By counting the number of tree rings in a tree's trunk, you can tell how old the tree was. A trophic level is a level of the grazing food chain . They are also called equatorial rainforests. The trunk of a tree is the stem that supports the crown. A tuber is a modified root that stores nutrients.
Potatoes are tubers.
There are many different types of tumbleweed - they live in the prairie and plains of the United States. Tussock grass grows in clumps and has fine hair-like leaves. In summer it produces fine green to yellow inflourences. A type species is the species of an organism from which a new genus is named. For example, Tyrannosaurus rex is the type species for the genus Tyrannosaurus.