1. Difference
A sample grows from 1.8 mm to 2.4 mm. What is the increase?
Help beside the question
Read or point first. After minus before.
Answer guidance
0.6 mm.
Growth data: evidence before claims
Learning objective
Calculate changes and interpret growth or stem-cell data without turning a pattern into a diagnosis or cure claim.
40 minutes · one route · start from what you show today. Point, speak, sign, draw, write or direct an adult. An adult may read or scribe your exact words. Choose one route; do not complete all three.
LAUNCH · GCSE BIOLOGY FOUNDATION · W10 · LESSON 3 · 4 MINUTES
Four clues to start
Supported · 4 questions
2. Percentage
80 out of 100 cells show a marker. What percentage is this?
Help beside the question
Read or point first. Out of 100 means percent.
Answer guidance
80%.
3. Measure
Does a marker alone prove a cell is working normally?
Help beside the question
Read or point first. A label and a function are different kinds of evidence.
Answer guidance
No; a marker suggests identity but does not by itself prove normal function.
4. Growth chart
What does the 50th percentile describe?
Help beside the question
Read or point first. Compare a measurement with a reference group.
Answer guidance
About half the reference group is below and about half is above that value.
Standard · 4 questions
1. Difference
A sample grows from 1.8 mm to 2.4 mm. What is the increase?
Help beside the question
After minus before.
Answer guidance
0.6 mm.
2. Percentage
80 out of 100 cells show a marker. What percentage is this?
Help beside the question
Out of 100 means percent.
Answer guidance
80%.
3. Measure
Does a marker alone prove a cell is working normally?
Help beside the question
A label and a function are different kinds of evidence.
Answer guidance
No; a marker suggests identity but does not by itself prove normal function.
4. Growth chart
What does the 50th percentile describe?
Help beside the question
Compare a measurement with a reference group.
Answer guidance
About half the reference group is below and about half is above that value.
Stretch · 4 questions
1. Difference
A sample grows from 1.8 mm to 2.4 mm. What is the increase?
Help beside the question
After minus before.
Answer guidance
0.6 mm.
2. Percentage
80 out of 100 cells show a marker. What percentage is this?
Help beside the question
Out of 100 means percent.
Answer guidance
80%.
3. Measure
Does a marker alone prove a cell is working normally?
Help beside the question
A label and a function are different kinds of evidence.
Answer guidance
No; a marker suggests identity but does not by itself prove normal function.
4. Growth chart
What does the 50th percentile describe? Give a reason.
Help beside the question
Compare a measurement with a reference group.
Answer guidance
About half the reference group is below and about half is above that value. Accept a scientifically correct reason that uses the relevant model or evidence.
LAUNCH · GCSE BIOLOGY FOUNDATION · W10 · LESSON 3 · 4 MINUTES
Choose a first idea
80% of cultured cells carry a nerve-cell marker. Which claim fits?
Think or discuss first. No answer chosen yet.
LAUNCH · GCSE BIOLOGY FOUNDATION · W10 · LESSON 3 · 5 MINUTES
Watch the model
Mitosis increases cell number. New cells can grow before they divide again.
Worked explanation · reveal after thinking
Do not equate growth only with mitosis. Meristems are regions, not the name of every plant stem cell. Differentiation changes cell structure and gene activity; it does not normally remove the other genes.
32-second silent captioned explainer · optional
No sound or autoplay. Use instead of part of the modelling time, not as an extra activity.
Full transcript
More cells. Mitosis increases cell number. New cells can grow before they divide again.
Longer cells. Plant cells can elongate. A longer root is not proof that every cell has divided.
Different jobs. Differentiation produces cells with specialised structures, such as root hair cells or neurones.
Where growth begins. Meristems contain cells that keep dividing. New cells can elongate and differentiate.
LAUNCH · GCSE BIOLOGY FOUNDATION · W10 · LESSON 3 · 5 MINUTES
Sort using the evidence
Choose a card, then choose a group. Explain one placement using its clue.
Drag, or use Tab and Enter to select a card and its group. Pointing or adult-directed placement works too.
Directly supported
Possible interpretation
Overclaim
Choose a card first.
Read the card clues
The sample length rose by 0.6 mm: 2.4 − 1.8 = 0.6 mm.
80 of 100 cells carry a marker: This is the supplied count.
Division and growth may have contributed: Size alone cannot separate these processes.
The cells might be useful in further research: This is conditional, not a demonstrated treatment.
The marker guarantees a cure: Marker evidence is not clinical outcome evidence.
A single percentile diagnoses disease: One reference comparison is insufficient.
Would a small change help? · optional
Ask the lesson teacher for clearer labels, fewer cards, reading help, an adult-directed model or more thinking time. Your teacher will explain what can change, try it and check its effect. Ask privately or pass; no extra form is needed.
