So, it is not project based learning I know. Really I advocate project based learning, but many times Inquiry is as close as we can get.
In teaching cells, it is usually the same old drill. Compare plant and animal cells, make models, drill the cell parts, etc.
This time, we decided to just jump right in.
Students were asked one question: Are fruits and vegetables made of cells?
They then determined what they already knew about cells and what they needed to know/questions that they had. One of the questions was what is the best and easiest cell to obtain and what does it look like? We discussed how it is a good idea to have something to compare to and I offered some materials to provide background information. The two offerings were their own cheek cell and a red onion cell. Students asked about making parts stand out and we discussed two types of stains we would use. We also learned how to estimate size while looking under the microscope.
Students did a fabulous job. I was so impressed at what they learned including limitations of stains (for example, using iodine with potatoes causes the material to turn black because it is also an indicator and turns colors in the presence of starch.
Students created whatever format they could to answer the question and justify their answers with the evidence they collected throughout. Here is one such example: http://gottalovebio.wikispaces.com/GBPO#Are%20Fruits%20and%20Vegetables%20Made%20of%20Cells?