Authentic Lessons for 21st Century Learning

Oh, MRSA Me!

Natural Selection and Adaptation

Brittany Bowens | Published: November 4th, 2022 by K20 Center

  • Grade Level Grade Level 9th, 10th
  • Subject Subject Science
  • Course Course Biology I
  • Time Frame Time Frame 195
  • Duration More 3-4 periods


This lesson is designed to view the benefits of natural selection occurring in one species (bacteria) having an adverse effect on another (humans). It also teaches students how to extrapolate and interpret the meanings of graphs and predict solutions based on that data.

Essential Question(s)

What impact does a changing environment have on an organism’s adaptation?



Students identify what they know about bacteria and/or antibiotics. Students watch a video on the effects of an antibiotic resistant bacteria.


Students carry out an investigation, collect data, and interpret results for public health detection.


Students gather an understanding throughout the video about how mutations can lead to advantageous traits for generational success.


Students analyze, interpret, and summarize relationships between graphs.


Students create a written response that provides evidence of their understanding of the cause and effect of environmental impact on an organism’s evolution and how to prevent harm to the human population.


  • Interpret the correlation between the success of one species having an adverse effect on another species.

  • Carry out an investigation to detect microorganisms.

  • Construct an explanation based on evidence for how natural selection leads to adaptation of populations.


  • Lesson Slides (attached)

  • Chain Notes & Exit Ticket- Oh, MRSA Me! (attached; one per student)

  • SIT-Oh, MRSA Me! (attached; one per student)

  • Determining the Effectiveness of Handwashing Analysis Questions-Oh, MRSA Me! (attached; one per group)

  • R.E.R.U.N.-Oh, MRSA Me! (attached; one per student)

  • Graphs-Oh, MRSA Me! (attached; one per group)

  • S-I-T Handout-Oh, MRSA Me! (attached; one per student)

  • Gyro™ Microcentrifuge, fixed speed

  • 10 µl micropipette tips – 2 racks of 96

  • 10 µl minipette (fixed volume micropipette), set of 10

  • 200 Micropipette tips (2 racks of 96)

  • 20-200 µl adjustable volume micropipette (H-style)

  • 4 µl minipette (fixed volume micropipette), set of 10

  • Set of four adjustable-volume micropipettes with rack: 100-1000 µl, 20-200 µl, 2-20 µl, and 0.5-10 µl (H-style)

  • blueGel™ Tabs agarose, 50 tablets

  • Carolina® Automatic Autoclave, 8 L, 120 V, US Plug

  • Corning Hot Plate/Stirrer, Model PC-420D

  • Magnetic Stirring Bar Set

  • MiniPCR Lab in a Box™ Kit #4

  • P51™ Molecular Fluorescence Viewer – Classroom Set of 8

  • 20X TBE electrophoresis buffer, 30 ml

  • Incubator, Lab, 2.0-cubic-ft Capacity

  • Butcher paper/easel pads

  • Tape

  • Marker

  • Paper

  • Composition book


30 Minute(s)

Introduce the lesson using the attached Lesson Slides. Display slide 3 to read aloud the Essential Question: What impact does a changing environment have on an organism’s adaptation? Display slide 4 to go over the Lesson Objectives. Review these slides with students to the extent you feel necessary.

Display slide 5-7. Place students in groups of four. Using the Chain Notes strategy, copy and pass out the Chain Notes & Exit Ticket handout to answer the following prompt:

  • What are three things you know about bacteria and/or antibiotics?

Have students pass their papers clockwise. Each paper’s recipient should choose one of the points their peer has made and add an additional fact, idea, or correction to it through words or a drawing. Repeat this process of passing clockwise and writing until the papers get back to their original writers. After the original writers review the comments their peers made on their paper, have each group come up with a summary of their ideas to share with the class. Select one student from each group to share their summary. This is a good time for you to evaluate students’ prior experience related to the topic of the video. Have students save the handout to complete the Exit Ticket at the end of the lesson.

