Rough draft.This research track is under review with Dr. Atit's lab. Content and sequence may still change.
Craniofacial Research Track
Session 5The Master Switch, OctoberLens: Human Body Systems
The master switch: how a cell chooses its fate
Discovery question
Two sit side by side in Mateo's . One becomes bone, the other becomes . What flips the switch that sends them down different paths?
A cell's fate is set by the genes it turns on. factors and signals like Wnt act as a master switch that commits a cell to one program, such as bone, rather than another.
The plan
Prerequisite check
Before this page, you should know
- Cranial form at the edges (folds) of the early , then migrate away into the head.
- In the face these cells become : the bone, , and that fill the prominences.
If not, review
Today's new idea is only
A cell's fate is set by the genes it turns on. factors and signals like Wnt act as a master switch that commits a cell to one program, such as bone, rather than another.
Learn first
What to learn
Goal: Explain cell fate as a gene-expression decision and describe how a master-switch and Wnt signaling commit a to bone or .
Know by the end
- Cell fate is the final identity a cell commits to, set by which genes it switches on.
- A is a that binds DNA and turns specific genes on or off.
- A master switch is a or signal that flips a cell into one whole fate program at once.
- Wnt signaling is a cell-to-cell pathway that helps decide fate and pushes cells toward making skull and facial bone.
- is the result: an unspecialized cell becomes a specialized one, such as a bone-forming cell.
The plan
Guided notes
1
What fate means
Model start: Cell fate is the identity a cell settles into, decided not by changing its DNA but by which genes it turns on.
- Define cell fate in your own words, using the idea of genes turning on.
- Explain how two cells with the same DNA can end up as different cell types.
2
The switch and the signal
Model start: A lands on DNA and acts like a switch, turning a set of genes on or off together.
- Describe what a does to a gene.
- Using the Atit-lab idea, explain how Wnt signaling can tip a toward becoming bone.
3
Why this matters for a cleft
Model start: If the bone program never fully switches on, the makes too little bone and stays too small to reach the .
- Predict what could go wrong if the master switch for bone fires too weakly in a .
- Connect the decision a single cell makes to whether Mateo's grows enough to fuse.
Explore
Reading the Research
What to read
Read the title and the abstract only, not the whole paper. Dr. Atit's published craniofacial research (PubMed)
Why this source matters
This is the published evidence behind today's idea: A cell's fate is set by the genes it turns on. factors and signals like Wnt act as a master switch that commits a cell to one program, such as bone, rather than another.
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.
Explore
Vetted links for this session
Learn first
Pick your level
Level 1, Guided
Use the sentence starters, a word bank from the vocabulary, a labeled diagram, and the exact source link.
Level 2, Collaborative
Complete a partly blank model or table and explain it.
Level 3, Independent
Make a claim from a new example or an unfamiliar entry in the same database.
The plan
Work as a research team
Team roles
- Manager: keeps the group moving
- Recorder: writes the shared model or table
- Evidence checker: verifies each claim against the source
- Reporter: explains the group's reasoning
Process reflection
- What evidence changed your thinking today?
- What did your group disagree about, and how did you resolve it?
- What question is still unresolved?
Check yourself
Demonstration of learning
By the end of this session, submit ONE of: a labeled diagram with a 2-sentence explanation; a claim, evidence, reasoning paragraph; a completed data table from a real database; or a one-question exit ticket using today's vocabulary.
Meets standard if your explanation correctly connects structure, timing, gene or protein function, or evidence source to Mateo's case: Explain cell fate as a gene-expression decision and describe how a master-switch transcription factor and Wnt signaling commit a neural crest cell to bone or cartilage.
How this is graded (rubric)
For: Explain cell fate as a gene-expression decision and describe how a master-switch transcription factor and Wnt signaling commit a neural crest cell to bone or cartilage.
| 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 "Explain cell fate as a gene-expression decision and describe how a master-switch transcription factor and Wnt signaling commit a neural crest cell to bone or cartilage.".
- 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.