Explain the process of secondary growth in roots.

(N/A) $\rightarrow$ In the dicot root,the vascular cambium is completely secondary in origin. It originates from the tissue located just below the phloem bundles,a portion of pericycle tissue,above the protoxylem,forming a complete and continuous wavy ring,which later becomes circular.
$\rightarrow$ Further events are similar to those already described above for a dicotyledon stem. The cambial ring becomes active and begins to cut off new cells,both towards the inner and outer sides. The cells cut off towards the center mature into secondary xylem,and the cells cut off towards the periphery mature into secondary phloem. The cambium is generally more active on the inner side than on the outer side. As a result,the amount of secondary xylem produced is more than secondary phloem and soon forms a compact mass.