AQA GCSE Biology Biology Paper 1 (Foundation), November 2021: Question 5
14 marks · Standard Demand difficulty · Extended Answer
Explain the effects and treatments of coronary heart disease, interpret blood cholesterol data, and evaluate the use of anti-clotting drugs following a stent procedure.
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Question text
05 A high cholesterol concentration in the blood can lead to blockages inside arteries.
The coronary arteries supply blood to the heart muscle.
Figure 9 shows a coronary artery with a blockage.
Figure 9
05.1 Why could the blockage in Figure 9 cause cells in the heart to die?
[2 marks]
Doctors can measure the concentration of cholesterol in the blood.
Table 3 shows four different blood cholesterol categories.
Table 3
Blood cholesterol concentration
3 Cholesterol category
in mmol per dm
<4.6 Low
4.6–5.0 Normal
5.1–6.1 Medium
6.2 and above High
Figure 10 shows the blood cholesterol concentration of four people.
Figure 10
05.2 Which person is in the medium cholesterol category?
[1 mark]
Tick ( ) one box.
A B C D
05.3 Which person is most at risk of having a heart attack?
[1 mark]
Tick ( ) one box.
A B C D
05.4 Give a reason for your answer to Question 05.3.
[1 mark]
05.5 The blood cholesterol concentration of person D is greater than the blood cholesterol
concentration of person A.
Calculate how many times greater.
Use Figure 10.
[2 marks]
Number of times greater =
Figure 11 shows how a stent can be used to treat a person with a blockage in a
coronary artery.
Figure 11
05.6 Explain how a stent works as a treatment for a person with a blockage in a
coronary artery.
[2 marks]
Patients are given anti-clotting drugs after they have a stent fitted.
The drugs help to prevent clots forming in the blood.
05.7 Which part of the blood starts the blood clotting process?
[1 mark]
Tick ( ) one box.
Antibodies
Plasma
Platelets
Red blood cells 25
05.8 When a stent is fitted the doctor gives the patient an injection of anti-clotting drugs.
The patient then takes one anti-clotting tablet every day.
Anti-clotting drugs:
• are very effective
• can take a week to begin working fully
• have been used for over 60 years
• cost very little to make
• do not work effectively if the patient eats certain types of food.
The patient must have their blood tested every few weeks to check that the
anti-clotting drugs are working.
Evaluate the use of anti-clotting drugs in patients who have had a stent fitted.
[4 marks]
Mark scheme
Show the mark scheme
AO /
Question Answers Extra information Mark
Spec. Ref.
05.1 less blood flows through or less 1 AO1
blood flows to the heart (muscle 4.2.2.3
/ cells / tissue) 4.2.2.4
less oxygen (reaches the heart allow less respiration 1
muscle) allow less energy released
do not accept less energy
produced / made / created
05.2 D 1 AO3
4.2.2.4
05.3 B 1 AO3
4.2.2.4
05.4 is more likely to get a blockage ignore has the highest blood 1 AO2
(with high cholesterol) cholesterol concentration 4.2.2.4
or
blockage could be biggest
05.5 4 and 5.6 1 AO2
4.2.2.4
5.6 allow correct division using 1
� � = 1.4 either 5.3 or 5.8 (for person D)
05.6 opens / widens (artery) allow pushes blockage to the 1 AO1
side 4.2.2.4
so (more) blood can flow allow (more) oxygen(ated blood) 1
through can flow through
05.7 platelets 1 AO1
4.2.2.3
05.8 Level 2: A judgement, strongly linked and logically supported by a 3‒4 AO3
sufficient range of correct reasons, is given. 4.2.2.4
Level 1: Relevant points are made. They are not logically linked. 1‒2
No relevant content 0
Indicative content:
Advantages:
• only have to take the tablet once a day 13
• only a tablet so easy to take or only a tablet so not painful to
take
• (drugs are effective so) less likely to get a blood clot
• drugs are cheap so less cost to NHS or drugs are cheap so
(more) people can afford them
• drugs have been used for a long time so must be safe / trusted
Disadvantages:
• patients have to make sure they always have a supply of drugs
• patients could forget to take the drugs (every day)
• patients could still get a blood clot in the first week
• restrictions on lifestyle because patients have to have a blood
test every few weeks
• restrictions on lifestyle because patient can’t eat certain foods
• patients may get a blood clot if they eat the wrong food
• risks associated with puncturing skin / infection
• patient may have a fear of needles
• higher risk of bleeding / bruising
For Level 2 students must evaluate, including consideration of, the
advantage and disadvantage of anti-clotting drugs.
Total 14
How to answer it
Coronary Heart Disease, Stents and Drug Treatments
Core GCSE Biology Knowledge & Assessment Objectives:
- Coronary Heart Disease (CHD): How fatty blockages in coronary arteries lead to heart muscle damage and death via reduced blood flow and oxygen starvation.
- Graph & Data Skills: Reading discrete bar charts accurately, categorising risk using reference tables, and calculating relative scale factors ("times greater").
- Cardiovascular Treatments: How mechanical stents restore arterial lumen diameter and blood flow.
