Question

the concentration of solutes in a red blood cell is about 2%. sucrose cannot pass through the membrane, but water and urea can. osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions? pure water a hypertonic urea solution a hypertonic sucrose solution a hypotonic urea solution a hypotonic sucrose solution

Explanation:

Step1: Understand osmosis principle

Osmosis is the movement of water across a semi - permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Step2: Analyze cell shrinkage

Red blood cells shrink when water moves out of them. This occurs in a hypertonic solution (higher solute concentration outside the cell compared to inside).

Step3: Evaluate options

• Pure water is hypotonic to red blood cells, water would move in and cells would swell, not shrink.
• Hypotonic solutions (urea or sucrose) have lower solute concentration than red blood cells, water would move in.
• Urea can pass through the membrane, so a hypertonic urea solution may not cause as significant a water - out movement as a non - permeating solute like sucrose. A hypertonic sucrose solution (where sucrose cannot cross the membrane) will cause the most water to move out of the red blood cells, leading to the most shrinkage.

Answer:

C. a hypertonic sucrose solution