Which genetic principle explains why traits can skip generations?

The concept that traits can skip generations is best explained by the principle of recessiveness. A recessive trait is one that is expressed in the phenotype only when an individual has two copies of the recessive allele (homozygous). If an individual possesses just one copy of a recessive allele (heterozygous), that individual will exhibit the dominant trait instead.

This means that if two parents carry one copy of a recessive allele, the recessive trait may not be visible in their phenotype. However, each child of these parents has a chance of inheriting two copies of the recessive allele, one from each parent, allowing the trait to be expressed even if it was not visible in the parents. Thus, the trait can appear in the offspring even if it seems to have "skipped" the parents' generation, as the dominant trait is expressed in them while the recessive trait remains hidden.

In contrast, independent assortment relates to the distribution of different genes independently of one another, segregation pertains to how allele pairs separate during gamete formation, and dominance explains the relationship between dominant and recessive alleles but does not directly address the skipping of generations.