Eastern Regional High School
Biology
Name:__________________________________
Mod:__________ Date:___________________
Unit 7 – The Plasma Membrane
Worksheet – Osmosis in Living Cells
1. Identify the tonicity of the following cells and the surrounding solutions then draw an arrow that
shows the net movement of water.
Beaker
Salt 40%
Water
60%
Cell
Salt 90%
Water
10%
A. Cell- ____Hypotonic____
Solution - ____Hypertonic______
Beaker
Salt 27.5%
Water
72.5%
Cell
B. Cell- _____Hypotonic____
Solution - ____Hypertonic_____
1
Salt 29.3%
Water
70.7%
Beaker
Salt 45%
Water
55%
Salt 45%
Water
55%
Cell
C. Cell- ____Isotonic____
Solution - _____Isotonic______
Beaker
Salt
23.5%
Salt
23.9%
Cell
D. Cell- _____Hypertonic_____
Solution - _____Hypotonic______
2
2. A cell contains 68% water, 2% salt, and 30% other solutes. The solution it is found in contains
70% water, 3% salt, and 27% other solutes:
a. The solution in this example is hypo, hyper or isotonic? _____Hypotonic______
b. Sketch a diagram in the box below that illustrates the situation in this problem: Include
arrows that show the movement of water molecules.
Beaker
Hypo
70%
68%
3. A cell contains 78% water, 2% salt, and 20% other solutes. The solution it is found in contains
75% water, 3% salt, and 22% other solutes:
a. The solution in this example is hypo, hyper or isotonic? ______Hypertonic_____
b. Sketch a diagram in the box below that illustrates the situation in this problem: Include
arrows that show the movement of water molecules.
Beaker
78%
3
75%