Clue 1: Orient yourself
What do the travelers share before they choose a workshop?
Use the labels and the picture's left-to-right, near-to-far, or before-and-after order. Name only what you can point to.
The question
What do the travelers share before they choose a workshop?
Why it matters: The face forms through a timed sequence of growth, movement, and joining. Locating the missed step helps researchers ask a testable question instead of treating every cleft as the same process. Today you practice the professional reasoning behind that work: Cranial neural crest cells leave the neural folds as flexible builders that can become several craniofacial tissues.
On your WebXam
Explaining why neural crest cells must undergo EMT before they can migrate
For life
Having a gene is not the same as using it.
Principle: Having it is not using it
Five principles we return to
Having it is not using it
Same instructions, different switches
Same look, different cause
Change one thing and watch
Boss or doorman?
Decides the result or only allows it
Held down, not gone
Remove the brake and it returns
Many roads, one ending
One result can begin many ways
Try the everyday version first
Students leave one school for specialized apprenticeships
An apprenticeship lets learners begin with shared training and then enter different specialties. Their later jobs depend on which training path they use.
Do not jump to the biology yet. Treat the picture as a small system. Track its parts, follow one change at a time, and keep more than one explanation open until the picture supplies a way to separate them.
Clue 2: Trace one change
What changes when they leave the starting building?
Follow one object, stage, or path. Point to the first place where the situation changes instead of jumping to the ending.
Clue 3: Keep the cause open
Why must their options remain open during the journey?
List more than one explanation that still fits. Name the extra observation that would help you separate those possibilities.
Now inspect the illustration
Work from the visible evidence. A useful answer names the part of the picture that supports it and leaves unknown causes open.
- 1What do the travelers share before they choose a workshop?
- 2What changes when they leave the starting building?
- 3Why must their options remain open during the journey?
Tier 1 check
Finish with the everyday model
Use the everyday picture to answer today's question in plain words: What do the travelers share before they choose a workshop?
You can complete today's required check without opening the technical details below.
Ready for the real names? Optional tier 2
Technical rules and limits
Rule 1: A starting population can share one origin.
Rule 2: Cells change behavior before they move.
Rule 3: Signals at the destination help narrow cell fate.
Where the analogy stops: Cells do not choose careers. The analogy models shared origin and later specialization.
Carry the previous idea forward
The face forms when named tissue prominences grow into position and join specific neighbors.
Today's technical takeaway
Cranial neural crest cells leave the neural folds as flexible builders that can become several craniofacial tissues.
Now map the same rules onto biology
Follow cranial neural crest cells from neural fold to facial mesenchyme
Leave the school
Delaminate from the neural folds
Change travel behavior
Undergo epithelial-to-mesenchymal transition
Enter a workshop
Differentiate within craniofacial destinations
Educational illustration, not a clinical photograph. Use the labels and evidence cards to make the biological claim.
Mateo's case file: evidence supplied in this lesson
DEV03-E1
Cranial neural crest cells arise near the closing neural folds.
Why it matters: They share an early origin before entering the face.
DEV03-E2
They undergo EMT and delamination before migration.
Why it matters: They must loosen epithelial attachments and become mobile.
DEV03-E3
Their descendants form much craniofacial bone, cartilage, and connective tissue.
Why it matters: Their early state supports several later fates.
Make the clinical decision
You are explaining lineage tracing to a new lab intern.
The intern claims every facial bone cell began as a mature bone cell at the neural fold.
ACorrect the claim: mobile multipotent neural crest cells specialize later.
BAgree that mature bone cells migrate from the neural fold.
CClaim all facial tissues come from one mature cell type.
Choose the correction and cite evidence for both mobility and later specialization.
Evidence required
DEV03-E1 + DEV03-E2 Claim ceiling
You may describe lineage potential. You may not claim that every craniofacial tissue comes only from neural crest.Go deeper Optional tier 3
Everything required for today is above. Open these only if you want the explainer, source trail, or download files.
The everyday model and Tier 1 check are the complete required path for this lesson.
Use these checks to keep your place. They are not turned in through the portal.
Check off as you finish
- Worked through the everyday picture and answered its three questions.
- Completed the Tier 1 check in plain words.
Turn in: Developmental lesson 3: Where Do the Cells That Build the Face Come From?
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.