Group explanations · reveal after sorting
The sample length rose by 0.6 mm → Directly supported. 2.4 − 1.8 = 0.6 mm.
80 of 100 cells carry a marker → Directly supported. This is the supplied count.
Division and growth may have contributed → Possible interpretation. Size alone cannot separate these processes.
The cells might be useful in further research → Possible interpretation. This is conditional, not a demonstrated treatment.
The marker guarantees a cure → Overclaim. Marker evidence is not clinical outcome evidence.
A single percentile diagnoses disease → Overclaim. One reference comparison is insufficient.
LAUNCH · GCSE BIOLOGY FOUNDATION · W10 · LESSON 3 · 4 MINUTES
Work through one example
Worked example
A fictional tissue length rises from 2.0 to 2.5 mm. Calculate and qualify the change.
Step 1
Increase = 2.5 − 2.0 = 0.5 mm.
Step 2
Percentage increase = 0.5 ÷ 2.0 × 100 = 25%.
Step 3
The length measurement supports growth of the sample.
Step 4
It does not establish which cells divided or differentiated.
LAUNCH · GCSE BIOLOGY FOUNDATION · W10 · LESSON 3 · 4 MINUTES
Read a simulated growth chart
These values are fictional reference data, not a clinical chart. Plot the three percentile lines and Sample X. Describe the pattern without diagnosing.
| Time / months | 25th / cm | 50th / cm | 75th / cm | X / cm |
|---|---|---|---|---|
| 0 | 40 | 44 | 48 | 43 |
| 1 | 44 | 48 | 52 | 47 |
| 2 | 48 | 52 | 56 | 51 |
Reveal the plotted reference
Worked explanation · reveal after thinking
X increases by 8 cm overall and stays 1 cm below the simulated 50th-percentile line. It lies between the 25th and 50th lines. This fictional pattern cannot diagnose health.
LAUNCH · GCSE BIOLOGY FOUNDATION · W10 · LESSON 3 · 10 MINUTES
Show your understanding
Supported · choose one route
1. Plot
Plot Sample X and the three reference lines; label time and length.
For one line at a time, read month → length, mark each point, join carefully and label the line.
2. Calculate
Find the overall increase in X and the change 1.8→2.4 mm.
For each change, subtract start from finish. Record X: ___ cm; tissue: ___ mm.
3. Evaluate
Write one supported statement and one unjustified claim about the marker result.
Use two frames: the evidence shows ___. It does not yet show ___. Keep observation separate from interpretation.
Standard · choose one route
1. Plot
Plot Sample X and the three reference lines; label time and length.
Use the supplied axes sheet; point or direct an adult.
2. Calculate
Find the overall increase in X and the change 1.8→2.4 mm.
Keep the two datasets and their units separate.
3. Evaluate
Write one supported statement and one unjustified claim about the marker result.
Observation is not the same as function or cure.
Stretch · choose one route
1. Plot
Plot Sample X and the three reference lines; label time and length.
Use the supplied axes sheet; point or direct an adult.
2. Calculate
Find the overall increase in X and the change 1.8→2.4 mm.
Keep the two datasets and their units separate.
3. Extend the calculation
Calculate the percentage increase from 1.8 to 2.4 mm and state one limit.
Change ÷ original × 100.
LAUNCH · GCSE BIOLOGY FOUNDATION · W10 · LESSON 3 · 4 MINUTES
Two small checks
Supported · 2 questions
1. Calculate
A length increases from 1.8 to 2.4 mm. Give the change with its unit.
Help beside the question
Subtract the first value from the second. Write: working ___; answer ___; unit or percent ___.
Answer guidance
0.6 mm.
2. Qualify
Why is one point on a growth chart not a diagnosis?
Help beside the question
Use: the evidence shows ___, but cannot yet show ___. Think trend, reference population and other evidence.
Answer guidance
A single point is a comparison with a reference group; health assessment needs a trend and other appropriate evidence.
Standard · 2 questions
1. Calculate
A length increases from 1.8 to 2.4 mm. Give the change with its unit.
Help beside the question
Subtract the first value from the second.
Answer guidance
0.6 mm.
2. Qualify
Why is one point on a growth chart not a diagnosis?
Help beside the question
Think trend, reference population and other evidence.
Answer guidance
A single point is a comparison with a reference group; health assessment needs a trend and other appropriate evidence.
Stretch · 2 questions
1. Calculate
A length increases from 1.8 to 2.4 mm. Give the change with its unit.
Help beside the question
Subtract the first value from the second.
Answer guidance
0.6 mm.
2. Extend the calculation
Calculate the percentage increase from 1.8 to 2.4 mm and state one limit.
Help beside the question
Change ÷ original × 100.
Answer guidance
0.6 ÷ 1.8 × 100 ≈ 33.3%; an increase in length does not reveal the contribution of division versus elongation.
Keep one useful science explanation. No additional participation record is required.