Parts of the Tree

A plant is usually considered a tree if it has one woody stem and branches. The woody stem is called a trunk. Tree trunks move water and nutrients or vitamins and minerals up and down the tree. The trunk is covered in a protective layer called bark, and each tree has roots. Roots are a big underground system of thin stems that anchor or hold the tree to the earth. Roots can reach deep down to find water and nutrients the tree needs to grow. Chlorophyll is what makes leaves green, and allows plants to gather energy from the sun. This process is called photosynthesis. Photosynthesis happens when green leaves use sunlight to turn water and carbon dioxide into sugars that the plant needs to grow. It is also how plants make oxygen.