Explain why the heart is described as having two separate sides, and outline why this arrangement is important for supplying oxygen to the body's tissues.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
The heart has two separate sides because the right side pumps de‑oxygenated blood to the lungs, while the left side pumps oxygenated blood to the rest of the body.
Keeping the two types of blood separate prevents mixing of oxygenated and de‑oxygenated blood.
This separation ensures that the blood delivered to tissues has a high oxygen concentration, allowing efficient oxygen delivery to the body’s cells.
Keeping the two types of blood separate prevents mixing of oxygenated and de‑oxygenated blood.
This separation ensures that the blood delivered to tissues has a high oxygen concentration, allowing efficient oxygen delivery to the body’s cells.
Examiner tips
- Use the exact terms ‘right side’ and ‘left side’ and state the functions of each. Mention ‘de‑oxygenated’ and ‘oxygenated’ blood. Explain the importance of keeping them separate. Keep the answer short and to the point.
Common mistakes
- Confusing the functions of the right and left sides, or saying both sides pump the same blood. Forgetting to mention that separation prevents mixing of oxygenated and de‑oxygenated blood. Using vague language such as ‘good for the body’ instead of specifying oxygen delivery.
Mark scheme (4 marks)
- The right side of the heart pumps deoxygenated blood to the lungs
- The left side of the heart pumps oxygenated blood to the rest of the body
- Keeping oxygenated and deoxygenated blood separate prevents mixing
- This ensures tissues receive blood with a high oxygen concentration / efficient delivery of oxygen to tissues
Key terms in this question
Related
- All WJEC GCSE Biology (Wales) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →