Q1. [1] straightforward initial-understanding
Why do veins have valves but arteries do not?
(a) Because arteries carry oxygenated blood.
(b) Because blood in veins is no longer under pressure and valves ensure one-directional flow.
(c) Because veins are thicker than arteries.
(d) Because arteries are closer to the heart.
- a Because arteries carry oxygenated blood.
- b Because blood in veins is no longer under pressure and valves ensure one-directional flow.
- c Because veins are thicker than arteries.
- d Because arteries are closer to the heart.