Question

A red blood cell placed in pure water would ________. Select one: a. shrink b. neither shrink nor swell c. swell initially, then shrink as equilibrium is reached d. swell and burst

Answer 1

Answer:

D (Swell and Burst)

Explanation:

Pure water contains a very low concentration of solute materials, hence it is regarded as HYPOTONIC. Since the red blood cell contains intracellular fluid that contains more solutes than the extracellular pure water it is placed in, it is said to be HYPERTONIC in comparison with the pure water.

This difference in concentration between the extracellular solution (pure water) and the intracellular fluid (red blood cell) called CONCENTRATION GRADIENT facilitates the movement of water by OSMOSIS. Osmosis is the process whereby water moves across a semi-permeable membrane from a region of low solute concentration to a high solute concentration.

Based on this osmotic gradient, water moves from the extracellular solution into the cell, causing it to swell and eventually burst as a result of excessive water intake.