- Blood Components: Identifying the role of platelets in clot initiation.
- Extended Evaluation (4 Marks): Weighing advantages against disadvantages of anti-clotting drug therapy, leading to a supported conclusion.
Blockages in the Coronary Artery and Cell Death
Explain why a blockage in the coronary artery causes heart cells to die
✅ Mark Scheme Model Answer
- Mark 1: Less blood flows to the heart muscle / heart cells / tissue.
- Mark 2: Less oxygen reaches the heart muscle cells.
Alternative Mark 2: Allow "less glucose / less respiration / less energy released".
❌ Common Errors & Misconceptions
- "Energy is made / produced / created": Instant loss of mark! Energy is transferred or released by cellular respiration.
- Saying "no blood pumps around the body": The question asks specifically why cells in the heart die. Coronary arteries supply the heart muscle itself.
- Vague statements like "it stops working" without naming oxygen or blood flow.
Cholesterol Categories & Heart Attack Risk
Data reading and linking cholesterol concentration to risk
✅ Correct Responses
05.2 (1 Mark): Box D
05.3 (1 Mark): Box B
05.4 (1 Mark): Person B is most likely to get a blockage in their coronary arteries / the blockage could be the largest.
🧠 Exam Technique: Reading the Grid & Answering "Why"
- Reading Figure 10: Each small grid square on the y-axis = 0.2 mmol dm⁻³ . Person D sits at 5.6 mmol dm⁻³ , directly in the medium range (5.1–6.1).
- Watch out in 05.4: Do not just restate the question by saying "because B has the highest cholesterol". The mark scheme explicitly states: ignore 'has the highest blood cholesterol concentration'. You must give the biological consequence: high cholesterol causes fatty deposits/blockages in arteries.
Mathematical Calculation: Times Greater
Calculate how many times greater Person D's cholesterol is than Person A's
📐 Step-by-Step Calculation
- Step 1: Read values accurately from Figure 10:
Person A = 4.0 mmol dm⁻³
Person D = 5.6 mmol dm⁻³ (examiner allows 5.3 to 5.8)
[1 mark awarded for identifying both values] - Step 2: Calculate the ratio ("how many times greater"):
Divide the larger value by the base value:
5.6 ÷ 4.0 = 1.4
[1 mark awarded for correct answer]
Final Answer: 1.4 times greater
❌ Calculation Traps
- Subtracting instead of dividing: Calculating 5.6 - 4.0 = 1.6 calculates the difference, not how many times greater.
- Inverting the division: Dividing 4.0 ÷ 5.6 = 0.71 calculates the fraction of D that A represents.
Mechanical Action of a Stent
Explain how a stent works to treat a blockage in a coronary artery
✅ Mark Scheme Requirements
- Mark 1: It widens / opens the artery (or pushes the fatty blockage / plaque to the sides).
- Mark 2: So that more blood (or more oxygen / oxygenated blood) can flow through.
💡 Key Knowledge
A stent is a metal mesh tube inserted into a narrowed artery via a balloon catheter. When the balloon inflates, the wire mesh expands and locks in place, holding the arterial lumen open permanently.
Blood Components Recall
Which part of the blood starts the blood clotting process?
✅ Correct Answer
Platelets (small cell fragments without a nucleus suspended in plasma).
💡 Quick Recall of Other Blood Parts
- Red blood cells: Transport oxygen via haemoglobin.
- White blood cells & Antibodies: Defend against pathogens / infection.
- Plasma: Liquid medium transporting dissolved solutes (glucose, urea, CO₂).
Evaluation: Anti-Clotting Drugs Following Stent Surgery
Evaluate the use of anti-clotting drugs in patients who have had a stent fitted
🧠 How Examiners Mark Level 2 Responses (3–4 Marks)
To reach Level 2, you must present a balanced argument discussing both advantages and disadvantages, and finish with a clear, justified judgement / conclusion.
Advantages (Pick at least 2)
- Convenient routine: Only taken once a day as a tablet; non-invasive and painless.
- High efficacy: Very effective at preventing potentially fatal blood clots forming around the stent.
- Cost-effective: Cheap to produce, reducing the financial cost to the NHS and patients.
- Proven safety track record: Used for over 60 years, meaning long-term risks and interactions are well understood.
Disadvantages (Pick at least 2)
- Delay in action: Takes up to a week to become fully effective (requiring initial injections).
- Patient compliance risk: Patients must remember to take them every single day; missing doses increases clot risk.
- Dietary & lifestyle restrictions: Certain foods stop them working; frequent blood tests required (inconvenient, fear of needles, minor infection risk).
- Bleeding side effects: Increased risk of excessive bleeding, bruising, or internal haemorrhage.
📝 Model Level 2 Concluding Judgement
"Overall, despite requiring regular monitoring and dietary discipline, anti-clotting drugs are an essential and cost-effective treatment. The high efficacy in preventing life-threatening blood clots on the foreign surface of the stent far outweighs the minor inconvenience of daily tablets and blood tests."
Topics
Biology · B2: Organisation
Question and mark scheme from the AQA GCSE Biology examination, Biology Paper 1 (Foundation), November 2021. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.