LAUNCH · GCSE Biology · Week 4 · Do
Diffusion Explanation & Exam Lab
🎯 Learning objective: I can construct GCSE diffusion explanations linking direction, gradient and adaptations.
✅ Success criteria
- Respond to the command word.
- Use cause-and-effect rather than repeating the question.
- Transfer diffusion to unfamiliar contexts.
ArrivalStarterI DoWe DoI Do 2We Do 2IndependentExit
🧬 Edexcel GCSE Biology 1BI0 Foundation · Paper 1 · Topic 1🧪 Explain Like a Biologist⏱ 40 minutes
🫁
Do → Explain Like a Biologistobserve · predict · test · explain · applyQUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
Stable conditions and clear expectations make GCSE thinking possible.
⏱ 3 min
🚪 Arrival · previous learningRetrieve the previous learning: W4L1–2 definition, factors, gas exchange and evidence.
Not here last lesson? Everything you need is in the box above — read it, then answer.
◆ Supported — three retrieval questions and one lead-in
R1 Last lesson
Point to the air sac on the diagram.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Standard — Last lesson you applied diffusion to the lungs. Name one adaptation and what it does.
R2 Week 4 · lesson 1
Say which way particles move overall in diffusion.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Standard — Week 4: define diffusion using the words net movement and gradient.
R3 Week 3
Point to something too small to see without a microscope.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Standard — Week 3: why are cells measured in micrometres?
Lead-in Into today
Today you write the explanation. Point to the first sentence starter.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Standard — Today you build a full explanation. What has to be in it besides the word diffusion?
▲ Standard — three retrieval questions and one lead-in
R1 Last lesson
Last lesson you applied diffusion to the lungs. Name one adaptation and what it does.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Stretch — Last lesson: explain how three alveolar adaptations act together on the rate.
R2 Week 4 · lesson 1
Week 4: define diffusion using the words net movement and gradient.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Stretch — Week 4: explain why diffusion needs no energy from the cell.
R3 Week 3
Week 3: why are cells measured in micrometres?
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Stretch — Week 3: explain why small size and short distances matter for exchange.
Lead-in Into today
Today you build a full explanation. What has to be in it besides the word diffusion?
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Stretch — An explanation that names a process but never links it to evidence is incomplete. Say what is missing.
★ Stretch — three retrieval questions and one lead-in
R1 Last lesson
Last lesson: explain how three alveolar adaptations act together on the rate.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Supported — Point to the air sac on the diagram.
R2 Week 4 · lesson 1
Week 4: explain why diffusion needs no energy from the cell.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Supported — Say which way particles move overall in diffusion.
R3 Week 3
Week 3: explain why small size and short distances matter for exchange.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Supported — Point to something too small to see without a microscope.
Lead-in Into today
An explanation that names a process but never links it to evidence is incomplete. Say what is missing.
Non-reading route: point to it, say it, or show it. An adult can scribe your exact words. Next step up: Supported — Today you write the explanation. Point to the first sentence starter.
Arrival retrieves three times, then leads in. R1 is last lesson, R2 is earlier this week, R3 is older material, and the lead-in opens today without teaching today’s concept.
LAUNCH response routes
📝 write / edit🗣 structured verbal📏 measure / calculate📊 graph / interpret🧪 practical / demonstrate🔁 re-attempt
Access changes the response route, not the GCSE Biology entitlement.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
Quiet retrieval before new demand; uncertainty is information, not public failure.
⏱ 3 min
🌱 Starter · observe / predict🔍 Scientific question
‘Explain why oxygen enters blood quickly.’ Why is ‘It diffuses’ not enough?
FRAME 1/4
READ COMMAND WORD
Pause for observation or prediction before advancing.
FRAME 2/4
BUILD CAUSAL CHAIN
Pause for observation or prediction before advancing.
FRAME 3/4
COMPARE WITH MODEL
Pause for observation or prediction before advancing.
FRAME 4/4
EDIT ONE SCIENTIFIC LINK
Pause for observation or prediction before advancing.
🎯 Commit to a prediction
Before you write: what turns a description into an explanation?
Choose one. Say it, point to it, or press it.
Nothing here is right or wrong yet, and nothing is marked, scored or stored. A prediction is still worth having when it turns out differently — that is what makes the test worth running.
LAUNCH response routes
📝 write / edit🗣 structured verbal📏 measure / calculate📊 graph / interpret🧪 practical / demonstrate🔁 re-attempt
Access changes the response route, not the GCSE Biology entitlement.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
Prediction/observation precedes explanation.
⏱ 4 min
👩🏫 I Do · model the reasoning🧠 Teacher reasoning model — reveal only after the class has observed/predicted.
STEP Separate DESCRIBE from EXPLAIN.
STEP Model concentration difference → diffusion → adaptation chain.
STEP Improve one weak answer by adding the missing causal link.
✔ What this model helps us seeIt shows the shape of a complete explanation: direction, then gradient, then adaptation.
✘ What this model does not showIt leaves out whether your own sentence actually links the parts — a frame can be filled in and still not explain anything.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
Teacher models scientific reasoning; staff watch access and the point where the idea lands.
⏱ 4 min
🤝 We Do · hinge & responseCommit before reveal: Which phrase most improves an explain answer?
Answer first. The reveal is earned by the response, not by a timer.
