Unit 2.3 Challenge Accepted: Open-ended C. elegans/heavy metal investigation or validated simulation; data and conclusions.
Your PLTW coursework: Human Body Systems ▸ Unit 2: Research Ready ▸ Lesson 2.3 Challenge Accepted ▸ "Problem 2.3.1 Challenge Accepted (C. elegans research)"
What to do if absent- 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.
Week overview - Challenge Accepted: a model-organism investigation into heavy metals
Carry out an open-ended C. elegans or simulated heavy-metal investigation, record clean data, and write a conclusion that names its limitations.
- 1Review your hypothesis and the rules for working with a or simulation.
- 2Set up your treatment and control conditions and define what data you will collect.
- 3Run the investigation and record results in a clear, labeled .
- 4Build a graph that lets a reader see the pattern in your data at a glance.
- 5Write a conclusion that states whether your data support your hypothesis.
- 6Name at least two limitations and explain how they could affect your conclusion.
- • You will be able to organize results in a labeled and graph.
- • You will be able to write a conclusion that is supported by your data.
- • You will be able to name limitations that affect how far your conclusion can go.
Daily lessons this week
Open any day for its full lesson, the work due that day, and guided notes.
Written position on heavy-metal exposure responsibility, citing one factual reason and naming one genuine tradeoff in regulation.
Written if-then hypothesis, complete materials list, step-by-step procedure, and at least one consideration with rationale for the C. elegans heavy-metal investigation.
Completed with results for all treatment concentrations and the control, consistent units, and notes on any unexpected observations.
Written CER with a dose-response claim, two specific data-point evidence entries, reasoning linking dose to worm response, and at least two limitations of the investigation.
Completed weekly progress tracker showing submission status for the pre-lab, , graph, and CER, plus a written reflection proposing one concrete improvement to the investigation.
Quick intro to the week
- Hook: toxicologists use tiny organisms to find out what doses are dangerous, and today you run that kind of investigation yourself.
- Today's goal: produce clean data, a clear graph, and an honest conclusion that admits its limits.
- This week's Monday bioethics debate: how much risk is acceptable when testing chemical ?
- Reminder: your graded research report with limitations lives in the PLTW course shell, not on loose paper.
Your PLTW coursework this week
Do this: Advance the PLTW Challenge Accepted benchmark by completing the online evidence for the open-ended investigation in the course shell.
- • Toxicology studies how the dose of a substance like a affects living things.
- • A and graph make patterns in evidence visible to a reader.
- • Every investigation has limitations that bound its conclusions.
- • Record and graph investigation data accurately.
- • Write a conclusion that connects evidence to the hypothesis and states limitations.
📋 PLTW evidence due: research report with , graph, conclusion, and named limitations, submitted on the class site.
All PLTW activities are completed inside the PLTW course environment: this page only gives direction.
This week's PLTW tracker
Your week at a glance. Check off each deliverable as you finish it, then submit so Mr. Mendoza can see how the class is pacing.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
| Day | Date | Focus | Key deliverable |
|---|---|---|---|
| Tuesday | Tue, Apr 13 | Heavy-metal exposure debate | Written position on heavy-metal exposure responsibility, citing one factual reason and naming one genuine tradeoff in regulation. |
| Thursday | Thu, Apr 15 | Hypothesis and protocol | Written if-then hypothesis, complete materials list, step-by-step procedure, and at least one safety consideration with rationale for the C. elegans heavy-metal investigation. |
| Friday | Fri, Apr 16 | Run the investigation | Completed data table with results for all treatment concentrations and the control, consistent units, and notes on any unexpected observations. |
| Thursday | - | Data analysis and limitations | Written CER with a dose-response claim, two specific data-point evidence entries, reasoning linking dose to worm response, and at least two limitations of the investigation. |
| Friday | - | Submit tracker and evidence | Completed weekly progress tracker showing submission status for the pre-lab, data table, graph, and CER, plus a written reflection proposing one concrete improvement to the investigation. |
- First class day: bioethical debate (Monday is a closure)
- T: teacher background notes + PLTW launch task
- W: lab / data or model work
- Th: analysis / CER or design revision
- F: submit tracker + weekly evidence
Due by week's end: Research report with limitations.
5 panels from the illustrated semester.


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.
Lab day: what to bring & watch
This explainer accompanies the PLTW lab protocol: watch it before lab.
What to do when absent
Most days, this class is your PLTW coursework: and PLTW is online and individual. So being out usually just means doing exactly what we did in class, from home.
Open Clever, then myPLTWHow to get there: open Clever and sign in with your Microsoft (district) account. Both myPLTW and Schoology are in Clever. Do the activity in myPLTW. Turn the work in on this site or hand it to Mr. Mendoza, because that is the step that counts as submitted. Schoology only shows your report-card grade later.
You can't do those from home: do this instead: Teacher-posted data/model packet, same objective. Supplemental: Khan: data displays/statistics.
Class still runs. A substitute will post today's plan: complete the online activity above; it's built to be self-guided. Need the concept taught without a teacher? Use this authoritative explainer:
CDC: Lead poisoning preventionVocabulary
Resources & readings
Hand-picked readings, videos, and interactives for this lesson, all free and from authoritative open organizations (NIH, CDC, OpenStax, Khan Academy, PhET, HHMI, and more).




