What is gene combination value?

What is gene combination value?

• A. Dominance and epistasis effects
• B. Additive effects only
• C. Environmental influences
• D. Phenotypic value of animals

Answer: (A)

Gene combination value represents the non-additive part of the genetic contribution to a trait. It captures how alleles interact within and between loci to produce effects that aren’t simply the sum of individual allele effects. This includes dominance at a single locus (how the heterozygote’s phenotype differs from the homozygotes) and epistasis between loci (how the effect of one gene depends on alleles at another gene). In contrast, additive effects are the straightforward, heritable portion that sums across loci and is reliably transmitted from parents to offspring, forming the breeding value breeders typically select for. Environmental influences also affect the phenotype but are separate from gene combination value. So the best answer is the part that involves dominance and epistasis.

Gene combination value represents the non-additive part of the genetic contribution to a trait. It captures how alleles interact within and between loci to produce effects that aren’t simply the sum of individual allele effects. This includes dominance at a single locus (how the heterozygote’s phenotype differs from the homozygotes) and epistasis between loci (how the effect of one gene depends on alleles at another gene). In contrast, additive effects are the straightforward, heritable portion that sums across loci and is reliably transmitted from parents to offspring, forming the breeding value breeders typically select for. Environmental influences also affect the phenotype but are separate from gene combination value. So the best answer is the part that involves dominance and epistasis.