Which of the following is a characteristic of non-additive genetic effects?

Non-additive genetic effects encompass both dominance and epistatic interactions, which are key factors that impact how traits are expressed. Dominance refers to a scenario where the effect of one allele masks the effect of another allele at the same locus, while epistasis involves the interaction between alleles at different loci, where the presence of one allele can affect the expression of another allele. Together, these interactions create a more complex inheritance pattern that cannot be accurately predicted by simply adding the effects of individual alleles, which would be the case in purely additive genetic effects.

Understanding non-additive effects is crucial because they contribute significantly to the phenotypic variation observed in populations. This complexity can influence selection processes, breeding outcomes, and the overall understanding of genetic architecture in evolutionary biology.

The other options, while related to genetic concepts, do not fully capture the essence of non-additive effects in the same way. Interference between different loci is too broad to summarize the specific interactions indicated in option D, and the combined action of all genes leans more towards additive effects, which do not consider the complexities of dominance and epistasis. Masking of allele expression at the same locus pertains mainly to the phenomenon of dominance, but it alone does not encompass the wider