Clue 1: Orient yourself
What must happen before the zipper can close?
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 must happen before the zipper can close?
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: Upper-lip closure requires growth, contact, and stable fusion at the maxillary-medial nasal boundary.
On your WebXam
Explaining why cleft lip and cleft of the front palate often occur together
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
Two zipper halves must align before they close
A zipper joins two separate edges. The teeth must face each other, line up, and enter the slider before the seam can close.
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
How could alignment fail even if both halves exist?
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
What evidence would separate missing material from failed closure?
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 must happen before the zipper can close?
- 2How could alignment fail even if both halves exist?
- 3What evidence would separate missing material from failed closure?
Tier 1 check
Finish with the everyday model
Use the everyday picture to answer today's question in plain words: What must happen before the zipper can close?
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: Parts must first grow into range.
Rule 2: Correct contact must precede stable joining.
Rule 3: A gap can result from failure at more than one step.
Where the analogy stops: Tissues remodel and fuse through cell behavior, not metal teeth.
Carry the previous idea forward
Face-building cells must travel in organized streams to the right destination before they can build the right structure.
Today's technical takeaway
Upper-lip closure requires growth, contact, and stable fusion at the maxillary-medial nasal boundary.
Now map the same rules onto biology
Name the three steps in upper-lip closure
Bring zipper halves together
Prominence growth
Align the teeth
Correct tissue contact
Pull the slider
Stable epithelial remodeling and fusion
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
DEV05-E1
Upper-lip tissues must grow into contact during the early facial window.
Why it matters: Distance is a developmental variable.
DEV05-E2
The maxillary prominence meets the medial nasal region at the lip boundary.
Why it matters: The contact must occur at the correct neighbor.
DEV05-E3
The joined surface must remodel into continuous tissue.
Why it matters: Touching alone is not the completed lip.
Make the clinical decision
You are annotating a developmental animation for the family conference.
The animation shows both tissue blocks present but never making stable contact on the left.
ALabel a failed growth/contact/fusion sequence at the left lip boundary.
BLabel a secondary palate elevation failure only.
CClaim the tissue blocks were never present.
Choose the label that fits the animation and cite the boundary evidence.
Evidence required
DEV05-E1 + DEV05-E2 Claim ceiling
You may identify the failed morphologic sequence. You may not identify a gene from the animation alone.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 5: How and When Does the Upper Lip Close?
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
- After , cranial travel in organized migratory streams, each with a destination, not at random.
- The front of the face is filled by cells that migrate into the and the first pharyngeal arch, which becomes the maxillary and mandibular processes.
Today's new idea is only
The upper lip closes at about weeks 4 to 6 when the medial nasal and maxillary processes fuse, and that same seeds the front of the , so a lip failure often extends backward.
Goal: Explain that the upper lip closes when the medial nasal, lateral nasal, and maxillary prominences merge and fuse at about human weeks 4 to 6, forming the upper lip, , and primary , and identify this as the step that fails in a lip.
Know by the end
- The two medial nasal processes merge into the , which becomes the , the four upper incisors, and the primary .
- The upper lip closes at about human weeks 4 to 6 when each fuses with the medial nasal block beside it.
- When the medial nasal and maxillary processes fail to fuse, the upper lip does not close, producing a lip that can be or .
- Because the same seeds the primary , lip with cleft palate is treated as one developmental group.
1
How and when the lip closes
Model start: The upper lip closes by at about human weeks 4 to 6, when the two medial nasal processes merge into the and the on each side fuses to the medial nasal block beside it.
- The becomes the , the four upper ____ (incisors), and the primary .
- The primary sits to the ____ foramen.
2
When fusion fails
- When the medial nasal and ____ processes fail to fuse, the upper lip does not close (a lip).
- Because the same seeds the primary , lip with cleft palate is one developmental ____.
3
An honesty note
- We now know which failed on Mateo's left side and roughly when, but we do not yet know ____ it failed.
- We also notice the rest of his body checked out normal, a clue we keep but do not yet turn into a ____.
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: The upper lip closes at about weeks 4 to 6 when the medial nasal and maxillary processes fuse, and that same seeds the front of the , so a lip failure often extends backward.
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 · Tissue fusion and the formation of the lip and primary palate
WebXam domain
Molecular and Genetic Technology
Evidence to produce
On a labeled front-view diagram of the developing upper lip, outline the medial nasal blocks (intermaxillary segment) in one color and the maxillary processes in another. Draw the LEFT fusion line that did not seal for Mateo and the RIGHT line that did, then finish: "Mateo's upper lip is open on the left because the ____ and ____ processes did not fuse there at about week 4 to 6."
Lab / skill
Principles of Biomedical Science (PBS) · Human Body Systems (HBS)
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.
- Claim: The upper lip closes when the medial nasal and maxillary processes fuse, at about human weeks 4 to 6.
- Evidence: The two medial nasal processes merge into the ____ segment, and each fuses to the medial nasal block beside it; failure here is a ____ lip.
- Reasoning: Because that same also seeds the primary , a left-side failure in Mateo can leave both the lip and the front of the palate open on that side, which matches his chart.
How this is graded (rubric)
For: On a labeled front-view diagram of the developing upper lip, outline the medial nasal blocks (intermaxillary segment) in one color and the maxillary processes in another. Draw the LEFT fusion line that did not seal for Mateo and the RIGHT line that did, then finish: "Mateo's upper lip is open on the left because the ____ and ____ processes did not fuse there at about week 4 to 6."
| 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 "On a labeled front-view diagram of the developing upper lip, outline the medial nasal blocks (intermaxillary segment) in one color and the maxillary processes in another. Draw the LEFT fusion line that did not seal for Mateo and the RIGHT line that did, then finish: "Mateo's upper lip is open on the left because the ____ and ____ processes did not fuse there at about week 4 to 6."".
- 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 upper lip closes at about weeks 4 to 6, forming the lip and the small front triangle of . But that triangle is only the front of the roof of the mouth. Behind the , the palate is still wide open. So the next question is: how does the palate begin? We chase that next time.