Notes to Instructors M05_REEC5174_09_IE_27_40.VERIFIED

What is the focus of these activities? Activity 27.1 How diverse are the Archaea? Relatively recent studies indicate that prokaryotes are incredibly diverse, so diverse that they have been split into two domains: the Archaea and the Eubacteria. This activity helps students see that it is likely that early lifeforms were more similar to the Archaea. In other words, life on the early Earth was very different from what we see today. Activity 27.2 How has small size affected prokaryotic diversity? This activity is designed to help students understand how small size has limited morphological diversity but promoted biochemical (metabolic) diversity among the prokaryotes. What misconceptions or difficulties can these activities reveal? Activity 27.2 We often state that the prokaryotes are more diverse metabolically and the eukaryotes are more diverse morphologically. Then we go on to indicate that a wide variety of metabolic types exist in the prokaryotes. As instructors, we understand that any single species of prokaryote has a specific type of metabolism. When we talk about the variety of metabolic types, we mean that different species of prokaryotes can display very different types of metabolism. Some students don’t have this same understanding, however. They