The arteries are thick-walled and elastic, while the veins have valves. Which is the best explanation of this difference?
Answer and explanation
Correct answer: B. Arteries carry blood at high pressure, veins at low pressure
- Step 1: Structure matches function.
- Step 2: High pressure needs strong elastic walls; low pressure requires valves to stop backflow.
Answer
Arteries carry blood at high pressure, veins at low pressure.
Why not the others: Arteries carry blood at low pressure and veins at high pressure: they carry it at high pressure. Veins carry oxygenated blood to the lungs: the pulmonary vein carries oxygenated blood to the heart, and this does not explain valves. Arteries absorb nutrients from the blood into tissues: capillaries exchange materials.
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