The B-I mutation in anthocyanin (red pigments) produces pigmented corn plants, whereas the B′ mutation in the same gene usually produces nearly unpigmented corn plants when homozygous (B´/B´). When homozygous B-I and B′ plants are intercrossed, the F1 plants are essentially unpigmented, like the B′ homozygotes. If this outcome were due simply to the dominance of B′ to B-I, then a self-cross of the F1 plants (B´/B-I) should generate B-I-colored homozygotes as approximately 1/4 (B-I/B-I) of the F2 progeny. Instead, no F2 are pigmented. Intercrosses of the F2 and of further generations do not restore the pigmented phenotype. What is the term for this type of inheritance?
A) Mendelian inheritance
B) organelle genome inheritance
C) allelic inheritance
D) epigenetic inheritance

Question

Quizplus · Accepted Answer

This type of inheritance is known as epigenetic inheritance because the phenotype is not solely determined by the genotype but also influenced by other factors such as gene expression regulation and chromatin modifications. In this case, it appears that there is a heritable epigenetic modification that prevents the pigmented phenotype from being expressed despite the presence of the B-I allele. This type of inheritance is non-Mendelian and not related to inheritance of organelle genomes.

The B-I Mutation in Anthocyanin (Red Pigments) Produces Pigmented Corn