Question

Red blood cells have a tonicity of 0.9%. If a red blood cell is placed in a 3% saline solution the cell would _______________.

Answer 1

Red blood cells have tonicity of 0.9%. If a red blood cell is placed in a 3% saline solution the cell will shrink.

Its because 3% saline is a hypertonic solution(tonicity is greater than RBC) then the intracellular water will rush to the outside of the cell, it causes shrinkage of the cell.

In the case of a Hypotonic solution, the water will rush inside the cell, that will cause swelling.

And, in case of isotonic solution(The tonicity is same) then the RBC will remain same and intact.