Which of the Following is True Regarding Genomic Imprinting

Question

Which of the following is true regarding genomic imprinting?
A) It is an epigenetic phenomenon.
B) It occurs in most animals.
C) It always involves inactivation of genes through direct DNA methylation.
D) It can "unmask" recessive alleles but cannot "mask" dominant ones.
E) All of the above.

Accepted Answer

Genomic imprinting, observed in placental mammals and some flowering plants, is an epigenetic form of inheritance. It is mediated through DNA methylation in mammals, but it does not always involve gene inactivation by direct methylation. It can unmask recessive alleles or mask dominant alleles.