CIE iGCSE Co-Ordinated Science B9.2 Heart Exam Style Questions Paper 1
▶️ Answer/Explanation
The left ventricle has the most muscular wall of all four heart chambers. This is because it must generate a much higher pressure to pump oxygenated blood through the aorta and around the entire body via the systemic circulation. The distance and resistance in the systemic circuit are much greater than in the pulmonary circuit.
The right ventricle only pumps deoxygenated blood to the lungs (pulmonary circulation), which is a shorter distance and at lower resistance, so its muscular wall is thinner. The atria only pump blood into the ventricles, so they have the thinnest walls.
✅ Answer: (B)
▶️ Answer/Explanation
Smoking tobacco is a known risk factor for coronary heart disease as it damages the lining of arteries and contributes to the build-up of fatty deposits (atheroma) that can block the coronary arteries. A reduced salt diet, relaxation therapy, and regular exercise are all lifestyle choices that help reduce the risk of heart disease rather than increase it.
✅ Answer: (D)
✅ Answer: (D)
▶️ Answer/Explanation
Coronary heart disease occurs when the coronary arteries become narrowed or blocked due to a build-up of fatty deposits (atherosclerosis). This restricts blood flow to the heart muscle, reducing oxygen supply and potentially leading to a heart attack. The blockage, not enlargement of arteries or heart muscles, is the direct cause.
✅ Answer: (A)
✅ Answer: (A)
▶️ Answer/Explanation
The aorta is the largest artery in the body, carrying oxygenated blood away from the left ventricle to the rest of the body.
Blood flow in the aorta is directed away from the heart, making it an artery carrying blood from the heart to the body.
✅ Answer: (A)
Blood flow in the aorta is directed away from the heart, making it an artery carrying blood from the heart to the body.
✅ Answer: (A)