Explain why the left ventricle has a thicker muscular wall than the right ventricle.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
The left ventricle pumps blood to the body (systemic circulation). The right ventricle pumps blood only to the lungs (pulmonary circulation). Because the systemic circulation requires a higher pressure to overcome the greater resistance of the body’s blood vessels, the left ventricle must generate greater pressure than the right ventricle. A thicker muscular wall in the left ventricle allows stronger contractions, producing the higher pressure needed for systemic circulation.
Examiner tips
- Use the exact terms ‘systemic circulation’ and ‘pulmonary circulation’.
- Show the logical link: higher resistance → higher pressure → thicker wall.
- Keep the answer concise – 4 points, one sentence each.
- Mention ‘muscular wall’ to match the mark scheme.”]
Mark scheme (4 marks)
- The left ventricle pumps blood to the body / all organs (systemic circulation)
- The right ventricle only pumps blood to the lungs (pulmonary circulation)
- The left ventricle must generate greater / higher pressure (than the right ventricle)
- A thicker muscular wall allows stronger contractions (to produce this higher pressure)
Key terms in this question
Related
- All Eduqas GCSE Biology revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →