Analyze tox results
Fri, Sep 18, 2026 · Week 4 · Principles of Biomedical Technology (Principles of Biomedical Science)
Today's goal: Interpret biomolecule and toxicology data with a CER and assess method limitations.
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.
Claim: Water Sample B is contaminated with coliform bacteria.\nEvidence: On the coliform indicator plate, Sample B produced pink colonies with a metallic sheen, matching the positive control that was inoculated with a known coliform strain, while the negative control plate (sterile buffer) stayed clear with no colonies. In the dilution series, the undiluted sample grew a dense lawn, the 1:10 dilution grew about 40 colonies, and the 1:100 dilution grew about 5 colonies.\nReasoning: A plate counts as positive only if it matches the positive control and differs from the negative control, and Sample B did both, so the pink metallic colonies are evidence of coliforms rather than a stray color. The steady drop in colony count as the sample was diluted is a dose-response pattern, which shows the colonies came from bacteria carried in the sample and not from contamination introduced during plating. Together the control comparison and the dilution trend make the positive reading trustworthy.\nLimitation: This indicator plate confirms that coliform bacteria are present but does not identify the exact species or prove the water is unsafe to drink, so it cannot stand alone as a public-health conclusion and would need a confirmatory test.
This model shows the level of evidence and organization needed to complete: A claim-evidence-reasoning paragraph interpreting an indicator-plate result against controls, using the data table as evidence and citing the dose-response pattern, with a stated method limitation.
- Write one defensible claim.
- Choose specific evidence that supports the claim.
- Explain the scientific rule that connects the evidence to the claim.
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: Upload your CER and annotated data table to the tracker by end of class.
Claim ceiling: Today's evidence supports a classroom claim about analyze tox results. 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: Interpreting unknown results against controls and reading a dose-response trend.
- 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.