Root Poster: Exterior and Interior Anatomy Directions: Using a piece of poster paper draw and label the parts of the exterior root. Once it is drawn and labeled identify the function of the labeled parts and color the different regions of the root. Parts to identify include primary root, secondary root, tertiary root, root hairs, region of maturation, region of elongation, and region of cell division. Then also draw, label, color and identify the interior of a root. Parts to identify include root cap, Apical meristem, epidermis, endodermis, pericycle, phloem and xylem.