A heavy rain soaked the yard last night. This morning, Raven finds the old oak still standing tall and dry inside.
Rocket kneels by its trunk. "Its roots go everywhere," he says, tracing bumps in the dirt. "Why so many?"
"What do you notice about the leaves way up high?" Raven asks.
Nova flies up to a branch, then down to the roots. "Would you like a hint?" she asks. "Water starts down here. The leaves need it up there."
Roots hold a plant in the ground. Tiny root hairs take up water and minerals from the soil.
A tree trunk is a big stem. Stems support the plant and carry water up to the leaves.
Leaves use sunlight to make food for the plant. This is called photosynthesis. Leaves also release oxygen.
Bark covers the trunk and branches. It protects the tree from disease, fire and injury.
The saguaro cactus lives in the desert. Its shallow roots spread wide to catch water from even light rain.
Its pleats stretch like an accordion when it soaks up rain. They shrink as it uses the stored water.
Its spines protect it from animals, give shade and help stop water loss in dry winds.
A tree is a team of structures.
Roots grab water. The trunk lifts it. Leaves use it with sunlight to make food.
Bark wraps around the outside like armor.
Each part does a different job.
| Statement | True or false? |
|---|---|
| A tree trunk is a big stem. | ? |
| Root hairs take up water and minerals. | ? |
| Saguaro pleats shrink when it soaks up rain. | ? |
| Saguaro spines can give shade. | ? |
You traced water through a tree! Tomorrow you watch water climb a stem with your own eyes.