Opening

GROW · SCIENCE · Lesson 3 of 6

A seed has no engine

Learning intention

Explain how seed or fruit structures can aid dispersal and evaluate a controlled paper model.

How could a seed travel away from its parent?

Look for a structure and a force or carrier.

Success looks like

Link a structure to a dispersal mechanism.
Identify what changes and what stays the same in a model test.
Use repeat data without claiming measured outdoor dispersal distance.

Retrieval

GROW · SCIENCE · Lesson 3 of 6

Seed, fruit and a fair comparison

R1. What can a seed develop into?

R2. Where are seeds found in a flowering plant’s fruit?

R3. Why repeat a measurement?

I do

GROW · SCIENCE · Lesson 3 of 6

I connect structure to a journey

A sycamore wing interacts with air.

A burdock hook can attach to fur.

The transported object can include fruit around a seed.

Different structures, different dispersal routes

Diagram description

Two schematic botanical structures are compared without a connecting arrow: sycamore winged fruit with seed-bearing region, and burdock hooked burr enclosing fruits. Structures are simplified and not to scale.

I do

GROW · SCIENCE · Lesson 3 of 6

I design a fair paper comparison

Change the paper shape.

Keep mass, release height and method the same.

Measure fall time, not imagined travel distance.

Fair paper-model drop comparison

Diagram description

Two paper shapes are released from the same marked height into a clear floor area. The measured quantity is fall time. The models have equal original paper dimensions and retained mass, with shape as the changed feature.

Continue within this stage’s shared time.

I do

GROW · SCIENCE · Lesson 3 of 6

I keep the claim within the measurement

A longer descent gives air more time to act.

We measured seconds to the floor.

We did not measure real seeds outdoors.

What the paper model can tell us

Diagram description

A simplified scientific sequence: Observed:
longer fall time; Possible effect:
more time in air; Not measured:
outdoor distance. Paper models test one feature. Real seed journeys
also depend on wind, release height and surroundings.

Continue within this stage’s shared time.

We do

GROW · SCIENCE · Lesson 3 of 6

Model design jury

Go to interactive investigation

W1. Match A–C to wind or animal dispersal.

W2. Compare the repeated fall times.

Which shape stayed in the air longer here?

Constructed sample data only; no outdoor distance was measured.
Constructed model	Trial 1 / s	Trial 2 / s	Trial 3 / s
Compact paper	0.8	0.9	0.7
Rotor paper	1.4	1.5	1.3

My response — say it, sketch on paper or type

Dispersal jury: structure, method and claim

Predict first, test the model, then explain using the evidence. Move at your own pace; paper W1–W3 tasks assess the same reasoning.

Decision 1 of 3

Which structure can attach to animal fur?

Choose, test, then explain together. Evidence diagrams appear only after your test. Diagram transitions explain the model; they do not represent real elapsed time. Use Pause model to stop transitions and model controls, or your device’s reduced-motion setting. The printed We do activity provides the paper route.

We do

GROW · SCIENCE · Lesson 3 of 6

Detect a broken comparison

A team changes shape and adds a heavy clip.

Can it attribute the difference only to shape?

Name the repair.

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

We do

GROW · SCIENCE · Lesson 3 of 6

Choose the honest caption

W3. Repair “The rotor proves sycamore seeds always travel farther”.

State the measured result and one limit.

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

Hinge

GROW · SCIENCE · Lesson 3 of 6

Which quantity was measured?

Choose the conclusion that fits the test.

You do

GROW · SCIENCE · Lesson 3 of 6

Your independent investigation

Choose one response route.

Explain a structure and evaluate the model evidence.

Use numerical values and a clear limitation.

My response — say it, sketch on paper or type

You do

GROW · SCIENCE · Lesson 3 of 6

Use the evidence

Name what changed and what stayed the same.

Keep seconds attached to fall-time values.

Do not claim a measured distance.

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

You do

GROW · SCIENCE · Lesson 3 of 6

Check before sharing

Does my explanation answer the question?

Have I named the evidence or process?

Have I kept the conclusion within its limits?

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

Review

GROW · SCIENCE · Lesson 3 of 6

Compare and improve

Show one structure–mechanism link.

Check a numerical comparison.

Improve one claim about real seed journeys.

My response — say it, sketch on paper or type

Review

GROW · SCIENCE · Lesson 3 of 6

A question worth investigating

Suggest one next question about this lesson’s evidence.

Choose a question whose answer would improve our model.

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

Exit

GROW · SCIENCE · Lesson 3 of 6

Show the science you can explain

E1. Explain how a wing can aid dispersal.

E2. Give evidence from the paper model.

E3. Give one limit of this model.

My response — say it, sketch on paper or type

My science task sheets

Choose one route with your teacher. Shared evidence and the exit sheet appear in every route. Your work stays here while the page is open; save it before closing.

1 • Shared evidence: dispersal jury

All fall times below are constructed sample data, not class observations.

A • Sycamore

A seed is enclosed in the base of a winged fruit. The wing can slow descent and help wind carry it.

B • Burdock

Hooked burrs can attach to animal fur and be carried away before falling off.

C • Fleshy fruit

Some animals eat fruit, digest the flesh and later pass surviving seeds elsewhere. Survival is not guaranteed.

D • Test method

Constructed test: same paper stock and original 4 × 16 cm size, all paper retained; same 1.5 m release height and rule, still indoor air. Shape changes. Fall time is measured.

Model	Trial 1 / s	Trial 2 / s	Trial 3 / s
Compact paper	0.8	0.9	0.7
Rotor paper	1.4	1.5	1.3

W1. Match A–C to a dispersal mechanism. W2. Compare one pair of times.W3. Improve the “always travels farther” claim and name a limit.

2 • Supported route: structure and evidence

Use page 1. Point, circle or explain with a short sentence.

S1. A sycamore wing mainly helps interaction with … Air An animal’s digestive system

S2. Burdock hooks can help attachment to … Animal fur A pollen tube

S3. Complete: In trial 1, rotor paper took ____ s and compact paper took ____ s. The ____ stayed in the air longer.S4. Name one condition kept the same in the paper test.S5. Does this prove real outdoor travel distance? Explain.

3 • Standard route: design jury report

Use the shared evidence and state exactly what was measured.

N1. Explain a wing, hook and fleshy-fruit dispersal route.N2. Compare the two models using two pairs of times and units.N3. Name the changed variable, two controls and the measured quantity.N4. Explain why adding a clip to one model weakens a shape-only comparison.N5. Give a bounded conclusion and one model limitation.

4 • Stretch route: design a stronger test

Do not confuse fall time with distance.

T1. Calculate the mean fall time for each paper shape and compare them. Show working.T2. Explain why the model supports a possible role for a wing but cannot prove every real seed travels farther.T3. Design a later model test of horizontal distance using controlled airflow. Name the change, two controls, repeated measurement and units.T4. Evaluate “plants grew hooks because they wanted animals to carry them”. Write a scientific replacement without intention.

5 • Exit and reflection

Use evidence and an honest limit.

E1. Explain one structure–dispersal link.E2. Compare two fall times from page 1 using units.E3. What does the paper model not establish?E4. Name a control and explain its purpose.Reflection. What should the next model measure?