Part A: Osmosis practical task Aim: To observe the effects of osmosis in rhubarb cells. Hypothesis: Water will be extracted out of the cells in the salt solution causing the cells to look different to the cells in the freshwater solution. Materials: Rhubarb Distilled water in a dropping bottle Salt solution in a dropping bottle Microscope, slides, and coverslips Forceps and razor blades or scalpel Paper Towel Method: Clean and dry a slide and coverslip. Obtain a small sample of the red epidermal cells from the stalk of the rhubarb by carefully peeling away the layer with forceps. Prepare a wet mount slide of the rhubarb tissue in distilled water only. View your slide under low power on your microscope, and then switch to high power. Draw a diagram of the field of view, and label. Irrigate your slide with the salt solution. Leave for a few minutes. View one of your slides under low power on …show more content…
Additionally, it was difficult obtaining a piece of rhubarb that was thin and particularly red, therefore the effect could not be best observed in the cells. Part B: Design your own experiment Parts of this practical were taken and slightly altered from the following link http://www.markedbyteachers.com/gcse/science/investigate-the-effect-of-surface-area-on-osmosis-in-potato-tissue.html Aim: To observe the effect different surface area: volume ratios have on osmosis in potato tissue. Hypothesis: If the potato has a larger surface area: volume ratio, the quicker osmosis will take place and the larger the mass will be at the end of the experiment, therefore the difference in mass of the potatoes from the start of the experiment to the end of the experiment will be larger. Additionally, the potato pieces left in a saltwater solution will decrease in mass, whereas the pieces left in water will increase in mass. Materials and Equipment 2 Large potatoes Vegetable peeler Knife Chopping