Clue 1: Orient yourself
Does a storm delay every flight?
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
Does a storm delay every flight?
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: An environmental factor changes risk only when evidence links dose, timing, and mechanism, and risk is not destiny.
On your WebXam
Applying critical-window timing to teratogen risk
For life
Turn the amount up and down; the result tells you if the signal decides or just allows.
Principle: Boss or doorman?
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
Weather changes the chance of a delayed flight
Airlines make decisions from wind, storms, visibility, and timing. Bad weather raises the chance of delay, but it does not delay every flight in the same way.
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
Why do timing and severity matter?
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 separates association from a tested mechanism?
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.
- 1Does a storm delay every flight?
- 2Why do timing and severity matter?
- 3What evidence separates association from a tested mechanism?
Tier 1 check
Finish with the everyday model
Use the everyday picture to answer today's question in plain words: Does a storm delay every flight?
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 risk factor changes probability, not certainty.
Rule 2: Dose and timing shape the effect.
Rule 3: Association, animal mechanism, and human causation are different evidence levels.
Where the analogy stops: Embryonic development is not air travel, and personal blame has no place in risk interpretation.
Carry the previous idea forward
A developmental risk matters most when it acts during the short window for the process it can disrupt.
Today's technical takeaway
An environmental factor changes risk only when evidence links dose, timing, and mechanism, and risk is not destiny.
Now map the same rules onto biology
Grade evidence for folate, valproate, and other exposures
Weather report
Observed association
Storm intensity and arrival
Dose and critical-window timing
Flight mechanics
Tested cellular or molecular mechanism
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
DEV16-E1
Some prenatal exposures are associated with higher cleft risk in populations.
Why it matters: Association can identify a factor worth studying.
DEV16-E2
Valproate is a known teratogenic medication whose risks depend on exposure context and timing.
Why it matters: A specific factor can have biologically important prenatal effects.
DEV16-E3
Most exposed pregnancies do not produce the same outcome, and many clefts occur without a known exposure.
Why it matters: Risk is probabilistic and multifactorial.
Make the clinical decision
You are writing a family-facing explanation for Mateo's chart.
A parent asks whether one action definitely caused the cleft, but the case file contains no confirmed causal exposure.
AExplain that risk factors change probability and no single cause is established here.
BAssign blame without exposure evidence.
CSay environmental factors can never affect development.
Choose the explanation and cite evidence about probability and case limits.
Evidence required
DEV16-E1 + DEV16-E2 Claim ceiling
You may explain population risk and biological plausibility. You may not assign an unrecorded exposure or blame.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 16: When the Outside World Reaches the Embryo
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
- The lip closes (medial nasal plus maxillary ) during human weeks 4 to 6.
- The secondary grows, elevates, and fuses during human weeks 6 to 12, with complete by about week 12.
If not, review
Today's new idea is only
Environmental exposures such as low , smoking, and valproate raise or lower the probability that succeeds during the window; they are risk-modifiers, not single causes.
Goal: Explain how environmental exposures ( status, smoking, valproate) change the probability that lip and succeeds, and rank them as risk-modifiers rather than single causes.
Know by the end
- A teratogen is an environmental agent that can disturb normal development, but only if it acts during the structure's critical window.
- Low maternal is studied as a modifiable ; the protective size for clefts is debated and weaker than for neural-tube defects.
- Maternal smoking is a repeatedly reported association for orofacial clefts, with the mechanism still being worked out.
- Most exposures raise or lower the probability of a rather than guaranteeing one, which is why we say not cause.
1
What a teratogen is
Model start: A teratogen is an environmental agent (a drug, chemical, infection, or deficiency) that can disturb normal development of an , but only if it acts during that structure's critical window.
- supplies methyl groups used to build and regulate DNA; low maternal folate is studied as a ____ (modifiable) , with a debated protective size for clefts.
- Maternal smoking is a repeatedly reported ____ (association) for orofacial clefts.
2
Risk, not destiny
- Valproate belongs to a drug class studied as a teratogenic ____ (risk) factor for birth defects including clefts.
- Most exposures ____ (raise or lower) the probability of a rather than guaranteeing one, which is why we say , not cause.
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: Environmental exposures such as low , smoking, and valproate raise or lower the probability that succeeds during the window; they are risk-modifiers, not single causes.
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 · PLTW PBS 072110
WebXam domain
Molecular and Genetic Technology
Evidence to produce
Write a one-paragraph teratology note for Mateo's chart. State: (1) which of the three exposures, if present, could plausibly have acted during his fusion window, (2) why you would still NOT call any single exposure the cause, and (3) one prevention message for a future pregnancy. Flag every uncertainty honestly, the way the sources do.
Lab / skill
Principles of Biomedical Science (PBS)
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 outside world (can / cannot) change whether Mateo's lip and fuse.
- Evidence: One exposure and what the literature says about its strength.
- Reasoning: Why timing within the critical window decides whether an exposure matters, and why we say not cause.
How this is graded (rubric)
For: Write a one-paragraph teratology note for Mateo's chart. State: (1) which of the three exposures, if present, could plausibly have acted during his fusion window, (2) why you would still NOT call any single exposure the cause, and (3) one prevention message for a future pregnancy. Flag every uncertainty honestly, the way the sources do.
| 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 "Write a one-paragraph teratology note for Mateo's chart. State: (1) which of the three exposures, if present, could plausibly have acted during his fusion window, (2) why you would still NOT call any single exposure the cause, and (3) one prevention message for a future pregnancy. Flag every uncertainty honestly, the way the sources do.".
- 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: Yes, the environment can tip the odds during the window. But here is the puzzle: the same exposure can reach two embryos with the same DNA and only one of them clefts. How can identical DNA give different results?