Q.) The exchange of material between the blood
and surrounding cells takes place through:
(a) Arteries (b) veins
(c) Capillaries (d) Nephrons
Ans: (c) Capillaries
Explanation: Capillaries are the smallest blood vessels that have walls which are one-cell thick. Exchange of material between the blood and surrounding cells takes place across this thin wall. Arteries are the vessels which carry blood away from the heart to various organs of the body. Veins collect the blood from different organs and bring it back to the heart.