Optional legacy technical materials Open only if you want the original notes, vocabulary, artifact, and CER work
Before this page, you should know
- Five prominences surround the early mouth (the ): one , a paired , and a paired .
- Nasal pits split the into the inner medial nasal processes and the outer lateral nasal processes.
Today's new idea is only
Most of the face is built by cranial that form at the crest of the neural folds and break free by an -to-mesenchymal transition.
Goal: Describe the origin of cranial at the edges of the neural folds, explain by -to-mesenchymal transition, and state why these cells are called .
Know by the end
- The cells that build most of the face are cranial , which form at the crest of the neural folds where the folding meets.
- To leave home, undergo by an , switching from a stuck-together sheet cell to a free, crawling cell.
- are : one cell can become bone, , , dermis, and more.
- Because they supply the prominences, anything that reduces their number, survival, or release can leave a too small to fuse.
1
Where the face cells are born
Model start: The cells that build most of the face are the cranial , and they form at the crest of the neural folds where the edges of the folding meet.
- To leave home they undergo ____: they loosen from the sheet and break free.
- The underlying change is an -to-mesenchymal transition, switching from a stuck-together ____ cell to a free, crawling ____ cell.
2
Multipotent raw material
- These cells are ____, meaning one cell can become many cell types such as bone, , , and dermis.
- Anything that reduces their number, survival, or release can leave a too small to reach across and ____.
3
An honesty note
- This lesson explains the cell source for ____ development; we are not claiming Mateo had a defect.
- We are learning the toolkit so the team can later weigh each possible ____ point.
Everything you need for today is on this page. These links are optional.
What to read
Read the short plain-language explanation written for this lesson. Plain-language explainer for this lesson
Why this source matters
This explanation gives you the background for today's idea without making you decode a research paper: Most of the face is built by cranial that form at the crest of the neural folds and break free by an -to-mesenchymal transition.
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
Stop after the final 'Use it now' section. The research citations are available separately for advanced readers.
Your output
Write one claim-evidence sentence: state the main idea, then name the example or evidence that supports it.
Where this fits
Tested on (Ohio WebXam)
Genetics of Disease · 072130
PLTW lesson
MI · Developmental domain · Cell differentiation and multipotent populations that build the face
WebXam domain
Molecular and Genetic Technology
Evidence to produce
Sketch a 3-panel comic of one cranial neural crest cell: panel 1 sitting in the neural fold as part of a sheet, panel 2 undergoing EMT and delaminating, panel 3 free and ready to travel. Under panel 3 write one sentence naming a real fate it can become inside a facial prominence.
Lab / skill
Principles of Biomedical Science (PBS) · Medical Interventions (MI)
Everything required for today's decision is already in the case file and plain-language explainer. The links below are original papers and database records for teachers and advanced readers, not assigned student reading.
- Lan & Jiang 2015, Cellular and Molecular Mechanisms of Palatogenesis (Curr Top Dev Biol)
- Mishina & Snider 2014, Neural crest cell signaling pathways critical to cranial bone development (Exp Cell Res)
- Liao et al. 2022, Gene regulatory network from cranial neural crest cells to osteoblast differentiation (Cell Mol Life Sci)
- Claim: The cells that fill the facial prominences come from the cranial .
- Evidence: form at the ____ of the neural folds and undergo ____ (EMT) to break free and migrate.
- Reasoning: Because these cells supply the prominences, the face cannot be built normally unless they are made and released in adequate numbers.
How this is graded (rubric)
For: Sketch a 3-panel comic of one cranial neural crest cell: panel 1 sitting in the neural fold as part of a sheet, panel 2 undergoing EMT and delaminating, panel 3 free and ready to travel. Under panel 3 write one sentence naming a real fate it can become inside a facial prominence.
| 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 through the route named under Submit here 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 "Sketch a 3-panel comic of one cranial neural crest cell: panel 1 sitting in the neural fold as part of a sheet, panel 2 undergoing EMT and delaminating, panel 3 free and ready to travel. Under panel 3 write one sentence naming a real fate it can become inside a facial prominence.".
- 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 attached to your class form or handed in, and confirmed.
What's next: The face-building cells are born at the top of the , near the brain, and break free by . But the prominences they need to fill sit far away around the mouth and jaw. So the next question is: how do these cells travel from the neural folds to the right facial blocks? We chase that next time.