This class runs in two periods and they do not do the same lesson on the same day. You are reading the Period 6A-7B calendar, the one with John Carroll bioethics on Mondays.
Analyze tox results
Do now
Interpret biomolecule and toxicology data with a CER and assess method limitations.
- Hand in
- CER stating which biomolecules are present in each unknown, using Wednesday's data table as evidence and citing comparison to positive and negative controls in the reasoning.
- Where
- Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted.
You get two school days for every day you were absent, so this deadline moves with you.
If the form offers you a saved draft, choose New draft. If the Assignment box comes up empty, type it exactly: Analyze tox results
Looking at your data from Wednesday, which unknowns are truly positive when you hold them against your controls, and does your toxicology dilution data show that more concentration really caused more effect?
Interpret and toxicology data with a CER and assess method limitations.
- • I can interpret indicator results against controls.
- • I can describe a dose-response trend and its limits.
- How do you decide an unknown is really positive and not just showing the reagent's own color?
- In your toxicology data, what happened to the effect as the concentration went up?
- 1Compare unknown-sample results to your control results.
- 2Write a CER: which biomolecules are present in each unknown?
- 3Analyze the dose-response trend in your toxicology dilution data.
- 4Identify two variables that could produce a .
- 5State one limitation of indicator tests for conclusions.
What did this day actually feel like?
Analyze tox results
We compared unknowns against our controls and wrote a CER on which biomolecules are present in each. Then the toxicology piece, which was a dilution series showing dose response. Same substance, increasing concentration, and you can watch the effect climb.
The idea underneath is that the dose makes the poison. Almost anything is harmless at a low enough concentration and dangerous at a high enough one. That reframed a lot for me, because I had been thinking of chemicals as either safe or not safe.
AT HOME, THE WEEKEND BEFORE MON SEP 21 Submit evidence data Packet day. Data table with controls, dose response description, CER, limitations. The limitations section is now a required part of everything we hand in, and I have stopped resenting it. Writing "my negative control was clean so I trust these results" is a sentence that means something.
Turned in: full week packet → recorded in Class Records
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
The same day, drawn.
The dose makes the poison. Almost anything is harmless at a low enough concentration. I had been sorting chemicals into safe and not safe.
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
🛠 Get unstuck · pick your level
PBS Unit 1 is one case, not twenty topics. A woman was found dead at home, and you are the team that has to work out how she died. You get the evidence in pieces, in the order a real investigation would get it, and you are not told the answer at any point.
Gel interpretation and the toxicology screen. You build a standard curve, decide which of two readings per sample is usable, and report a concentration. Two samples cannot be quantified at all and your job is to say why rather than to force a number.
- Activity 1.1.6 DNA Analysis
- Activity 1.2.3 Forensic Toxicology
Look this up in myPLTW to check you are in the right place.
What you cannot claim in this case, on any day
- A physiological chart records breathing and heart rate. It does not measure lying, and nothing in this unit produces a deception call.
- Microscopic hair comparison can support consistency or support exclusion. It cannot identify a person.
- A fingerprint pattern class can narrow a field or exclude a person. By itself it cannot name a source, and it never says when or why a finger touched something.
- A scheduled event is not proof that a person was there. Time of death is not established by the early evidence.
- Repeating a measurement reduces random error. It does not remove a calibration offset, a shared bias, contamination, or a weak method.
Where the case record itself lives: the case file, the source packet and the timeline are PLTW materials and are handed out on paper in class. They are not posted here.
Do the work · 80-minute blockfirst 5 min = hook▸
💡 Big idea: A result becomes evidence only when compared against controls because a color change in can come from interference or , so interpretation depends on the comparison, not the color.
- 0:00Return Wednesday data tables; identify any groups whose showed a color change (class discussion of what that means)
- 0:12Walk through interpretation logic: matched, flat, unknown matches positive = positive result
- 0:25Students interpret their unknown results, noting biomolecules present or absent for each sample
- 0:40Analyze dilution series: describe the dose-response trend in words; identify threshold if visible
- 0:55CER writing: claim (which biomolecules present), evidence (), reasoning (comparison to controls)
- 1:10List two false-positive sources and one limitation of indicator tests; preview Friday submission
- • Your data from Wednesday is only half the story. Today we interpret it. And interpreting data means comparing your unknowns to your controls, not just reading a color.
- • If your changed color too, that is a problem. It tells you something went wrong with your technique or your reagent, and your unknown results may not be valid.
- • We will also look at your dilution series and describe the dose-response relationship. In toxicology, this relationship is the foundation of every limit ever set, from drinking-water standards to medication dosing.
- • Your CER today is your scientific argument about what biomolecules are in each unknown. Evidence comes from the ; reasoning comes from the comparison to controls.
- • An unknown result is interpreted as positive only if it matches the and differs from the .
- • A dose-response relationship shows that as concentration increases, the measured effect increases; a threshold is the concentration below which no measurable effect appears.
- • Common sources of false positives in indicator tests include cross- between tubes, using the wrong reagent concentration, and interference from pigments in the sample.
