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Grow It 3-5 / Week 04 / Grow It Day
6/6
Week 04 · Roots, Stems and Water

Grow It Day

Grow It Day: Catch the Water
// How water travels up a plant
⏱ about 15 min

Grow It Day: Catch the Water

Rocket holds up a clear plastic bag. "Today we catch invisible water!" he says.

Raven looks at the leafy branch. "What do you notice now? The leaves look dry."

Nova floats near the branch. "Water vapor is hard to see," she says. "What might happen if it gets trapped?"

The family gets ready to find out.

  1. Roots take in water and minerals. They also anchor and support the plant.
  2. Root hairs give roots a huge surface for taking in water.
  3. Xylem tubes carry water up. Phloem tubes carry food around.
  4. Water vapor leaves through stomata. This is called transpiration.
  5. Heat and wind make plants lose water faster.
◇ THE BAG TEST
Pick a leafy houseplant or a low tree branch in the sun.
Make sure the leaves are dry before you start.
A grown-up slips a clear plastic bag over a few leaves.
The grown-up closes the bag gently around the stem with a twist tie.
Wait two to three hours.
Look at the inside of the bag. What do you see?
The grown-up takes the bag off, so the plant can breathe freely.
Safety first
A grown-up puts the bag on and takes it off.
Plastic bags are never for heads or faces.
Do not touch or pick unknown wild plants. Use a plant you know.
Never eat any leaf, berry or flower. Wash your hands after.
For a grown-up
Tie the bag loosely so the stem is not squeezed.
Ask: where did the drops come from? Water vapor from the leaves turned back into liquid.
TimeWhat I see inside the bag
Start
After 1 hour
After 2 to 3 hours
WHAT HAPPENED?
  • Read the question.
  • Tap your answer.
Tiny drops show up inside the bag. Where did that water come from?
What is the name for this water leaving the leaves?
Would you get more drops on a hot day or a cold day?

Fantastic water catchers! Next week we find out how leaves use light to make food.

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