In the transverse section of roots either it may be monocot root or dicot root, the outermost layer is called as epiblema(epidermis with unicellular root hair). Followed by epiblema is present cortex which is several layered parenchymatous cells with intercellular spaces.
The innermost layer of cortex is endodermis which is made of compactly arranged barrel-shaped cells. All tissue in the inner side of endodermis is together called as stele. Stele is comprised of pericycle, vascular bundles and pith.
Dicot root shows the secondary growth while the monocot root does not undergo any secondary growth. But the arrangement of vascular bundles in both monocot and dicot roots are similar. That is exarch type. In exarch type of arrangement the metaxylem are present towards the pith and the protoxylem are present towards the periphery. So according to the question only roots have such arrangements.
