a. The fully pigmented kernel is produced by the C gene (wild type).
b. One way of producing the unpigmented kernels is through the loss of the C gene by Ac-activated chromosome breakage at a Ds element. This results in the appearance of colorless or unpigmented phenotype, which is recessive trait.
Other way of producing the unpigmented kernels is insertion of Ds element into the C gene in the absence of an Ac element to mediate its excision. (The leaving element is said to excise from the chromosome).
Ac element is for the activator and Ds element is for dissociation. Ds prevent the expression of C. The inactivation of the C gene expresses the colorless parts of the kernel.