AQA AS Level Biology Paper 2, June 2022: Question 6
8 marks · Medium difficulty · Practical Techniques & Data Analysis
Evaluate the effect of blood pressure treatments on reducing cardiovascular disease risk using data from provided graphs on heart blood volume, blood pressure correlation, and treatment changes.
Practise this questionQuestion
Question text
06.1 A student dissected a sheep’s heart. He prepared a risk assessment on:
• carrying a scalpel
• using a scalpel.
Complete Table 3 by giving three control measures the student must use to reduce
the risks associated with carrying and using a scalpel.
Table 3
Source Hazard Control measures to reduce risk
1.
2.
Sharp
knife
3.
[2 marks]
06.2 A scientist measured the changes in blood volume inside the left ventricle of a
mammalian heart during one heartbeat. Figure 5 shows her results.
Figure 5
Use Figure 5 to calculate the total volume of blood pumped from the left ventricle
in 1 minute.
[2 marks]
Answer cm3
Scientists investigated the correlation between patients’ blood pressure (bp) and the
risk of these patients developing cardiovascular disease.
*17* They grouped the blood pressure measurements into four health categories: low,
ideal, pre-high and high blood pressure.
Figure 6 shows the scientists’ results.
Figure 6
In a separate investigation, a doctor measured the effect of blood pressure medicines
on treating a large number of patients with a mean blood pressure of 22 kPa
The doctor used two different treatments.
• Treatment 1 contained one blood pressure medicine.
• Treatment 2 contained three blood pressure medicines.
He measured the change in the mean blood pressure after each treatment in these19
patients.
Figure 7 shows his results.
Figure 7
06.3 Using information in Figure 6 and Figure 7, evaluate the effect of these treatments on
reducing the risk of developing cardiovascular disease in patients with a mean blood
pressure of 22 kPa
[4 marks]
Mark scheme
Show the mark scheme
Question Marking Guidance Mark Comments
Accept for 2 marks, three correct responses, one More than one correct
of which MUST be MP1. answer can be given
in each cell row
Accept for 1 mark, any two correct responses.
Ignore wear safety
glasses OR gloves
1. Carry with blade protected
Ignore ‘no running’
OR Ignore washing OR
disinfecting
Do not carry if likely to be jostled; hands/surfaces
2. Cut away from body; Ignore taking care OR
act safely OR keep
3. Cut onto hard surface; 2
06.1 away from fingers
4. Use sharp blade; (2 x AO1)
1. Accept for
5. Disinfect/dispose of used scalpel (blade) as ‘protected’, e.g. in
instructed; tray OR pointing
down
3. Accept for ‘hard
surface’, e.g. board
OR tile. Ignore ‘flat’
5. Accept for ‘as
instructed’, e.g. in
tray/beaker/as
directed (by
teacher)
Accept for 2 marks, 6150;;
Accept for 1 mark,
82 (correct blood volume pumped in one
heartbeat)
OR
Evidence of 120 and 38 (correct readings from 2
06.2 graph)
(2 x AO2)
OR
75 (correct heart rate, bpm)
OR
e.c.f. from graph, e.g. 120 – 40 = 80 and
80 × 75 = 6000;
1. Treatment 2 reduces bp/risk more (than
treatment 1) 13
OR
Treatment 2 is more effective (than treatment
1)
2. Neither treatment achieves ideal bp
OR
Neither treatment achieves low(est) risk;
3. With treatment 1, patients (still) have high bp/
20.3 bp so (still) at high risk
4 max
06.3
4. With treatment 2, patients in pre-high bp/18 bp (4 x AO3)
so (still) at higher risk than normal;
5. No statistics test so do not know if 5. Reject ‘results are
changes/differences (in bp) are significant significant’
OR
No statistics test so do not know if
changes/differences (in bp) are due to chance;
6. Unknown side effects of treatment(s);
7. Unknown duration of treatments;
8. Large sample size so results representative;
How to answer it
AQA AS Level Biology Study Guide: Mammalian Heart Dissection & Cardiovascular Risk
This question assesses practical safety procedures during biological dissections (AO1), interpreting graphical cardiac cycle data to perform multi-step mathematical calculations with units (AO2), and evaluating scientific data linking treatments, blood pressure, and disease risk while identifying methodological limitations like statistics and side effects (AO3).
