Answer
The spontaneous activation of the Ade2 gene leads to the white sectors. This active gene can be propagated to the daughter cell from the mother cell.
Work Step by Step
The Ade2 gene is inactivated when placed near telomeres and this leads to the red color of the colony. But sometimes there is spontaneous activation of the genes (resulted from spontaneous de-condensation of the gene) that leads to the formation of the white sectors in the red colony. Once the gene is activated it is passes on to the next generations
