Osmosis causes water to move from areas of low salt concentration to areas of high salt concentration.
The internal NaCl concentration of red blood cells is 0.9 M. The diagram below shows red blood cells submerged in solutions of four different NaCl concentrations—0 M, 0.65 M, 0.9 M, and 2 M.
red blood cell osmosis
Which of the diagrams shows red blood cells in the 2 M solution?
A.
4
B.
1
C.
2
D.
3
D. 3
To determine which diagram shows red blood cells in the 2 M solution, we need to understand how osmosis works. Osmosis is the movement of water from an area of lower solute concentration (in this case, lower salt concentration) to an area of higher solute concentration (higher salt concentration) through a semi-permeable membrane.
In this scenario, the internal salt concentration of red blood cells is 0.9 M. Therefore, we are looking for the diagram that depicts a solution with a higher salt concentration than 0.9 M.
By analyzing the options:
- Diagram 1 shows red blood cells in a solution with 0 M salt concentration, which is lower than 0.9 M. Thus, it does not represent the 2 M solution.
- Diagram 2 shows red blood cells in a solution with 0.65 M salt concentration, which is still lower than 0.9 M. Therefore, it does not represent the 2 M solution.
- Diagram 3 shows red blood cells submerged in a solution with 0.9 M salt concentration, which is the same as the internal concentration of red blood cells. This solution does not represent the 2 M solution.
- Diagram 4 shows red blood cells in a solution with 2 M salt concentration, which is higher than 0.9 M. Hence, this is the correct diagram that represents red blood cells in the 2 M solution.
Therefore, the answer is option A, Diagram 4.