) - [8.4.9 A-A* (AO3/4) - Gene Technology](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/8-4-9-a-a-ao34-gene-technology.md) ### 9 Mathematical Skills - 9.1 Mathematical Skills - [9.1.1 Diagnostic Misconceptions - Converting Units](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/9-1-1-diagnostic-misconceptions-converting-units.md) - [9.1.2 Diagnostic Misconceptions - Correct Hypothesis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/9-1-2-diagnostic-misconceptions-correct-hypothesis.md) - [9.1.3 Diagnostic Misconceptions - Interpret Hypothesis](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/9-1-3-diagnostic-misconceptions-interpret-hypothesis.md) - [9.1.4 Diagnostic Misconceptions - Calculate Uncertainty](https://senecalearning.com/en-gb/revision-notes/a-level/biology/aqa/9-1-4-diagnostic-misconceptions-calculate-uncertainty.md)