Topics: Biology Cells Eukaryotic Prokaryotic Science
Grade Level: University
Context: in classroom content delivery
Overview: This lesson is at the beginning of a unit on cells and prepares students for a subsequent laboratory exercise designed to help them differentiate cells.
Learning Objectives: To be able to compare and contrast prokaryotic and eukaryotic cells
- 1. Students are shown electron micrographs of 2 cells: one prokaryotic and one eukaryotic. They are asked to look for similarities and differences.
2. InkSurvey Question: Make a Venn diagram to show the similarities and differences you observed between these 2 cells. 3. Summarize for the class some of the observations reported in InkSurvey 4. Lecture on roots of words; lecture on fundamental differences between these 2 groups, using same 2 cells for illustration. 5. Show additional micrographs of cells and discuss how they illustrate prokaryotic vs. eukaryotic 6. Repeat the same InkSurvey Question: Make a Venn diagram to show the similarities and differences you observed between these 2 cells. 7. Use the "sort" feature to select some student responses to project for class discussion to further refine student understanding and correct misconceptions. Emphasize what is important to a biologist.
- Students immediately perform a laboratory exercise using light microscopes to observe the similarities and differences between these cell types.
What student misconceptions were revealed by the formative assessment and how did you address them?
- There was considerable improvement between the first and second iterations of the formative assessment question. After the lecture on this topic, most students in the second round were able to list "a true, membrane-bound nucleus" as the defining trait of eukaryotes (success!), but they also listed some "false" differences as well (for example, several thought that only prokaryotes have cell walls, even though cell walls hadn't even been discussed). I was also surprised how much trouble the students had in coming up with similarities of these 2 types of cells. Many left the overlap area on the Venn diagram blank, or filled it with incorrect structures such as mitochondria. They didn't think of obvious common structures such as cytoplasm and the plasma membrane. I reinforced correct understandings and repaired misconceptions by selecting 5 student responses to display anonymously to the class and opened it to discussion. This seemed to be a necessary step for some students to master this learning objective.
After receiving the InkSurvey responses from your students, what insights did you gain into their thinking?
- For many semesters, I have asked on the unit exam, "Compare and contrast prokaryotic and eukaryotic cells." This semester, the results were markedly better...stellar, in fact! Also, on the next unit exam, two students asked if they could use a Venn diagram to answer an essay question. Since the InkSurvey question was the only time we had used Venn diagrams in class, and no one had ever asked me that question before, I interpret it to mean that the students found it to be a handy tool to have in their student toolbox.
Refections on how this has or has not changed practice? How has this changed your thinking about teaching?
- This lesson reminded me that even though a concept seems simple and obvious to me, it needs to be approached multiple times, even in a single lesson, before some students can incorporate it into their understanding. Without the real-time formative assessment input from the students, it would have been easy to gloss over this and have little learning occur.