This online simulated lab is an excellent substitute or supplement for the AP Biology Cell Unit Curriculum. This lab allows students to investigate with transport across permeable cell membranes. The lab is an easy to print/copy word document that utilizes one active link for a fair-use virtual website. The lab includes a detailed background section for the student, three objectives, and instructions on what the students should be learning in each simulated activity. The lab is extensive, investigating diffusion rate, passive movement and osmosis/dialysis. The lab includes data analysis, line graph construction and interpretation, labeled sketching of cells in various tonicities and 20 analysis questions. This is a fantastic alternative to the traditional College Board Osmosis and Diffusion lab. It could also be used in any college prep, honors biology or intro college-level course curriculum covering cell transport and the plasma membrane. The virtual lab investigation is easily completed in a 45 minute period. Additional classtime may be awarded for analysis and data interpretation (or this could be completed at home).