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Science Launch G5 / Week 06 / Friday
5/6
Week 06 · Plants Build From Air and Water

Friday

Built from air
// Where a tree gets its wood
⏱ about 15 min

Friday: Built from air

Back at the oak tree, Rocket pats the bark like an old friend.

"So you are mostly air and water," he says to the tree. "That is amazing."

Raven laughs and writes in her notebook. "And sunlight energy to put it together," she adds.

Nova hovers in the dappled shade. "Every leaf above you is working right now," she says. "What do you notice?"

"It is sunny," Rocket says. "So the kitchens are open."

Putting it together

A plant takes in water through its roots and carbon dioxide through tiny holes.

Using sunlight, it makes sugar. It uses the sugar to build its body.

That is why a huge tree can grow from a tiny seed without using up the soil.

ClaimSupported by this week's evidence?
Plants get most of their material from air and water.?
Van Helmont's soil lost most of its weight.?
Leaves release water vapor.?
Plants release oxygen into the air.?
WHY THIS EXERCISEEach claim matches an experiment or a fact you checked this week.
EXPLAIN IT
  • Read the question.
  • Tap your answer.
A friend says, "Trees are made of dirt." What is the best reply?
A seed weighs almost nothing. It grows into a 100 pound tree. Did the soil lose 100 pounds? Type yes or no.
WHY THIS EXERCISEThe tree built itself mainly from air and water, so the soil barely changed.
Look around
Find the biggest tree near your home.
Imagine how much carbon dioxide it pulled from the air to grow.

Making the case

A strong scientific argument uses evidence.

The willow test shows the soil barely changed.

Photosynthesis explains where the material came from: air and water.

BUILD THE ARGUMENT
  • Read the question.
  • Tap your answer.
Which evidence shows soil is not the main source of a tree's material?
Which evidence shows water moves through plants?
A plant uses ____ to build its body.
A huge tree can grow without using up the ____.
FROM AIR TO WOOD
  • ?Carbon dioxide drifts in the air.
  • ?It enters a leaf.
  • ?Photosynthesis turns it into sugar.
  • ?The tree uses the sugar to build wood.
WHY THIS EXERCISEMuch of a tree's wood started as carbon dioxide in the air.
Try it
Find a leaf that has fallen to the ground.
Look at the bottom with a magnifier if you have one.
Carbon dioxide enters through tiny holes in leaves. Raven spotted some with her magnifier.
Make a poster that answers the question: Where does a tree's wood come from? Include the willow test.

You changed how you see every plant. Tomorrow is Launch Lab with your family.

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