Which of the following could be a result of selective breeding in organisms with interacting genes?

• A. Production of only homozygous individuals for all genes
• B. Complete elimination of genetic variation in the population
• C. Increased frequency of desirable traits due to selection for specific gene combinations
• D. Random assortment of alleles without any change in trait frequency

Answer: (C)

Verified step by step guidance

1. Understand the concept of selective breeding: it involves choosing parents with specific desirable traits to produce offspring with those traits, thereby influencing gene frequencies in the population.
2. Recognize that interacting genes (epistasis) means the effect of one gene depends on the presence of one or more 'modifier genes', so selecting for specific gene combinations can enhance certain traits.
3. Evaluate each option by considering the genetic consequences of selective breeding: for example, producing only homozygous individuals for all genes is unlikely because multiple genes and alleles segregate independently.
4. Consider that complete elimination of genetic variation is improbable because mutations and recombination continually introduce variation, and selective breeding usually reduces but does not eliminate variation.
5. Conclude that selective breeding can increase the frequency of desirable traits by selecting specific gene combinations, which aligns with the concept of increasing favorable allele combinations through non-random mating.