AQA GCSE Biology Biology Paper 1 (Foundation), June 2024: Question 7

✅ Correct Answer

Arteries (specifically the coronary arteries that supply blood to the heart muscle).

💡 Key Knowledge

Coronary heart disease occurs when layers of fatty deposits build up inside the coronary arteries, narrowing them and restricting blood flow to the heart muscle cells.

✅ Correct Answers

07.2 Compressions (2 marks):

• [Mark 1] Pushes / moves blood (mechanically pumping it).
• [Mark 2] To get oxygen around the body (or to vital organs like the brain).

07.3 Rescue Breaths (1 mark):

• Provides oxygen (for aerobic cellular respiration) OR provides CO₂ to trigger breathing reflexes.

❌ Common Misconceptions

• "Compressions restart the heart": Pushing on the chest does not restart an electrical rhythm; that requires a defibrillator. Compressions merely act as a temporary mechanical pump.
• "Moves oxygen to the lungs": Oxygen travels from the lungs to the body, not the other way around. Saying it pumps blood to the lungs to pick up oxygen does not earn Mark 2 unless body delivery is stated.

✅ Correct Answers

07.4 Cholesterol-lowering drug (1 mark):

Statin(s) (or a specific named statin like atorvastatin).

07.5 How a stent works (2 marks):

• [Mark 1] Opens / widens / holds open the blocked or narrowed blood vessel.
• [Mark 2] To allow more blood to flow (or deliver more oxygen/glucose to the heart muscle cells).

🧠 Exam Technique: Two-Part Answers

Questions asking "how something works" usually award:

1. Physical mechanism: What the device actually does to the anatomy (expands the lumen of the artery).
2. Biological effect: What consequence this has (restores oxygen and glucose supply for respiration in the heart muscle).

❌ Common Errors

• Do not say "unblocks" or "melts fat": Stents are metal mesh tubes. They compress fatty plaques against the wall; they do not remove, dissolve, or digest the plaque.
• Spelling: Confusing statins with stems or stents will lose the mark for 07.4.

✅ Mark Scheme Valid Conclusions (Any Two)

• Smoking increases the percentage risk of all types of cardiovascular disease tested.
• Smoking increases the risk of Disease H the most (or patients who smoke are most likely to develop H).
• Smoking increases the risk of Disease E the least.
• A specific comparative conclusion (e.g. "Smoking increases the risk of H more than triple the risk of F").

❌ Where Marks Were Lost

• "Smoking causes cardiovascular disease": Too vague! The table gives percentage increases in risk; it shows an association/increased risk, not absolute proof of causation in this single dataset.
• Quoting raw numbers without drawing a conclusion: Simply copying "E is 14% and H is 70%" is reading data, not making a conclusion. You must use words like most, least, or compare them directly.

📐 Step-by-Step Graph Construction

1. Y-axis Label (1 mark): Write out the full header from Table 5:
   Percentage (%) increase in risk (compared to people who have never smoked) .
2. Linear Scale (1 mark): The y-axis must have regular increments. Use 1 cm (1 major grid box) = 5% or 2 cm = 10%. It must reach at least 70% and start at 0.
3. Plotting Bars (1 mark):
   • F: Height = 20%
   • G: Height = 29% (just under the 30% line)
   • H: Height = 70%
   • Tolerance: Must be accurate to within ±½ of a small grid square.
4. Labelling Bars (1 mark): Clearly label each bar underneath as E, F, G, and H.

🧠 Top Tips for Full Marks

• Match bar widths: Keep your drawn bars (F, G, H) the exact same width as the pre-drawn bar E.
• Leave neat gaps: Since this is discrete categorical data (different named diseases), leave equal spaces between bars.
• Use a sharp pencil and ruler: Wobbling, freehand lines or blunt pencils frequently lead to losing the accuracy mark.

✅ Acceptable Answers (Choose ONE)

• Poor diet: High saturated fat, high cholesterol, or high salt intake.
• Lack of exercise / sedentary lifestyle.
• High alcohol consumption.
• Prolonged stress (e.g. high-stress occupation).

❌ Common Pitfalls

• Do NOT write "Smoking": The question specifically commands: "Do not refer to smoking in your answer."
• Avoid writing "Obesity" alone: Obesity is a physiological condition/medical risk factor caused by lifestyle choices, not the lifestyle behaviour itself. The mark scheme explicitly states: "ignore obesity".
• Avoid unqualified "Diet": Stating just "diet" is insufficient; you must state poor diet or specify high in fat/salt.