AQA GCSE Combined Science: Trilogy Biology Paper 1 (Higher), 2018: Question 2

✅ Correct answer

It is not caused by a pathogen / infectious organism and is not passed from person to person.

💡 Key knowledge

• Non-communicable means it cannot be caught or spread between people.
• It is not infectious or contagious.
• CHD is an example because it develops from fatty material building up in arteries, not from microbes.

🧠 Exam technique

• For 2 marks, give two separate points.
• One mark is for saying it is not caused by a pathogen.
• One mark is for saying it is not spread person to person.

❌ Common errors

• Saying only “it is not serious” — this does not answer the question.
• Saying “it is caused by poor lifestyle” — that may be true for some diseases, but it does not define non-communicable disease.
• Writing about infection, coughing, or germs will lose marks if you do not state the key idea clearly.

✅ Correct answer

Fatty material builds up in the coronary artery, so the artery becomes narrowed and blood flow is reduced or stopped. This means less oxygen reaches the heart muscle cells, so they cannot respire enough and do not release enough energy. This can lead to a heart attack.

💡 Key knowledge

• The coronary arteries supply the heart muscle with oxygenated blood.
• If the supply is reduced, heart muscle cells cannot carry out aerobic respiration
• Without enough oxygen, the heart muscle is damaged and may stop working properly.

🧠 Exam technique

• Use a chain of explanation: blockage → less blood flow → less oxygen → less respiration/energy → heart attack.
• You must mention the heart or heart muscle cells, not just “the body”.
• Short, linked sentences often score better than one long vague sentence.

❌ Common errors

• Talking only about a blood clot or blocked vessel without explaining the effect on oxygen.
• Saying “the heart stops breathing” — hearts do not breathe.
• Forgetting to say less oxygen reaches the heart muscle.

✅ Correct answer

CHD is more likely if a person has risk factors that cause fatty deposits to build up in the coronary arteries. For example, smoking damages blood vessels and is linked to high blood pressure and fatty deposition. A high fat / high energy diet, lack of exercise and obesity can increase cholesterol and blood pressure, which increases the chance of fatty material forming in arteries. Diabetes and genetic factors can also increase risk, because they can affect blood vessels, metabolism, blood pressure or cholesterol. Some medications can also affect blood or blood vessels, increasing risk.

💡 Key knowledge

• Lifestyle risk factors: smoking, obesity, lack of exercise, high fat / energy diet, insufficient fruit and vegetables, alcohol, high salt intake, air pollution, certain drugs.
• Medical risk factors: high blood pressure, high cholesterol, diabetes, genetic factors, medications.
• These factors often work by increasing blood pressure, cholesterol or fatty deposits in arteries.

🧠 Exam technique

• For level 3, you need both lifestyle and medical factors.
• Do not just list factors — explain how each one increases CHD risk.
• Best answers are logically linked, for example: smoking → high blood pressure → artery damage → fatty deposits .
• You can mention any correct examples, but linking them earns the top level.

❌ Common errors

• Only naming factors with no explanation.
• Confusing risk factors with direct causes.
• Writing about general illness without linking to coronary arteries, blood pressure, cholesterol or fatty deposition.
• Giving only lifestyle or only medical examples — the mark scheme says both are needed for top level.

💡 Examples of strong linked points

• Smoking → damages arteries / raises blood pressure → more likely to get fatty deposits.
• High salt intake → raises blood pressure → increases strain on arteries.
• Obesity / lack of exercise → can increase cholesterol / blood pressure / diabetes risk.
• High fat diet → raises cholesterol → more fatty material in arteries.
• Diabetes → affects blood vessels and increases CHD risk.
• Genetic factors → can cause high blood pressure or high cholesterol.

❌ Examiner insight: what lost marks

• Many students gave lists instead of explanations.
• Top answers clearly showed cause and effect.
• Students scored higher when they used both categories: lifestyle and medical.
• Marks were lost when “high blood pressure” or “cholesterol” were mentioned without saying why they matter.

✅ One-line answers to memorise

• Non-communicable disease = not caused by a pathogen and not spread person to person.
• CHD causes heart attack because narrowed coronary arteries reduce oxygen to the heart muscle.
• Risk factors increase CHD by raising blood pressure, cholesterol or fatty deposition.

🧠 Final exam tip

When a question says explain, always use because, so or therefore. That helps show the chain of reasoning the examiner is looking for.