Antibiotic Lab Investigation (Day 3 of 3)

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Students will learn the basic details regarding the background history of antibiotics, the nature of bacterial organisms, and explore the phenomenon of antibacterial/antimicrobial resistance in a hands-on manner.

Big Idea

Bacterial infections, the use of antibiotics, and their increasing resistance to many antibiotics is a growing and widespread issue for medical science. Students will investigate this issue in a hands-on lab.

Learner Goals

Note: I recommend that you first check out this resource in order to get the most out of this lesson!

In high school I took several drafting classes and, for a while, I had hoped to become an architect. With respect to planning instruction and teaching, I feel that I can still live out the detailed approach to building something intricate and complex even though the product is a lesson rather than a certain "built environment".

The lesson-planning template that I uploaded to this section is a comprehensive overview of how I approach lesson planning. This template includes the "Big Three" aspects of the NGSS standards: Disciplinary Core Ideas, Crosscutting Concepts, and Science Practices. Of course, there are many other worthy learning goals, skills, instructional strategies, and assessments that can be integrated into a class session. I don't feel compelled to check every box but, rather, use it as a guide to consider various options and tailor the lesson in light of these.

With regard to this particular lesson, I want students to develop some basic knowledge about cell diversity; that is some cells are prokaryotic and others eukaryotic. Furthermore, given the high-stakes issue of antibiotic resistance in medical science, students ought to be informed about the problem and ways to reduce its effects. Finally, students will be formally introduced to the particular inquiry procedures that I want students to follow in this, and every, lab investigation. The scaffolding of knowledge and skills here will serve them well in the sessions of this class.

I hope you get some value from my work! Please find the more intricate details of this lesson plan there.

NOTE: This investigation usually takes 3 class periods (165 minutes for me) to complete.

Anticipatory Set ("Hook")

5 minutes

Since this is an extension of Day 1 and Day 2, make a brief reminder of the goals for the lab and key points covered the previous class periods. 

Instructional Input/Student Activities

30 minutes

(Day 3 of 3)

1. Students ought to carefully measure the zone of inhibition around each antibiotic disk. Be sure to have multiple measures/confirmation by all members of the team to ensure accuracy.

2. Next, student teams are to report out their group data. I use an Excel Antibiotic Lab Class Data Sheet that is populated with each group's data, of which I have eight. I solicit responses from the class on a group-by-group basis. In doing this, all teams get a sense of any variations among team data.

3. I take this opportunity to emphasize the value of repeated trials; in this sense each group represents a single trial. Additionally, I stress the importance of having as large a sample size as reasonably possible. Larger sample sizes (measures of Z.I. for the class) provide an increased confidence in the trends revealed in the data.

4. Students are then prompted to prepare bar graphs according to reported class averages for each quadrant of the Petri dish.

5. Dispose of Petri Dishes according to proper protocol (see Section 1.1.8 of Microbiology Safety Considerations courtesy of Southern Biological). 



Closure: What did we learn? Where do we go from here?

10 minutes

Now that students have investigated the effect (little or great as it may be) between various antibiotic types and E. coli, they should now be able to think more deeply about Molecules to Organisms (LS1), concrete examples of cause and effect (CCs) and a handful of Science Practices (SPs). Use this information to discuss the six prompts on slide 20 of the Antibiotic Lab PPT

Lesson Extension & Follow-Up Activities

10 minutes

Students ought to complete the (L) column of the KWL chart and any incomplete sections of the lab investigation.

Note: This task may be assigned as homework depending on time constraints and student pacing.