Which term describes the phenomenon where one gene can mask the expression of another gene?

Which term describes the phenomenon where one gene can mask the expression of another gene?

• A. Multigenic inheritance
• B. Dominance
• C. Epistasis
• D. Modifier gene interaction

Answer: (C)

The phenomenon described in the question refers to epistasis, which occurs when the expression of one gene is affected or completely masked by one or more other genes. In this interaction, the gene that is masking another can influence the phenotype, demonstrating how multiple genes can interact in complex ways to determine a trait. For example, if we consider two genes that govern coat color in mice, one gene could determine the pigment color while another gene might dictate whether the pigment is expressed at all. Even if the pigment gene is fully functional, if the second gene prevents its expression, the animal will exhibit a phenotype that reflects the upper gene's influence instead. Understanding epistasis is crucial in genetics because it reveals that phenotypic outcomes often arise from more than simple dominance relationships between alleles at a single locus. Instead, they can be the result of intricate genetic interactions, enriching the field of genetics beyond the classical Mendelian framework.

The phenomenon described in the question refers to epistasis, which occurs when the expression of one gene is affected or completely masked by one or more other genes. In this interaction, the gene that is masking another can influence the phenotype, demonstrating how multiple genes can interact in complex ways to determine a trait.

For example, if we consider two genes that govern coat color in mice, one gene could determine the pigment color while another gene might dictate whether the pigment is expressed at all. Even if the pigment gene is fully functional, if the second gene prevents its expression, the animal will exhibit a phenotype that reflects the upper gene's influence instead.

Understanding epistasis is crucial in genetics because it reveals that phenotypic outcomes often arise from more than simple dominance relationships between alleles at a single locus. Instead, they can be the result of intricate genetic interactions, enriching the field of genetics beyond the classical Mendelian framework.