Mutation, HGT, and superbugs
Tue, Oct 6, 2026 · Week 7 · Genetics of Disease (Medical Interventions)
Today's goal: Explain how mutation and horizontal gene transfer spread resistance genes and create superbugs.
This is a model of the work you should turn in today. Use it to check your own: match the structure and the level of detail, do not copy it. Your data and wording should be your own.
Definitions in my own words:
- Mutation: a random change in a bacterium's DNA. Once in a while a mutation happens to make the cell able to survive an antibiotic.
- Horizontal gene transfer (HGT): when one bacterium passes a gene to another bacterium instead of to its offspring. Resistance genes can move this way, even between different species.
How one resistant cell shares its gene (conjugation): A resistant cell builds a bridge called a pilus to a neighbor, copies its resistance plasmid, and sends the copy across. Now both cells are resistant.
Why superbugs resist several drugs at once: Resistance genes often ride on the same plasmid. One transfer can hand over resistance to multiple antibiotics in a single step, so a cell can become multi-drug resistant without slowly earning each resistance on its own.
Colony-data scenario: On my plate, imagine one of my 14 colonies carried a resistance plasmid. If I added an antibiotic, that colony's descendants would survive and the others would die, so over time the resistant colony would take over the whole plate.
Linking sentence: Careful culturing lets us see resistant strains, resistance spreads through mutation and HGT, and that is exactly why stewardship (using antibiotics sparingly and correctly) matters.
This model shows the level of evidence and organization needed to complete: Completes the resistance-mechanism notebook page: definitions of mutation and horizontal gene transfer, a labeled conjugation diagram, a multi-resistance explanation, a colony-data scenario, and a linking sentence.
- Date and label the entry.
- Record the procedure, observation, or design decision clearly.
- End with what the evidence means and the next step.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Also due today: Photograph and upload the page to your portfolio.
Turn in: HGT and superbugs notebook entry
Go to Schoology to turn this in.
Submit one PDF. Put your first and last name in the document header. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf.
Open Schoology PDF upload helpIf you cannot get in, see Mr. Mendoza. Do not skip the work.
Claim ceiling: Today's evidence supports a classroom claim about today's lesson. It cannot prove causation, diagnose a real patient, or justify action outside this room.
One exam-style question that uses exactly what you practiced today. Try it before you reveal the answer, then read why each choice is right or wrong.
Tap an answer to see the full explanation. Nothing is recorded or graded.
It builds this reusable test skill: Explaining how horizontal gene transfer spreads resistance between bacteria.
- Name the concept or data pattern being tested.
- Cross out choices that violate that rule or the evidence.
- Justify the best remaining choice before checking the answer.