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Science Launch G5 / Week 06 / Wednesday
3/6
Week 06 · Plants Build From Air and Water

Wednesday

Investigation: The leaf bag
// Where a tree gets its wood
⏱ about 15 min

Wednesday: Investigation: The leaf bag

Raven wraps a clear plastic bag around a leafy branch of the backyard bush. She ties it closed with a twist tie.

"We know roots take in water," she says. "But does water come out of the leaves too?"

Rocket checks the bag. "It is dry inside," he says. "Nothing yet."

Nova sets a timer for one hour. "Patience is a scientist's tool," she says. "Check the inside of the bag when the timer beeps."

Rocket sits down on the grass. "One hour," he says. "I can do one hour."

What you need

  • A clear plastic sandwich bag
  • A twist tie or a piece of string
  • A healthy leafy plant, indoors in a sunny spot or outdoors
  • A timer
Safety first
Plastic bags are only for the plant. Never put one near your face.
Ask a grown-up before choosing a plant, and do not pick or eat any part of it.
Wash your hands after touching plants and soil.

Steps

  1. Choose a leafy branch in a sunny spot.
  2. Gently slide the plastic bag over several leaves.
  3. Close the bag around the stem with the twist tie. Do not squeeze the stem tight.
  4. Make your prediction below.
  5. Wait one hour.
  6. Look closely at the inside of the bag.
  7. Remove the bag gently when you finish.
MAKE A PREDICTION
  • Read the question.
  • Tap your answer.
After one hour, what do you predict you will see inside the bag?
TimeWhat the inside of the bag looks like
Start
After 1 hour

Roots take in water from the soil. Water moves up through the plant.

Leaves release some of it as water vapor through tiny openings called stomata.

The bag traps the vapor, and it turns back into tiny drops. This is called transpiration.

What is it called when water leaves a plant's leaves as vapor? Type one word.
WHY THIS EXERCISEThe mist in the bag is evidence that water travels up the plant and out of its leaves.

Where the mist came from

The mist inside the bag came from the plant.

Water traveled up from the roots to the leaves.

The leaves released it as vapor, and the bag caught it.

LEAF BAG THINKING
  • Read the question.
  • Tap your answer.
What are the tiny openings in leaves called?
Why did we wait one hour?
Water leaving leaves as vapor is called ____.
The bag trapped the vapor, and it turned into tiny ____.

You watched a plant move water you could not see. Tomorrow we will learn how plants make food from air.

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