When performing genetics studies like the fruit fly cross, the expected phenotypic ratios may not be the same as the actual ratios observed. Name one reason for this difference?

Answer 1

One reason for the difference between expected phenotypic ratios and actual observed ratios in genetics studies, such as those involving fruit fly crosses, is incomplete dominance or co-dominance. In such cases, the phenotypes of heterozygous individuals do not blend in the expected Mendelian ratios but rather exhibit characteristics that differ from either homozygous phenotype. This can lead to outcomes that deviate from the expected 3:1 or 9:3:3:1 ratios seen in classical Mendelian inheritance.

Other factors that could contribute to the difference include environmental influences, epistasis (gene interactions), genetic linkage, and sample size variability.