From Scene to Lab: designing evidence tests and meeting biomolecules · Analyze tox results
Day 3 of this lesson. Open this exact section in myPLTW (find it in Clever, Microsoft sign-in), then do the work below.
Do this: In myPLTW, open Lesson 1.1 Investigating the Scene and go to Activity 1.1.6 DNA Analysis, then open Lesson 1.2 Master the Morgue and go to Activity 1.2.3 Toxicology. Enter your interpreted results in the first and your dose-response description in the second.
Mark Activity 1.1.6 DNA Analysis and Activity 1.2.3 Toxicology complete in myPLTW.
You collected data Wednesday. By the end of today your CER and dose-response description should both be done.
Written CER with controls-based interpretation, plus your myPLTW entries in Activity 1.1.6 DNA Analysis and Activity 1.2.3 Toxicology.
The official PLTW activity stays inside myPLTW. If myPLTW will not open, use F1 and E1-E3 on this page to complete today's local evidence decision, then make up the official activity when access returns. Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted.
Check things off as you work, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible through the submission route shown below.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
From Scene to Lab: designing evidence tests and meeting biomolecules · Analyze tox results
In myPLTW, open Lesson 1.1 Investigating the Scene and go to Activity 1.1.6 DNA Analysis, then open Lesson 1.2 Master the Morgue and go to Activity 1.2.3 Toxicology. Enter your interpreted results in the first and your dose-response description in the second.
You collected data Wednesday. By the end of today your CER and dose-response description should both be done.
This is how Mr. Mendoza sees the class keeping pace with PLTW. Be honest, it only helps if it is accurate.
🎯 Interpret and toxicology data with a CER and assess method limitations.
- Compare unknown-sample results to your control results.
- Write a CER: which biomolecules are present in each unknown?
- Analyze the dose-response trend in your toxicology dilution data.
- Identify two variables that could produce a .
- State one limitation of indicator tests for conclusions.
CER: CER stating which biomolecules are present in each unknown, using Wednesday's as evidence and citing comparison to positive and negative controls in the reasoning.
Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted. Use the checklist just below and upload by 11:29 PM for full credit. Absent with an excused absence? You get two school days for every day you were absent, so this deadline moves with you.
| Task | Who |
|---|---|
| Compare unknown-sample results to your control results. | _______ |
| Write a CER: which biomolecules are present in each unknown? | _______ |
| Analyze the dose-response trend in your toxicology dilution data. | _______ |
| Identify two variables that could produce a . | _______ |
| State one limitation of indicator tests for conclusions. | _______ |
Working solo? Put your own name in "Who" for every row.
- I can interpret indicator results against controls.
- I can describe a dose-response trend and its limits.
- 1Do thisInterpret biomolecule and toxicology data with a CER and assess method limitations.
- 2Use this resource
- 3Submit thisCER: CER stating which biomolecules are present in each unknown, using Wednesday's data table as evidence and citing comparison to positive and negative controls in the reasoning.
- 4Submit it here
- 1Open the form. It must say For students at the top: if it says For parents and guardians, press Back and pick I am the student.
- 2If it offers you a saved draft, choose New draft: an old draft brings back the old assignment.
- 3Sign in with your district Microsoft account, not a personal one.
- 4Check the Assignment box says today's assignment from this page, then pick your period and type your student ID, all nine digits.
- 5Attach your file and press Submit. The thank-you page is your receipt.
Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted. Principles of Biomedical Technology (Principles of Biomedical Science) › From Scene to Lab: designing evidence tests and meeting biomolecules › CERTurn it in
Learn it · deck, reading, and vocabulary▸
The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.
Generated from this lesson's canonical data with a red-team citation check.
Indicator tests produce valid evidence only when positive and negative controls confirm the reagents work, so cross- must be prevented because a is invisible without controls.
A result becomes evidence only when compared against controls because a color change in can come from interference or , so interpretation depends on the comparison, not the color.
A research team lays out its question, variables, controls, sampling plan, measurement record, and analysis before deciding what the data support.
- Which variable is changed or compared?
- Which conditions and measurements must stay consistent?
- Which conclusion is inside the study's evidence boundary?
Define variables, controls, sampling, units, and the analysis plan before interpreting a result; analysis cannot repair biased or inconsistent measurement.
A well-organized classroom study can still be limited by , measurement quality, confounding, and the population represented.
- • Question and variable cards map to the study design.
- • Control and measurement cards map to fair, reproducible data collection.
- • The conclusion card maps to a bounded claim supported by the analysis.
Driving question: Looking at your data from Wednesday, which unknowns are truly positive when you hold them against your controls, and does your toxicology dilution data show that more concentration really caused more effect?
What you already know: Indicator tests produce valid evidence only when positive and negative controls confirm the reagents work, so cross- must be prevented because a is invisible without controls.
New idea: A result becomes evidence only when compared against controls because a color change in can come from interference or , so interpretation depends on the comparison, not the color.
Visual or model: F1. F1. A lesson illustration or teaching diagram for Analyze tox results. Use it with E1-E3; it is a model or context image, not experimental or patient data. What to notice: Use the labels and arrows in F1 to identify the relationship that supports Analyze tox results.
