1. Label the heart with: left atrium, right atrium, left ventricle, right ventricle, aorta, pulmonary artery, pulmonary vein, vena cava. [8]
[Heart diagram]
Mark Scheme
1. All eight labels correct [8]
2. Valves prevent backflow and keep blood moving in one direction [2]
3. Blood passes through the heart twice per circuit: pulmonary and systemic circulation [3]