AQA GCSE Physical Education Paper 1: The human body and movement in physical activity and sport, June 2025: Question 3

✅ Correct Answer

C – Stroke volume

💡 Key Knowledge

• Stroke Volume (SV): The amount of blood pumped out of the heart by each ventricle during one contraction/beat (measured in ml).
• Cardiac Output (Q): The total volume of blood ejected by the heart per minute (measured in litres/min).
• Heart Rate (HR): The number of times the heart beats per minute (bpm).
• Tidal Volume (TV): The volume of air inspired or expired in a normal breath (part of the respiratory system, not cardiovascular).

📐 How These Terms Connect

Remember the cardiac output equation:

Cardiac Output (Q) = Stroke Volume (SV) × Heart Rate (HR)

• SV: volume per beat (e.g. ~70 ml at rest)
• HR: beats per minute (e.g. ~70 bpm at rest)
• Q: volume per minute (e.g. 70 × 70 = ~4900 ml/min or 4.9 L/min)

🧠 Exam Technique

• Look for trigger words:
  • "one contraction" or "per beat" → Stroke volume
  • "per minute" → Cardiac output
  • "air" or "breath" → Tidal volume
• Rule out wrong systems: "Tidal volume" relates to the lungs and breathing mechanics, so it can be eliminated instantly for questions asking about the heart and blood.

❌ Common Errors

• Confusing Stroke Volume with Cardiac Output: This is the most common mistake. Students see "amount of blood pumped" and rush to choose Cardiac Output without checking the time frame (one contraction vs one minute).
• Mixing up Respiratory and Cardiac terms: Confusing Stroke volume (blood per beat) with Tidal volume (air per breath) simply because both contain the word "volume".