Lesson 3: What are microbes?

This lesson defines the term “microbe” and introduces students to the diversity of microbes. Students first watch an engaging video that reviews some elements of the previous lessons about the place of microbes in the tree of life while making connections to what is to come as the unit continues to explore the different roles and ubiquity of microbes. The second activity scaffolds students’ concept of scale as they work with units and conversions to become more familiar with the microscopic scale. This concept of scale is then applied in the third activity where students make a “microbe mural”. To create the mural, students produce scaled up versions of different microbes and discuss aspects of microbial diversity such as their size, where they live, and their metabolic properties.