WHAT THIS MODEL HELPS US SEE
The visible method sequence links cell structures to separation techniques and makes observation-versus-inference explicit.
LAUNCH · GCSE Biology · Lesson 15 of 18 · DoLAUNCH · GCSE Biology · Week 12 · Do
Fruit DNA: Extract, Observe, Evaluate
Sequence outcome: Explain how DNA can be extracted from fruit; connect the observation to genetic information.
🎯 Learning objective: I can explain the steps in fruit-DNA extraction, record an observation and evaluate the evidence cautiously.
✅ Success criteria
- I can order the extraction method and explain the role of detergent, salt, filtration and cold ethanol.
- I can record the precipitate observation without calling it pure DNA.
- I can connect extracted DNA to chromosomes and genes and state a method limitation.
Arrival · previous learningStarter · observe / predictI Do · model the reasoningWe Do · hinge & responseI Do 2 · connect / extendWe Do 2 · scientific model / dataIndependent · evidence & transferExit · receive and use the response
🧪 Non-Core Evidence Lab: follow the method, observe precipitate and limit the claim.⏱ 40 minutes📍 C42 only🔁 Live Lundy loop↺ Retry without penalty
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
⏱ 3 min
🚪 Arrival · previous learningRetrieve only what has already been taught
- W12L2: DNA has two complementary strands coiled into a double helix.
- W12L1: chromosomes contain DNA and genes are sections of DNA.
- W5: a method needs controlled handling and honest evaluation.
- Lead-in: why would a white precipitate not prove that a sample is pure DNA?
New to this class, absent, or not sure? Everything needed is in the retrieval box above. Read it, point to it or ask a familiar adult to read it exactly.
◆ Supported
- Match A with T.
- Complete: a gene is a section of __.
- Point to FILTER for separating liquid from fruit pieces.
- Lead-in: choose observe or prove for seeing a white precipitate.
▲ Standard
- Describe complementary base pairing.
- State the chromosome-DNA-gene relationship.
- Explain what filtration separates.
- Lead-in: why is observation different from identification?
★ Stretch
- Evaluate one limit of the DNA model.
- Explain why extracting DNA does not reveal its base sequence.
- Distinguish precipitate from a pure substance claim.
- Lead-in: identify one control needed for a fair yield comparison.
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.
🔊 Read-aloud route: a familiar adult may read the task exactly while the text remains visible. No device voice or media permission is required.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
⏱ 3 min
🌱 Starter · observe / predictWhite stringy material appears where the fruit filtrate meets cold ethanol. What is the safest scientific claim?
LOCAL VISUAL HOOK · FRAME 1
RELEASE · disrupt membranes
Get the DNA out of the cells.
LOCAL VISUAL HOOK · FRAME 2
SEPARATE · filter solids
Keep the liquid.
LOCAL VISUAL HOOK · FRAME 3
PRECIPITATE · cold ethanol
Adult adds ice-cold ethanol slowly. DNA is insoluble in it, so it comes out of solution.
Commit one first idea. Predictions are held, not marked. Pointing, selecting, saying or signing all count.
Choose one idea. The lesson will test it; nothing is scored or saved.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
⏱ 4 min
👩🏫 I Do · model the reasoningMake the first scientific idea visible
FILTRATEliquid through the filterthe liquid that passes through filter paper or mesh
PRECIPITATEmaterial appearing from solutiona substance that forms as a visible solid from a solution
EXTRACTremove from a mixtureto separate a substance from material containing it
WHAT THIS MODEL DOES NOT SHOW
The precipitate is not purified DNA, yield is not measured accurately by appearance and the activity cannot show a gene, base pair or double helix directly.
Step 1
Mash the fruit with salt-detergent solution: detergent disrupts cell and nuclear membranes, while salt helps DNA strands clump together.
Step 2
Filter the mixture; collect the filtrate while larger fruit solids remain behind.
Step 3
An adult slowly adds ice-cold ethanol. With salt present, DNA is insoluble in the ethanol and precipitates as DNA-containing material; record any white/stringy precipitate without claiming purity.
Word help keeps the scientific term visible and adds a plain-language bridge.
🍓 Extraction sequencer + cautious evaluation
Order: —
Which conclusion is cautious enough?
Say what you saw, then what it is consistent with.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
⏱ 4 min
🤝 We Do · hinge & responseWhy is detergent used in this extraction?
Everyone commits before explanation.
Use a button, point, say/sign or let an adult operate the chosen button. A retry is information, not a penalty.
