Which description is the best example of "genomic imprinting"?
A)A child inherits a trait that his paternal grandfather expressed but that his father did not express.
B)Boys can inherit only masculine traits from their fathers because women do not have a Y chromosome.
C)There is a qualitative difference in some gene alleles based on whether they are inherited from the mother or the father.
D)When the number of sex chromosomes is greater than normal, the resulting individual is most often infertile.

Question

Quizplus · Accepted Answer

Genomic imprinting is an epigenetic event in which a gene (or gene allele) is inactivated by means other than mutation, so the DNA sequence of the gene remains normal, but its expression is inhibited. It usually it occurs during gametogenesis, which can allow identification of whether the allele is maternally inherited or paternally inherited. The effect of an imprinted gene allele from one parent means that only the nonimprinted allele from the other parent is expressed. For the most part, when the nonimprinted gene allele is normal, its sole expression is not a problem. Problems arise with sole expression of mutated nonimprinted gene alleles. The most common example of genomic imprinting is that the same deletion of 15q can result in either Angelman syndrome or Prader-Willi syndrome, depending on which parent contributed the chromosomal deletion. This fact indicates that there is a qualitative difference in the alleles of 15q between men and women.

Which Description Is the Best Example of "Genomic Imprinting