(a) If a devisee who is a descendant of the testator or a descendant of a testator's parent is deceased at the time the will is executed, fails to survive the testator, or is treated as if the devisee predeceased the testator by Chapter 121 or otherwise, the descendants of the devisee who survived the testator by 120 hours take the devised property in place of the devisee.
(b) Devised property to which Subsection (a) applies shall be divided into the number of shares equal to the total number of surviving descendants in the nearest degree of kinship to the devisee and deceased persons in the same degree of kinship to the devisee whose descendants survived the testator. Each surviving descendant in the nearest degree of kinship to the devisee receives one share, and the share of each deceased person in the same degree of kinship to the devisee whose descendants survived the testator is divided among the descendants by representation.