LAUNCH · Edexcel GCSE Biology 1BI0 Foundation · Paper 1 · Topic 1 · Week 4
| Key word | What it means |
|---|---|
| diffusion | The net movement of particles from a higher to a lower concentration. |
| concentration gradient | The difference in concentration between two areas. |
| net movement | The overall movement, once movement in both directions is counted. |
| passive | Requiring no energy from the cell. |
| surface area | The total area available for particles to cross. |
Session plan: 40-minute session: Arrival 3; overview 1; I Do 1 4; We Do 1 4; I Do 2 3; We Do 2 4; independent work 15; feedback and next step 3; exit 3. Title orientation is untimed. The optional two-minute evidence check sits inside independent time. Keep extra practice available; use the core question, a contrasting example and a recheck before extending.
Name: ____________________ Tier ringed by adult: ◆ Supported ▲ Standard ★ Stretch Date:
I can explain diffusion and the factors that affect its rate.
Complete from the word bank: diffusion is the net movement of particles from ____ to ____ concentration.
Write a definition of diffusion using the words 'net movement'.
Write a definition of diffusion and name one factor that speeds it up.
Oxygen into the blood at the alveoli → ______________________________
Carbon dioxide out of a cell → ______________________________
A smell spreading across a room → ______________________________
Glucose pumped into a root hair against the gradient → ______________________________
Water across a partially permeable membrane → ______________________________
Net movement down a gradient, no energy used → ______________________________
Oxygen diffuses from the alveolus into the blood because there is a higher concentration of oxygen in the alveolus than in the blood. The alveolus wall is one cell thick, so the diffusion distance is short and the rate is high.
You apply it, out loud as you write: 'Oxygen diffuses from the alveolus into the blood because oxygen concentration is higher in the alveolus. The wall is one cell thick, so the diffusion distance is short, which increases the rate.' Direction, reason, adaptation.
diffusion, concentration gradient, net movement, passive, surface area
You apply it, out loud as you write: 'Oxygen diffuses from the alveolus into the blood because oxygen concentration is higher in the alveolus. The wall is one cell thick, so the diffusion distance is short, which increases the rate.' Direction, reason, adaptation.
diffusion, concentration gradient, net movement, passive, surface area
You apply it, out loud as you write: 'Oxygen diffuses from the alveolus into the blood because oxygen concentration is higher in the alveolus. The wall is one cell thick, so the diffusion distance is short, which increases the rate.' Direction, reason, adaptation.
diffusion, concentration gradient, net movement, passive, surface area
Task: Label the alveolus diagram and complete three gap-fill definition sentences from the word bank.
Task: Label and annotate the alveolus diagram, then answer three application questions on rate factors.
Task: Annotate the diagram, answer the application questions, and explain why a person with damaged alveoli has reduced gas exchange, referring to surface area and distance.
Name two factors that increase the rate of diffusion.
Pearson Edexcel GCSE (9–1) Biology 1BI0 (Foundation, grades 1–5); GCSE Combined Science 1SC0 F where appropriate; AQA UAS science units
Records what was observed, and at which level of independence.
| Pupil | ____________________ |
| Lesson | Discover: Diffusion — LAUNCH Science · Week 4 |
| Date | ____________________ |
Observed in this lesson
☐ Defined diffusion using 'net movement' and 'concentration gradient'.
☐ Named three factors affecting rate.
☐ Applied diffusion to gas exchange in the alveoli.
Assessor comment
Ring the tier the pupil actually worked at
| ◆ Supported | ▲ Standard | ★ Stretch |
Assessor name ______________ Role ____________ Signature ______________ Date ________
Space: Lung and breathing content can land close to home. You can work from the diagram and skip the discussion.
Voice: If a definition on the board does not make sense, say so — precision is the whole point today.
Audience: Your annotated diagram goes into the Topic 1 folder for the W7 review.
Influence: The class picks the real-world example we use for the exam-style practice at W7.
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:
Keep with your portfolio.
| Pupil name: | Date: |
| WWW (What Went Well): | |
| EBI (Even Better If): | |
| Level worked at: Supported / Standard / Stretch | Evidence filed: Yes / Not yet |
| Pupil response — my next step: | |