A student is investigating the process of osmosis. She fills a medicine dropper with red blood cells. Next, she creates a saline solution that is isotonic to the red blood cells. What will most likely happen to the red blood cells after they are placed in the solution?

Question

a
Water will neither enter or exit the cells and their sizes will remain the same.
b
Water will enter and exit the cells at a steady rate and their sizes will remain the same.
c
Water will enter the cells and cause them to grow in size.
d
Water will exit the cells and cause them to shrink in size.

Answer 1

The correct answer is:

b. Water will enter and exit the cells at a steady rate and their sizes will remain the same.

In an isotonic solution, the concentration of solutes outside the cell is equal to the concentration of solutes inside the cell. As a result, water moves in and out of the cells at equal rates, maintaining their size.