- Observe or measure the relevant feature in analyze tox results.
- Organize the observation with a stable evidence ID.
- Apply this rule: Define variables, controls, sampling, units, and the analysis plan before interpreting a result; analysis cannot repair biased or inconsistent measurement.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: Looking at your data from Wednesday, which unknowns are truly positive when you hold them against your controls, and does your toxicology dilution data show that more concentration really caused more effect?
What the evidence supports: E1-E3 and F1 support the daily take-home when the response meets the stated success criteria.
What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice.
Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.
Environmental health risk is characterized by integrating hazard, dose-response, exposure, and uncertainty; an observed association or model result does not by itself establish individual causation.
Limit: A classroom dataset cannot represent every exposure route, susceptible group, confounder, or long-term outcome.
Define variables, controls, sampling, units, and the analysis plan before interpreting a result; analysis cannot repair biased or inconsistent measurement.
Limit: A well-organized classroom study can still be limited by , measurement quality, confounding, and the population represented.
You can interpret indicator results against controls.
Limit: E3 defines the classroom product or success criterion. It is not independent scientific evidence and cannot justify a clinical or causal claim.
PLTW-PBT@P67-2026-09-18 · Simulated classroom evidence scenario
Your role: biomedical team member
Decision: Your team must decide what the evidence from analyze tox results supports before submitting the claim-evidence-reasoning response named on the lesson page.
- • Select the option best supported by E1-E3.
- • Select a reasonable alternative and name the evidence it would require.
- • Delay the claim because the evidence does not distinguish the options.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the claim-evidence-reasoning response.
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.
Reason for review: Your team must decide what the evidence from analyze tox results supports before submitting the claim-evidence-reasoning response named on the lesson page.
Context: A result means nothing on its own; it becomes evidence only when you compare it to controls and account for what could have faked it, because interpretation, not observation, is where science happens.
- • T1: Compare unknown-sample results to your control results.
- • T2: Write a CER: which biomolecules are present in each unknown?
- • T3: Analyze the dose-response trend in your toxicology dilution data.
- • T4: Identify two variables that could produce a .
- • T5: State one limitation of indicator tests for conclusions.
- • E1: Environmental health risk is characterized by integrating hazard, dose-response, exposure, and uncertainty; an observed association or model result does not by itself establish individual causation.
- • E2: Define variables, controls, sampling, units, and the analysis plan before interpreting a result; analysis cannot repair biased or inconsistent measurement.
- • E3: You can interpret indicator results against controls.
Measurements: Use only the measurements, units, graph, or counts supplied in today's task. No additional patient measurement is implied.
Figure finding: Teaching diagram for Analyze tox results. Use the labels and arrows to identify the decision-relevant relationship. This is a teaching model, not patient or experimental data.
Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.
= final volume / sample volume. New concentration = starting concentration / dilution factor.
Mix 1 mL of sample to a final volume of 10 mL. The is 10. A 100 mg/mL starting sample becomes 10 mg/mL.
Use the same volume units before dividing. Concentration keeps its original concentration unit.
Apply the same setup to one supplied dilution or dose. Show the factor, new value, units, and a reasonableness check.
Students often think Students think a dose-response means any dose causes an effect, so they assume even the smallest concentration must do something measurable.. The trap: That is a trap because most dose-response relationships have a threshold, a concentration below which no effect appears; the effect rises with dose only above that threshold, so low concentrations can read as zero and still be part of the trend.
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.
- CER:
- Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
- SOP:
- Standard Operating Procedure, the exact steps to follow (especially in a lab).
- Tracker:
- Your PLTW progress log where you record completed evidence.
- myPLTW:
- The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
Hand-picked readings and interactives for this lesson, from authoritative open organizations and PLTW's own public course outline.
Check yourself · commit, then reveal▸
Claim ceiling for this check: 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.
An unknown and the negative control both turn slightly orange with Benedict's, while the positive control turns deep orange. Is the unknown positive for sugar? Explain.
Write an answer and pick a confidence to unlock the key.
Go further and get help▸
Run this before you touch the bench. It is built from the real lab procedure, so the decisions you make here are the ones you will make with the equipment in your hands. This lesson has more than one, and they cover different skills.
What today's skills lead to. These are real health-science careers this course builds toward. Tap one to see, on the US Department of Labor's O*NET site, what the job actually involves, what it pays, and how fast it is growing.
Today is individual work you can do from home: complete the same target above, then submit your CER.
Turn it inSubmit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted.
Class still runs. Complete the online activity above (it's self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
Khan Academy: macromolecules- CompleteEvery required part of the artifact is present, nothing left blank.
- AccurateThe science and the data are correct and match the evidence.
- Scientific reasoningYou explain your claim with evidence and reasoning (CER), not just an answer.
- Professional communicationClear, organized, labeled, and written the way a clinician or scientist would.
- SubmittedTurned in through the one route named under Submit here and confirmed by the form receipt or the named physical handoff. Not in Schoology: that is where the report-card grade appears later.