Choose one response, then use the model to explain or retry.
Audience move: the adult names back the Science heard or seen, without upgrading the pupil’s words.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
⏱ 3 min
👩🏫 I Do 2 · connect / extendConnect the model to the second idea
Connection: the model is useful when its visible pattern is translated into a scientific explanation.
Connection 1
Observation: describe colour, location and texture without writing 'pure DNA'.
Connection 2
Inference: the extraction method is expected to produce DNA-containing material, but appearance alone cannot identify every component.
Connection 3
Connection: the extracted DNA came from fruit-cell chromosomes and contains many genes; the extraction does not reveal individual genes or base sequence.
MODEL STRENGTH
The visible method sequence links cell structures to separation techniques and makes observation-versus-inference explicit.
MODEL LIMIT
The precipitate is not purified DNA, yield is not measured accurately by appearance and the activity cannot show a gene, base pair or double helix directly.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
⏱ 4 min
🤝 We Do 2 · scientific model / dataObservation, inference or limitation?
Classify each statement after the practical or parity dataset, then repair any overclaim.
METHODOBSERVEINFERLIMITCONNECT
Cards to place
Matching groups
No claim classified. Preserve the observation before interpreting it.
🧩 Science glitch · find and repair it
Claim: The white material proves that a pure gene has been seen.
The incorrect idea is shown as a challenge, never as teaching.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
⏱ 15 min
✏️ Independent · evidence & transferCarry out or direct the non-core fruit-DNA extraction, record the result and evaluate the evidence.
👐 Physical route
Adult-prepared fruit, salt-detergent solution, sealable bag, filter/mesh, clear tube, cold ethanol controlled by an adult, tray and observation sheet.
Same outcome: I can explain the steps in fruit-DNA extraction, record an observation and evaluate the evidence cautiously.
🖥 Offline digital / director route
Use the included method sequence and parity observations from a successful and weak extraction; classify observation, inference and limitation.
Same evidence: An ordered method, precise observation, DNA/chromosome/gene connection and one valid evaluation point.
🧰 Equipment / setupAdult-prepared fruit, salt-detergent solution, sealable bag, filter/mesh, clear tube, cold ethanol controlled by an adult, tray and observation sheet.
🛡 Safety / sensoryLocal risk assessment required. Ethanol is flammable and adult-handled only; keep away from flames/heat. Wear eye protection as locally required. Do not taste or touch materials; wash hands and clear spills promptly.
🖥 Offline parityUse the included method sequence and parity observations from a successful and weak extraction; classify observation, inference and limitation.
No-equipment/access route: The pupil directs each method step while an adult handles all liquids, or analyses the parity dataset. Direction, observation and evaluation remain the assessed Science.
◆ Supported
Order four method pictures, select the observed result and complete one limitation sentence.
Scaffold
Use release, filter, precipitate and not pure. An adult handles all materials.
▲ Standard
Record method and observation, explain two reagent/separation roles and evaluate one limitation.
Scaffold
Use Observation → Inference → Limitation headings.
★ Stretch
Compare practical/parity outcomes, identify variables that affect visible yield and propose one fair improvement.
Scaffold
Do not claim molecular identity or purity; no Higher-tier analytical chemistry is needed.
Evidence gate
1 · Pupil decisionPrediction, question, method or choice is visible.
2 · Observable evidenceA result, source note, model state or adult observation is preserved.
3 · Pupil meaningAn ordered method, precise observation, DNA/chromosome/gene connection and one valid evaluation point.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
⏱ 4 min
🎫 Exit · receive and use the responseFinish with an edit or re-attempt on the existing work
Supported
What does detergent help release from cells?
Standard
Why is 'DNA-containing precipitate' better than 'pure DNA'?
Stretch
Explain why this extraction cannot show an individual gene or DNA base sequence.
Adult Audience
The familiar adult genuinely receives the pupil response, then says back the Science they heard or saw. The adult does not add a score or rewrite the pupil.
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting
Receive the pupil’s Voice, complete real Audience, then choose what changes.
Session state is temporary. Reload clears responses; there is no account, upload or saved pupil identity.
QUESTIONEVIDENCEPATTERNEXPLANATIONAPPLICATIONEVALUATION
LAUNCH rule: explanation is earned through prediction, observation, measurement, calculation or reasoning from evidence.
🛡 SPACE
🗣 VOICE
👂 AUDIENCE
⚙ INFLUENCE
SPACE available · VOICE waiting · AUDIENCE waiting · INFLUENCE waiting