Biol 211 Lab 3
PreLab Discussion
Part I Demonstration of diffusion and Osmosis
Inside the dialysis slide is water and starch. Outside the slide is water and iodine.
In dialysis molecules always move from an area of high concentration to an area of low concentration
(if they can!)
Which way will starch move?
Which way will iodine move?
Which way will the water move?
Where will the color appear?
Part 2: The “Egg Lab”: Determining the Relative Concentration of Two Solutions by Osmosis
In the post lab you are asked to plot your data.
Which axis will be the independent (X) variable?
Which axis will be the dependent (Y) variable?
What units will you use?
Part 3: Plasmolysis -- Observing Osmosis in a Living System
Based on the description of what will happen to the plant leaf, is the salt solution hypotonic, isotonic or
hypertonic compared to the plant cell?