Body Systems, Signals & Homeostasis — Investigation · Life Science: Biology, Grade 10
Trace interactions among body systems and explain regulation and defense.
Evaluate a Feedback Model
Investigate
What pattern is consistent with regulation, and what remains unknown?
Use three sessions: define question, boundary, model and route; collect or analyze the supplied repeated records; then graph, explain, revise and submit the notebook. Home-study activities do not certify NYSED laboratory minutes or mandated investigations.
Materials
- Supplied fictional response graph data
- Graph paper
- Notebook
Before you begin
Use the supplied paper-and-data model. This activity requires no biological samples, cultures, personal health information, or tests on people.
Plan a fair test
Time follows a standardized model input; condition and signal are observations. This is an illustrative system, not a person’s health measurement. Time association alone does not establish the complete mechanism.
Method
- Draw a causal model: input → condition change → signal → response → effect on condition.
- Graph the condition and signal separately with labeled axes.
- Locate their peaks and describe any delay.
- Compare the condition with the starting range by the final observations.
- State a prediction if the responding tissue could no longer detect the signal.
- Name evidence that would test that prediction without using personal health data.
Open the investigation data (illustrative)
Illustrative data authored for this activity, not an actual experiment or an official mandated investigation. Use them as supplied evidence, not as your own observations.
| Time (min) | Condition (model units) | Signal (model units) |
|---|---|---|
| 0 | 90 | 5 |
| 20 | 130 | 10 |
| 40 | 145 | 25 |
| 60 | 115 | 20 |
| 90 | 95 | 8 |
| 120 | 90 | 5 |
Analyze and explain
- Which parts of the table are consistent with negative feedback?
- Why does the table not prove that the signal alone caused the return?
- How could a target-cell receptor test strengthen the model?
- Separate collected measurements from the supplied illustrative records.
- Explain how labeled mechanisms constrain the pattern rather than only restate the graph.
- Propose a further comparison that could distinguish an alternative explanation.
What a strong explanation includes
- Draws a loop returning to the original condition
- Cites timed values and possible delays
- Separates consistency from proof of cause
- Proposes a matched intervention or additional mechanistic observation
- State units, boundary, comparable conditions and model assumptions.
- Retain a first explanation and an evidence-supported revision.
Parent / teacher guide: discuss after the investigation
The condition rises from 90 to 145, the signal rises, and the condition later returns to 90 while the signal decreases. This is consistent with a negative-feedback model. Other changing processes could also contribute. A controlled model test could compare normal versus blocked receptor response with the same input; direct response evidence would strengthen the proposed link. A complete response also states the system boundary, units, matched conditions and limitations. Distinguish supplied illustrative outcomes from collected measurements, and explain why your revised mechanism fits the relevant evidence. Different observations should be interpreted rather than replaced to match the example.
Compare this model with the learner’s actual evidence. Different measurements can support a different conclusion; check the reasoning and limitations, not matching wording.