This is a great activity to include in a microbiology or taxonomy unit! In this activity students will use a dichotomous key to identify bacteria based on four characteristics: Gram stain, cell shape, arrangement, and motility. The activity features 12 species of medically important bacteria. The answer key is included.
Implementation: First, I review the four characteristics for identifying bacteria as a whole class. Then, I go over the example and allow students work in pairs to identify the bacteria. Afterwards, I have them paste their data tables into their interactive notebooks.