Consider statements about human circulation: 1. Arteries carry oxygenated blood. 2. Veins have valves to prevent backflow. 3. Capillaries have thick walls. Which are correct? MCQ with Answer and Explanation
Consider statements about human circulation: 1. Arteries carry oxygenated blood. 2. Veins have valves to prevent backflow. 3. Capillaries have thick walls. Which are correct?
A. 1 and 3 only
B. 1 and 2 only
C. 1, 2 and 3
D. 2 only
Answer: Option D
Solution (By JKSSB Mock Tests)
While most arteries carry oxygenated blood, the pulmonary artery carries deoxygenated blood from the heart to the lungs. Veins possess valves along their length to ensure unidirectional blood flow back to the heart against gravity. Capillaries are composed of a single layer of endothelial cells (thin walls) to facilitate the exchange of gases and nutrients. Only statement 2 is universally correct.
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