How did a tree travel halfway around the world?

How did a tree travel halfway around the world?

Lesson narration:
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Discuss:
How could the same kind of tree grow in only two places, thousands of
miles apart?
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Discuss:
How could a koa seed travel all the way from Hawaii to Réunion?
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Discuss:
How will the structure around these seeds change how they travel
through the air?
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Step
01/18
You’ll work with a partner.
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Step
02/18
Get your supplies.
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Step
03/18
Write your name on the back of your maple model. Then fold dot A to
dot B. When you’re done, the gray triangle should be covered.
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Step
04/18
Fold the triangle up so that it covers the picture of a seed.
Slide your paper clip on the bottom of your seed.
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05/18
Cut along the dotted line. Stop at the stop sign. When you’re done,
this part of your maple model should have two flaps.
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06/18
Fold flap 1 on the line toward you. Fold flap 2 on the line away from
you. Push your folded flaps up with your fingers so they stick out
sideways.
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07/18
When your teacher tells you, stand up next to your desk. Pretend to
be a tree. Root your feet to the ground, stand up tall, and stretch
your arms up.
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Step
08/18
Hold your maple model from the side with two fingers. Hold it high
above your head. Drop your model and observe how it falls. Repeat.
You have 3 minutes to test.
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09/18
Discuss:
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Step
10/18
Write your name on the back of your rain tree model. Cut along the 2
dotted black lines. Stop at the stop sign. When you’re done, you’ll
have two slits.
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Step
11/18
Hold the two ends of your printout and make a “U.”
Slide the slit at one end into the slit at the other.
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Step
12/18
Pretend to be a tree! Hold your rain tree model in the middle with the
ends pointing sideways. Hold it above your head, drop it, and observe
how it falls.
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Step
13/18
Work with your partner to explore how both of your models fall.
Compare what is the same and what is different.
You have 3 minutes to test.
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Step
14/18
Discuss:
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Step
15/18
Write your name on the back of your koa model.
Fold it in half along the black line.
Run your fingernail along the fold to crease it.
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Step
16/18
Hold your koa model with two fingers at one end. Hold your model
above your head, drop it, and observe how it falls. Repeat.
You have 3 minutes to test.
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Step
17/18
Discuss:
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Step
18/18
Discuss:
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Do you think the wind could carry a koa seed halfway across the world?
Why or why not?
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Discuss:
What could help a cherry seed move from one place to another?
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Discuss:
What kind of animal could carry a koa seed across the ocean to the other
side of the world?
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seed


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a part of a plant that can grow into a baby plant
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seedling


2 of 10

a young plant that grows from a seed
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structure


3 of 10

the specific form and shape of something
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disperse


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to move and spread out
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wind dispersal


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when the wind moves a seed from one place to another
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water dispersal


6 of 10

when water moves a seed from one place to another
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animal dispersal


7 of 10

when an animal moves a seed from one place to another
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observe


8 of 10

to pay close attention to something
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compare


9 of 10

to notice what is similar and what is different between things
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model


10 of 10

a pretend version of something that scientists use when the real thing is too big, small, or complicated to work with
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Lesson narration:

Activity Prep

Print Prep

THIS LESSON WAS REVISED ON FEB 1, 2023. Here is a link to the previous version.
In this lesson, students investigate the mystery of the koa tree, a type of tree that grows in only two places—islands halfway across the world from one another. In the activity, students develop three different physical models of seed structures. They observe how structure affects the seed’s function in dispersing away from the tree. Then, they use these observations to evaluate whether koa seeds are likely dispersed by wind, water, or animals.

Preview activity

Exploration

10 mins

Wrap-Up

15 mins

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