Clue 1: Orient yourself
What are the main parts, stages, or choices in this model?
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
Two cells carry the same instructions. Why does one build hard tissue while the other builds flexible support?
Why it matters: Gene switches create normal cell identities from one shared genome. Cancer can misuse the same controls over growth and identity, so this lesson connects development, diagnosis, and treatment research.
On your WebXam
You can explain how cells with the same DNA become different by switching different genes on.
For life
Having a gene is not the same as using it.
Principle: Having it is not using it
Try the everyday version first
Having it is not using it
Two rooms have the same breaker panel. One room powers bright lights while the other powers a fan because different switches are on.
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 while the other parts stay the same?
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 check would separate two explanations that still fit the picture?
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 are the main parts, stages, or choices in this model?
- 2What changes while the other parts stay the same?
- 3What check would separate two explanations that still fit the picture?
Tier 1 check
Finish with the everyday model
Use the breaker panels to explain how two builders with the same instructions can make different materials.
Answer in plain words. You can finish this required check without opening either optional section below.
Ready for the real names? Optional tier 2
Craniofacial Research Track
Session 5The Master Switch, OctoberLens: Human Body Systems
The master switch: how a cell chooses its fate
Discovery question
Two cells carry the same instructions. Why does one build hard while the other builds flexible support?
Having it is not using it. Cells can carry the same full set of instructions and still do different jobs because they switch on different parts.
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
Having it is not using it. Cells can carry the same full set of instructions and still do different jobs because they switch on different parts.
Goal: Use the switch-panel model to explain how two cells with the same instructions can build different tissues.
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.
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.
MedlinePlus
Open the tool Plain-language explanations of a gene or condition, written for patients and families.
When you use this: Use this when a research paper is too dense, or when you need to explain a finding to Mateo's family in everyday words.
What the screen looks like
Step by step
- 1Open medlineplus.gov/genetics and search the gene or condition (IRF6).
- 2Read the summary written in everyday words.
- 3Note the conditions the gene is linked to at the bottom of the page.
Capture these fields
- Topic: IRF6 gene
- Plain-language summary: IRF6 helps the tissues of the face join correctly before birth.
- Linked conditions: Van der Woude syndrome; nonsyndromic cleft
How to read it: Start here when a research paper is too dense. MedlinePlus gives you the gist in everyday words so you can go back to the harder source knowing what it is about.
Lost? About MedlinePlus Genetics
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.
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?
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: Use the switch-panel model to explain how two cells with the same instructions can build different tissues.
How this is graded (rubric)
For: Use the switch-panel model to explain how two cells with the same instructions can build different tissues.
| 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 "Use the switch-panel model to explain how two cells with the same instructions can build different tissues.".
- 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.
Go deeper Optional tier 3
Everything required is above. Open this section only if you want the research reading and source trail.
Student reading
The idea in plain English
Two cells carry the same instructions. Why does one build hard while the other builds flexible support?
Two rooms have the same breaker panel. One room powers bright lights while the other powers a fan because different switches are on.
Having it is not using it. Cells can carry the same full set of instructions and still do different jobs because they switch on different parts.
- 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.
This lesson reading is written from the vetted sources in the advanced citation trail below.
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 reading for this session
Why this source matters
This explanation gives you the background for today's idea without making you decode a research paper: Having it is not using it. Cells can carry the same full set of instructions and still do different jobs because they switch on different parts.
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.
These records and papers document the science. They are not assigned student reading. Use the plain-language lesson reading above unless your teacher asks you to inspect an original source.