10+ Year Member
Nov 2, 2008
I'm having trouble with the wording on this question. Please help me out!

11. A sample of blood is added to a test tube containing a 1.6% salt solution. A short while later, the red blood cells are observed to be smaller and wrinkled in shape due to water loss. This indicates that

A. red blood cells are isotonic to the 1.6% salt solution
B. red blood cells are hypertonic to the 1.6% salt solution
C. red blood cells are hypotonic to the 1.6% salt solution
D. the 1.6% salt solution is hypotonic to the red blood cells
E. the 1.6% salt solution is isotonic to the red blood cells

The answer is C.

However, I chose B as my answer because in a hypertonic environment, water bursts out of the RBC, causing it to wrinkle. Am I getting mixed up on the wording? :confused:

Apr 15, 2009
Boston, MA
If the rbcs were hypertonic it would cause the solution to flow into them causing them to swell and possibly lyse. In B, the answer you choose, the environment would be hypotonic not hypertonic. In C, if the RBCs are hypotonic then the solution that they are in would be hypertonic causing them to shrivel.