Rough draft.This research track is under review with Dr. Atit's lab. Content and sequence may still change.
The Baby Mateo Case
Developmental domainPrinciples of Biomedical Science (PBS)Lesson 14 of 20Your seat: Developmental biologist (failure-point mapper)
Mapping the Failure, Which Step Breaks for a Cleft Lip Versus a Cleft Palate
Discovery question
If you are handed a specific , can you read it backward to the one developmental step that failed?
💡 Because we know the normal build sequence, a phenotype can be read backward to the single step that failed, and a one-site cleft with nothing else wrong points to a local rather than a body-wide .
The plan
Prerequisite check
Before this page, you should know
- The is a single flat layer of cells that wraps embryonic skin and mouth lining and acts as a controlled non-stick coating.
- At true sites the peels away on cue so the layers underneath can join; elsewhere it keeps wrong surfaces apart.
Today's new idea is only
Because we know the normal build sequence, a phenotype can be read backward to the single step that failed, and a one-site cleft with nothing else wrong points to a local rather than a body-wide .
Learn first
What you will learn
Goal: Map a phenotype back to the exact developmental step that failed, and distinguish a single local from a broad, multi-step .
Know by the end
- The normal build order is: week 4 to 6 lip , week 6 shelf growth, week 8 shelf elevation, weeks 8 to 12 shelf and fusion.
- A lip points to a failure of step 1 (medial nasal plus maxillary ); a cleft only points to a failure of palate growth, elevation, or fusion.
- A means the body plan is normal but one seam did not close; a mis-sets the whole body plan so many structures form wrong at once.
- An is limited to one structure with no other anomalies present.
Learn first
Model: Three patients, three failure points (contrast card)
Match each to the build step that failed (DATA_TABLES.md contrast card; PMID:26589921; PMID:16282779).
Patient A, LIP only: the lip and gum are clefted but the roof is intact. Step 1, lip (medial nasal plus maxillary), failed in weeks 4 to 6.
Patient B, only: the roof of the mouth is clefted but the lip is intact. One of steps 2 to 4 (palate growth, elevation, or ) failed in weeks 6 to 12.
Patient C, LIP AND : both the lip and the roof are clefted. Step 1 fails early and also derails the later palate steps, weeks 4 to 12.
Notice: each is a failure of a or growth step in the face. None lists a brain, heart, or limb defect. The failure is local to the face-building steps.
Do the work
Explore (work the model before reading on)
- List the four steps in order and the week each happens.
- For a of the lip only (Patient A), which numbered step failed?
- Patient B has a but a normal lip. Why does that tell you the lip step (step 1) must have worked, even though a later step did not?
- Compare Patient A and Patient C. Both have a lip . What extra thing went wrong in Patient C, and why does failing step 1 early make the later steps more likely to fail too?
- Imagine a baby with a one-sided of the lip and and NO other problems anywhere in the body. Is that better explained by one local sequence that failed, or a body-wide patterning program broken everywhere? Defend your choice using the build-sequence idea.
The plan
Guided notes
1
Reading a phenotype backward
Model start: A phenotype is the visible result you can observe, here the specific . Because we know the normal build sequence, we can read a phenotype backward to the broken step.
- A lip points to a failure of ____ (step 1, lip of medial nasal plus maxillary processes) in weeks 4 to 6.
- A only points to a failure of one of the steps: ____ (growth, elevation, or ) in weeks 6 to 12.
2
Fusion failure vs patterning defect
- A ____ () is when the building blocks are present and the body plan is normal but one specific seam did not close.
- A ____ () is broader: the whole body plan is mis-set so many structures form wrong at once.
- When a defect is limited to one structure with no other anomalies, we call it an ____ (isolated) defect.
Explore
Reading the Research
What to read
Read the title and the abstract only, not the whole paper. Lan & Jiang 2015, Cellular and Molecular Mechanisms of Palatogenesis (Curr Top Dev Biol)
Why this source matters
This is the published evidence behind today's idea: Because we know the normal build sequence, a phenotype can be read backward to the single step that failed, and a one-site cleft with nothing else wrong points to a local rather than a body-wide .
Words to unlock first
Reading moves
- Skim the title and abstract first to get the gist.
- Circle the one sentence that states the main claim.
- Box the evidence the authors give for that claim.
- Mark one sentence that confuses you, and move on.
Stop point
You do not need the methods or statistics yet. If a sentence is about lab technique or math you have not learned, mark it and skip it.
Your output
Write one claim-evidence sentence: what this source claims, and the one piece of evidence that backs it up.
Where this fits
Tested on (Ohio WebXam)
Genetics of Disease · 072130
PLTW lesson
MI · Developmental domain · PLTW PBS 072110
WebXam domain
Bio-Molecular Technology
Evidence to produce
Open Mateo's case summary: a complete cleft of the lip and palate on the left side, and a newborn exam that found no other birth defects. Write three sentences: (1) which step or steps his cleft points to, (2) whether his pattern looks more like an isolated local fusion failure or a body-wide patterning defect, and (3) what evidence in his exam supports your answer. Do not name a diagnosis; just map the failure and classify the pattern.
Lab / skill
Principles of Biomedical Science (PBS)
The plan
Track your progress today
Check these off as you work through the lesson, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
Check off as you finish
- Read the Model and answered the Explore questions.
- Filled in the guided notes in my own words.
- Defined the new vocabulary with an example.
- Built the producible: Open Mateo's case summary: a complete cleft of the lip and palate on the left side, and a newborn exam that found no other birth defects. Write three sentences: (1) which step or steps his cleft points to, (2) whether his pattern looks more like an isolated local fusion failure or a body-wide patterning defect, and (3) what evidence in his exam supports your answer. Do not name a diagnosis; just map the failure and classify the pattern.
- Wrote my Claim, Evidence, and Reasoning exit ticket.
Pick your period and code first.
Check yourself
Exit ticket (Claim, Evidence, Reasoning)
- Claim: Mateo's finding looks like an isolated, local rather than a body-wide .
- Evidence: His record shows a of the lip and and ____ other birth defects.
- Reasoning: Because a would usually disturb ____ structures at once, a single with everything else normal fits a ____ failure better.
How this is graded (rubric)
For: Open Mateo's case summary: a complete cleft of the lip and palate on the left side, and a newborn exam that found no other birth defects. Write three sentences: (1) which step or steps his cleft points to, (2) whether his pattern looks more like an isolated local fusion failure or a body-wide patterning defect, and (3) what evidence in his exam supports your answer. Do not name a diagnosis; just map the failure and classify the pattern.
| 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. |
How the model answer scores against this rubric
- CompleteProficient: Nothing is left blank: the model fills every part of "Open Mateo's case summary: a complete cleft of the lip and palate on the left side, and a newborn exam that found no other birth defects. Write three sentences: (1) which step or steps his cleft points to, (2) whether his pattern looks more like an isolated local fusion failure or a body-wide patterning defect, and (3) what evidence in his exam supports your answer. Do not name a diagnosis; just map the failure and classify the pattern.".
- 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.
Explore
Where this leads: careers
Developmental biologist Pediatric geneticist
What's next: We can now map which step failed and see that Mateo's looks like an isolated . But mapping a failure is not fixing it. Each step happens in a narrow calendar window. Is there a moment after which the step can no longer be repaired, so the becomes locked in?