Yogurt bacteria lab to check out bacteria that is in yogurt. I found this year that lactose free yogurt had more bacteria. It helps to leave the yogurt out for an hour or more before having the students observe it.
Prokaryotic and eukaryotic cell comparisons can be done with any slide samples. I covered the name of the sample and numbered the slides instead. Students worked in pairs with a set of 4 slides. They drew all four slide and then compared them with what they know about prokaryotic and eukaryotic cells. They then had to choose which samples matched the type of cells. I had a challenge set for students who seemed ready as well.