LAUNCH response routes
📝 write / edit🗣 structured verbal📏 measure / calculate📊 graph / interpret🧪 practical / demonstrate🔁 re-attempt
Access changes the response route, not the GCSE Biology entitlement.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
Adult genuinely receives the response; the next question, explanation or scaffold changes because of it.
⏱ 3 min
👩🏫 I Do 2 · connect / extend🧠 Teacher reasoning model — reveal only after the class has observed/predicted.
STEP Apply diffusion to a new context.
STEP Use feedback as an edit, not a full rewrite.
STEP Model answers show precision and shape, not grades.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
Teacher models scientific reasoning; staff watch access and the point where the idea lands.
⏱ 4 min
🤝 We Do 2 · scientific model / dataInteractive reasoning: predict/observe first → use the model → explain the evidence → adult receives it.
🧭 Command-word decoder
DESCRIBEwhat / pattern
EXPLAINwhy / causal link
CALCULATEworking + answer
COMPAREboth sides
Pick a Topic 1 idea and say how the answer shape changes under each command word.
🧱 Explanation chain lab
The decoder above shows what EXPLAIN demands. This lab is button-only. One question — explain why oxygen moves from the alveolus into the blood — and three candidate sentences, each frozen with what it contributes.
Step 1 · Predict, before you test
Which sentence should an EXPLAIN answer be built around?
Choose one. Say it, point to it, or press it. Nothing here is right or wrong yet.
Step 2 · Test each sentence
Press one to test it.
Frozen results — these stay on the page
Nothing tested yet.
Step 3 · Explain
SCIENCE GLITCH: “The oxygen spreads out because it wants to reach the blood.”
Use your frozen list as the evidence. Decide, then say why.
Every step is a button, and each option carries a shape and a word as well as its colour. Say it, point to it or have an adult press it — the route does not change the Biology.
LAUNCH response routes
📝 write / edit🗣 structured verbal📏 measure / calculate📊 graph / interpret🧪 practical / demonstrate🔁 re-attempt
Access changes the response route, not the GCSE Biology entitlement.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
Adult genuinely receives the response; the next question, explanation or scaffold changes because of it.
⏱ 15 min
✏️ Independent · evidence & transfer✏️ Independent GCSE Biology
Answer the mixed questions. Some say describe. Some say explain. Some say apply. Pick one answer. Read the model. Compare the two. Make one clear edit. Say why it improved.
🧪 PRACTICAL / EVIDENCE READY
EquipmentQuestion set; model-answer reveals; diffusion/alveolus diagrams.
Safety / accessNo practical hazard; reduced question count can preserve same explanation demand.
Evidence targetIndependent answers + one self-edit/re-attempt + adult Audience.
15 minutes. Supported / Standard / Stretch are movable routes, not grade identities.
◆ Four questions. Each has a prompt. It names the command word.
What happens? → why? → factor/adaptation.
Fade: remove the first prompt that no longer changes success.
▲ Six mixed questions. One is new. It uses a new context.
Highlight the command word. Then the technical terms.
Fade: remove the first prompt that no longer changes success.
★ Six questions. Then one more. Evaluate a damaged exchange surface.
Be precise. Extra detail is off the point. It does not help.
Fade: remove the first prompt that no longer changes success.
1 · Learner decisionprediction, plan, command-word choice or calculation set-up
2 · Observable Sciencemeasurement, graph, working, model, practical result or answer
3 · Learner responseexplanation, evaluation, edit or re-attempt after feedback
📖 WORD HELP
explainsay how or why, linking cause to effect
diffusionspreading out from where there is more to where there is less
evidencethe observation or data your claim rests on
Use the Biology word first. Ask for help only when you need it. TA fade route: model the word. Then prompt for it. Then wait for it. Drop a step as soon as the pupil no longer needs it.
LAUNCH response routes
📝 write / edit🗣 structured verbal📏 measure / calculate📊 graph / interpret🧪 practical / demonstrate🔁 re-attempt
Access changes the response route, not the GCSE Biology entitlement.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
Pupil reasoning stays attributable; feedback produces an edit, re-attempt, calculation, explanation or application.
⏱ 4 min
🎫 Exit · receive and use the response◆ Supported
What does explain need that describe does not?
▲ Standard
Give one causal O₂ diffusion sentence.
★ Stretch
Explain effect of reduced surface area.
🔁 LAUNCH Lundy close — use the existing work
1) Pupil answers / edits / re-attempts. 2) Adult genuinely reads, listens or watches and names back what was received. 3) Where appropriate, the pupil adds the single response/next-step line on the same work: “I changed / next I will …”
No adult signature/countersignature. If local policy uses R, it follows genuine Audience only; this page never adds it automatically.
Closing the loop: this one ends on paper — your own hand, or your words scribed by an adult. Saying it aloud starts the loop; writing it is what closes it. Pass is always allowed.
What I said, and what it changed:
LAUNCH response routes
📝 write / edit🗣 structured verbal📏 measure / calculate📊 graph / interpret🧪 practical / demonstrate🔁 re-attempt
Access changes the response route, not the GCSE Biology entitlement.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: the explanation is earned by observation, prediction, measurement, testing or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
LAUNCH response stays on the existing work; adult genuinely receives it, then the next learning move changes.