66. Differential expression of the genetic material depending on its parentage of inheritance is
known as:
A. Penetrance,
B. Expressivity,
C. Epistasis

D. Genomic imprinting

Introduction:

Genetic inheritance and expression can be quite complex, often depending on various factors. One concept that explains the differential expression of genetic material based on the parentage of inheritance is essential in understanding how traits are passed down from one generation to the next. This phenomenon is associated with genetic imprinting and can lead to different expressions depending on whether a gene is inherited from the mother or the father.

Key Genetic Terms:

Before diving into the main topic, let’s briefly review the three genetic terms that may be associated with the concept:

• Penetrance: This refers to the proportion of individuals with a particular genotype who exhibit the associated phenotype. In other words, it measures the likelihood that a gene will express itself when inherited.

• Expressivity: This refers to the degree or intensity with which a particular genotype is expressed in the phenotype. Even if a gene is present, it may show varying degrees of expression across individuals.

• Epistasis: This term refers to the interaction between different genes, where one gene can mask or modify the expression of another gene. It doesn’t necessarily relate directly to parentage but is important in understanding how multiple genes influence traits.

Differential Expression Based on Parentage:

The specific phenomenon of interest here is known as genetic imprinting, where genes are expressed differently depending on whether they are inherited from the mother or the father. This form of inheritance, also called parent-of-origin effects, is an example of differential gene expression based on the source of the gene.

The Correct Answer:

The correct answer is not Penetrance, Expressivity, or Epistasis in this case, as none of these directly describe the parentage-based expression. Instead, this phenomenon is referred to as genetic imprinting or parent-of-origin inheritance, where expression can vary based on whether a gene is inherited from the maternal or paternal side.

However, to address the options provided:

• A. Penetrance: This term does not describe parentage-dependent expression but rather the likelihood of expressing a gene if it’s inherited.

• B. Expressivity: While expressivity deals with the degree of expression, it doesn’t specifically account for whether a gene is expressed differently based on its inheritance from the mother or father.

• C. Epistasis: This refers to gene interaction, not parentage-specific expression.

Conclusion:

In summary, the correct concept describing the differential expression of genetic material based on its inheritance from either the mother or the father is genetic imprinting. While terms like penetrance and expressivity describe the likelihood and intensity of gene expression, they don’t directly address this parent-specific phenomenon.