AP Bio Paper

• How does Milk of Magnesia® work?

Each student will write a one-page paper answering their assigned question and its relationship to diffusion, osmosis, and water potential. 

Part 2: 

You will now use a real-life example of osmosis and diffusion in action. The presence of the anthocyanin pigment in the epidermal cells contributes to a good visual illustration of osmosis.

Watch the following video showing red onion cells beginning in an isotonic solution: https://www.youtube.com/watch?v=mXKqYrlmeMs

During the first minute of the video, salt water is introduced. After minute one, distilled water is added to the cells. Note what is happening to the cell membrane, cell wall, and large central vacuole (containing the pigment). 

In 1-2 paragraphs, write an explanation of cellular changes from beginning to end of the video as it relates to diffusion, osmosis, and water potential. 

In addition, please use Google Draw or draw your own picture (with color) showing what is occurring in the video. Three diagrams are sufficient (ex. Cell in isotonic solution, cell in salt water, cell in distilled water). Include arrows and labels on your diagram.