Watching Development Happen
Developmental domain · Lesson 18 of 20 · Principles of Biomedical Science (PBS)
Today's goal: Explain why scientists use model organisms (mouse, zebrafish) and live imaging plus lineage labeling to watch palate fusion, and judge what each tool can and cannot tell us about a human cleft.
What a finished product looks like
This is a model of the work you should turn in. Use it to check your own: match the structure and the level of detail, do not copy it. Your wording should be your own.
Choice: Use the mouse, paired with live imaging (time-lapse microscopy of cultured palate tissue), because the mouse truly fuses a secondary palate and live imaging is what revealed seam-cell extrusion in the first place (PMID:26589921).
What it could show: Whether the medial edge seam cells in the mutant converge, form rosettes, and get squeezed out, or whether they stall, which would point to a seam-removal failure mapping onto a Tgfb3-type cleft.
Honest caution: A mouse result is a strong but not guaranteed bridge to a human because it rests on homology, and we still cannot film Mateo's own embryo, so the finding would be a model for his cleft, not a direct observation of it.
How this was built, step by step
The finished product above did not appear all at once. Here is the path from the question to the turned-in work, so you can follow the same steps.
- 1Start from today's question: How do we actually watch development go right or wrong?
- 2Work the Model and the Explore questions to reason it out before writing anything.
- 3Pull the specific evidence the product needs from the reading and any database you used.
- 4Write it up in the required format: You are choosing a model to investigate one open question about Mateo's : "did the medial edge cells fail to get extruded?" Decide whether you would use mouse or zebrafish, name the imaging tool you would pair with it, and write two sentences: one on what the model could show you, and one honest caution about what it could NOT tell you about a human.
- 5Check it against the rubric, then submit.
| Criterion | Proficient | Developing | Beginning |
|---|---|---|---|
| Complete | Every required part of the artifact is present and filled in. | Most parts are present, but one is missing or left blank. | Several parts are missing. |
| Accurate | The science and data are correct and match the evidence. | Mostly correct, with a small factual slip. | Key science or data is wrong. |
| Scientific reasoning (CER) | States a claim, backs it with specific evidence, and explains the reasoning. | Has a claim and evidence, but the reasoning is thin or missing. | Gives an answer with no evidence or reasoning. |
| Professional communication | Clear, organized, and labeled the way a clinician or scientist would write it. | Readable but disorganized or missing labels. | Hard to follow. |
| Submitted | Turned in the right way (Schoology for routine work) and confirmed. | Turned in, but in the wrong place or unconfirmed. | Not turned in. |
- CompleteProficient: Nothing is left blank: the model fills every part of "You are choosing a model to investigate one open question about Mateo's cleft: "did the medial edge cells fail to get extruded?" Decide whether you would use mouse or zebrafish, name the imaging tool you would pair with it, and write two sentences: one on what the model could show you, and one honest caution about what it could NOT tell you about a human.".
- AccurateProficient: Every number and claim matches the case evidence.
- Scientific reasoning (CER)Proficient: It names a claim, cites the specific evidence, and explains the reasoning, not just the answer.
- Professional communicationProficient: It is organized and labeled like a real chart note.
- SubmittedProficient: It would be turned in on Schoology and confirmed.
WebXam problem for today's skill
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.