Exploring the Parts of a Tree

Study Notes

A tree has three main parts: the crown, trunk, and roots.
The crown includes leaves and branches that work like a food factory, collecting sunlight and carbon dioxide to produce food for the tree.
The crown also provides oxygen and protects the ground from heavy rain and hot sun.

The trunk holds up the crown, protects the inner parts, and transports essential materials to different parts of the tree.
The trunk has five layers:
- Bark: the hard, outer layer that protects the trunk from bad weather and animals.
- Phloem: a sugar pipeline that carries sugary food to the leaves.
- Cambium: the growth center that makes new cells for the trunk and branches to grow thicker.
- Xylem: a pipeline that carries water and nutrients from the roots to the crown.
- Heartwood: the center of the trunk, made up of old xylem cells that provide support and strength.

When a tree's trunk is cut, its different layers look like rings, with the heartwood at the center.
Scientists can use tree rings to determine the age of a tree.

Leaves are the site for photosynthesis, the process of using sunlight, carbon dioxide, and water to create sugar.
The vascular tissue responsible for sugar distribution to the leaves is called phloem.
The dark, non-living part of the tree located at its center is called heartwood.
The bark is the protective layer of the tree, found outside the cambium.
The xylem transports water and nutrients from the roots to the aerial parts of the tree.