Diffusion, Osmosis and Cell Membranes

Introduction

The red blood cells found in many animals are very important to the survival of the organism, because they transport oxygen from the gills, skin, or lungs to the cells of the various tissues (muscles, nerves, etc.). These blood cells are transported in a fluid (serum) that has approximately the same salt content as sea water. In this exercise, using what you have learned about diffusion and osmosis, you will design an experiment to test the effects of solutions of various concentrations on red blood cells.

Materials available

Microscope slides and cover slips, microscopes, blood, distilled water, physiological saline (similar to blood serum), salt, osmosis apparatus.

Method

Design an experiment using the above materials to determine the effects of solutions of various concentrations on red blood cells. To do this you must state your hypothesis, write the procedure, collect and record the data in an organized fashion, and report your conclusion, supported by evidence gained in the experiment and information you have gained from the previous exercises in this unit.

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