Data analysis and limitations
Fri, Apr 16, 2027 · Week 13 · Human Anatomy & Physiology (Human Body Systems)
Today's goal: Analyze their investigation data and write a CER that acknowledges experimental 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.
Parallel case (model only, not today's prompt): a different team tested how caffeine concentration affects the heart rate of Daphnia (water fleas) under a microscope.\n\nClaim: Increasing caffeine concentration raises Daphnia heart rate, showing a dose-response relationship.\n\nEvidence: In the 0 mg/L control, the average heart rate was 180 beats per minute. At 20 mg/L caffeine the average rose to 240 beats per minute, and the 10 mg/L group fell in between at about 210 beats per minute.\n\nReasoning: As the dose of caffeine rose, the biological effect (faster heartbeat) increased. This is what physiology predicts: caffeine is a stimulant that blocks the signals that normally slow the heart, so more caffeine drives more heartbeats per minute. The steady climb from control to 20 mg/L shows the effect scales with dose rather than jumping at random.\n\nLimitations:\n- Small sample size (only a few Daphnia per concentration) means one unusually fast or slow animal could shift the average a lot.\n- Heart rate was counted by eye while watching a fast, tiny heart, so the same beats could be tallied differently by different observers or on different trials.
This model shows the level of evidence and organization needed to complete: Parallel model of the analysis target: a dose-response CER that states a claim, cites two data points, reasons from dose to response, and names two real limitations. Model only. It does not answer today's copper-and-worms prompt.
- 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: Submit your CER on Schoology.
Turn in: Worked CER on a parallel case
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: Reading a dose-response graph and identifying the pattern.
- 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.