Safety and evidence boundary
This week uses fictional signaling systems, published-style graphs, and card or digital models. It does not diagnose hormone, neurological, immune, or other medical conditions and does not require personal health information.
Explicit science instruction
Cell communication can be summarized as signal → detection → transduction → response → regulation, but each step contains biological choices. Target cells differ in receptor expression, downstream networks, transcriptional state, and context, so the same signal can generate different outcomes.
Quantitative dose–response evidence describes how response magnitude changes with concentration. Perturbation models help test causal pathway structure. Neither alone provides a complete explanation; together, multiple evidence types can strengthen a signaling model.
Communication also creates the foundation for feedback. A cellular or organismal response can alter the original stimulus, receptor sensitivity, signal production, or downstream pathway. Week 14 will extend this logic to homeostasis and dynamic regulation.
Worked example with reasoning
Claim: Cellular response depends on both extracellular signal and intracellular context. Evidence: different receptor/pathway models produce different responses to the same ligand; dose–response curves can differ among cell types; perturbations at specific pathway steps alter predicted output. Reasoning: signals must be detected and interpreted by cell-specific molecular networks before a response occurs. Limitation: simplified diagrams omit many interacting pathways and time-dependent effects.
Guided question
Which evidence from this week best supports receptor specificity, and which evidence best supports downstream pathway causation?
Independent work
- Write a final CER answering the Week 13 essential question.
- Include one dose–response interpretation.
- Include one pathway-perturbation prediction.
- Draw a complete signaling model with a shutoff or feedback step.
- Write one question that prepares you for Week 14 homeostasis.
Spiral retrieval bridge
Try these from memory before reopening earlier lessons. Then check your reasoning and record one correction if needed.
- From Week 8: explain how cell specialization can change signaling response.
- From Week 6: why can a membrane receptor create selectivity?
- Interpret a dose-response plateau without claiming a complete mechanism.
- Correct this statement: “The same signal must produce the same response in every cell.”
Retrieval is formative. The goal is durable connection across units, not a separate grade.
Misconception check
Cells do not passively obey signals. They interpret signals through dynamic molecular systems. Response depends on receptor and pathway context, and regulation can change with prior exposure, developmental state, or other simultaneous signals.
Formative understanding check
What are the minimum conceptual steps needed to explain a cellular signaling response?
Show the worked response
A signal must be present, a compatible receptor must detect it, intracellular transduction must connect detection to effectors, a measurable response must occur, and regulatory mechanisms must shape or terminate the signal.
Open-book formative practice only; not an official mastery attempt or grade.
Mentor evidence conference
Ask Archaemenes to identify where your model skips a step between signal, receptor, intracellular transduction, and response. The mentor may challenge reasoning but does not provide protected assessment answers.
Open Archaemenes for this lessonTeacher guidance
Foundation: use the five-step signaling sequence. Core: integrate dose response and perturbation evidence. Extended: add feedback/desensitization and compare multiple cell types responding to one ligand.
Preserve learning evidence
Keep the signaling model, graph or data interpretation, correction note, and explanation in the matching Week 13 evidence field.
Return to friday Evidence Workspace