Tree increases in height and spread of branches each year by the addition of new growth at the living tip of the tree and at the ends of the branches.

Leaves or needles, where processes by which unavailable foods taken from the soil by the roots are changed so as to be usable by the tree. Leaves also serve as organs of breathing.

Inner bark, serves as transporting tissue for foods in solution.

Outer bark, protects the tree from injuries.

Heartwood, phisiologically dead, serves merely to strengthen and support the tree.

Sapwood serves as food transporting tissue between roots and other parts of tree.

Cambium layer, a living tissue by which the tree increases in diameter by cell division.

Very delicate root hairs take up water containing mineral elements from the soil. This is transported to the leaves and there changed so as to be usable tree food.