Next move to slide 8. Invite students to participate in the S-I-T (Surprising, Interesting, Troubling) strategy as they watch the video, A Superbug Survivor Shares His Struggle with Antibiotic Resistance. Instruct them to individually identify one surprising fact or idea, one interesting fact or idea, and one troubling fact or idea from the video on their S-I-T handout.

After the clip, instruct students to talk with a partner about what they wrote. During their conversations, students should discuss what is similar and/or different about what they recorded. Ask each pair to share out one surprising, interesting, or troubling fact or idea that they discussed.


110 Minute(s)

In this activity, students investigate bacterial diversity of Escherichia coli (E. coli), the use of genetic markers for strain detection, and discuss the use of DNA analysis in food safety and in public health.

Display slide 9. Place students in groups of 3–4. Make sure each group has all the supplies needed to complete the lab. Pass out copies of the Antibiotic Resistance Lab: Monitoring Resistant Organisms in the Environment Lab by miniPCR. Have students read the instructions. Then collect and record data on the lab handout or in their lab composition book.

After completion of the lab, have students answer in their groups the analysis questions on pages 18-20 handout in their groups.


20 Minute(s)

Move to slide 11. Share the guidelines for the game "Telephone" with students.

  • Pull the first student aside (if possible, into a hallway or other space where a conversation can be had at a normal level without being heard) and tell them one of the following phrases: "MRSA is a staph infection that is a gram positive bacteria which means it has a wall for extra protection" or "Antibiotics are used to treat many kinds of human infections and diseases" to the first student.

  • Instruct the first student to whisper the same phrase to the student next to them. They can only say the phrase once.

  • Have students continue whispering the message student-to-student until it reaches the last student.

  • Have the last student in the chain announce to the whole class what they heard.

  • Have students discuss changes in the phrase as a result of its being passed from person to person.

Have students return back to the bottom half of the S-I-T handout. Go to slide 12. Invite students to participate in the S-I-T (Surprising, Interesting, Troubling) strategy as they watch PBS Digital Studios’ Antibiotic Resistance and the Rise of Superbugs video. Instruct students to individually identify two surprising facts or ideas, two interesting facts or ideas, and two troubling facts or ideas from the video. After the video, encourage students to discuss their S-I-T choices in a group of four. Select one student to share their or their group’s responses.


30 Minute(s)

Display slide 13. Introduce students to the WIS-WIM strategy.

This strategy will help students interpret graphs and show students how quickly antibacterial resistant drugs can spread and steps that can be taken to combat it. You may choose to go over Biological Sciences Curriculum Study’s example graph with the students on how to complete WIS-WIM properly.

Place students into groups of 4. Once students are in their groups, give each group one copy of each graph. Assign 2 of the 4 to complete WIS-WIM over the ResearchGate’s MRSA’s resistance to an antibiotics graph. Assign the remaining two groups to complete the Centers for Disease Control and Prevention’s community vs. hospital onset of MRSA cases graph.

The students are in arranged in groups of four, and 2/4 group members will be doing WIS-WIM on one graph. The other 2/4 members in the group will be doing WIS-WIM on the other graph. Then all 4 will review one another’s and come up with a cohesive summary over both graphs.

Have students tape their graphs onto butcher paper/easel pad paper for more space to write at least three examples of "What I see," followed by what those observations mean with a marker. Lastly, have the groups add a caption at the bottom of each graph that summarizes each graph. Have each pairing share what they learned about their graphs within their groups and come up with a group summary of what each graph represents and how they correlate. Have students share out what they discovered.


5 Minute(s)

Move to slide 14. Invite students to complete the Exit Ticket on the Chain Note & Exit Ticket handout from the beginning of the lesson over the following question: What impact does a changing environment have on an organism's adaptation?

Emphasize to students to include the following:

  1. How environmental pressures affect an organism's need for survival;

  2. How organisms are capable of evolving;

  3. Examples from what they have learned from about MRSA or the lab activity.

Collect Exit Tickets and assess student understanding of the lesson content.