Question 06.1: Dissection Risk Assessment
Complete Table 3 with three control measures for carrying and using a scalpel. (2 marks)
✅ Correct Answers (Any 3)
- Carry with the blade protected (e.g., in a tray or pointing down) - Mandatory for 2-mark answers.
- Do not carry if likely to be jostled.
- Cut away from the body.
- Cut onto a hard surface (e.g., dissection board).
- Use a sharp blade (blunt blades slip more easily).
- Disinfect or dispose of used scalpel blades safely as instructed.
❌ Common Errors & Examiner Traps
- Vague safety rules: Writing "wear safety glasses" or "wear gloves" is ignored because gloves do not protect against deep scalpel cuts.
- Behavioural statements: Writing "no running" or "take care" are too generic and not specific laboratory control measures for sharp instruments.
- Missing the mandatory point: To achieve full 2 marks, at least one point *must* relate directly to carrying the scalpel safely.
Question 06.2: Cardiac Cycle Calculation
Use Figure 5 to calculate the total volume of blood pumped from the left ventricle in 1 minute. (2 marks)
📐 Step-by-Step Calculation
- Find stroke volume (volume per heartbeat): Max volume (approx 120 cm³) minus Min volume at end of ventricular systole (approx 38 or 40 cm³).
120 - 40 = 80 cm³ (or 120 - 38 = 82 cm³ ). - Find heart rate (beats per minute): Total duration of one cycle on the x-axis is 0.8 s.
60 seconds / 0.8 seconds = 75 beats per minute . - Calculate total cardiac output per minute: Stroke Volume × Heart Rate.
80 cm³ × 75 bpm = 6000 cm³ (or using 82: 82 × 75 = 6150 cm³ ).
🧠 Exam Technique & ECF
- Error Carried Forward (ECF): If you misread the minimum volume as 40 cm³, your stroke volume is 80 cm³. Multiplying by 75 gives 6000 , which still receives credit!
- Check your graph scales: Always carefully count grid squares to establish minor axis values before reading values off axes.
Question 06.3: Evaluating Treatments & Risk
Using information in Figure 6 and Figure 7, evaluate the effect of these treatments on reducing the risk of developing cardiovascular disease in patients with a mean blood pressure of 22 kPa. (4 marks max)
💡 Key Knowledge Points (Mark Scheme Accepted Points)
- Treatment comparison: Treatment 2 reduces blood pressure and disease risk more than Treatment 1 (drops bp by 4 kPa vs 1.7 kPa).
- Target achievement: Neither treatment achieves an "ideal" blood pressure (below 16 kPa) or reaches the lowest risk category.
- Residual risk (Treatment 1): After Treatment 1 (drop of 1.7 kPa from 22 kPa leaves 20.3 kPa), patients still have high blood pressure and remain at high risk.
- Residual risk (Treatment 2): After Treatment 2 (drop of 4 kPa from 22 kPa leaves 18 kPa), patients are in the pre-high blood pressure category, so risk is lower than Treatment 1, but still higher than normal.
- Methodological limitations: No statistical test was carried out, so we cannot know if differences or changes are significant or due to chance. Side effects and long-term duration are unknown.
🧠 Top-Level Response Strategy
- Combine both figures: To score high marks, you must link the blood pressure drop shown in Figure 7 back to the risk curve shown in Figure 6.
- Use quantitative data: Quote specific numbers from the graphs (e.g., initial 22 kPa, drops of 1.7 kPa and 4 kPa) to back up your evaluation statements.
- Avoid sweeping statements: Do not say "results are significant" without statistical tests; instead, discuss whether differences are reliable.
Topics
Biology · Practical skills · Required Practicals · 3.3 Organisms exchange substances with their environment · Experimental design · Data analysis · AS practicals (1–6)
Question and mark scheme from the AQA AS Level Biology examination, Paper 2, June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.