Mendel’s analysis of dihybrid crosses revealed that the segregation of allele pairs for diff erent traits is independent; this fi nding is known as Mendel’s Principle of Independent Assortment. When...

Mendel’s analysis of dihybrid crosses revealed that the segregation of allele pairs for diff erent traits is independent; this fi nding is known as Mendel’s Principle of Independent Assortment. When individuals that diff er in two traits are crossed, and their progeny are intercrossed, the result is four diff erent types that occur in a ratio of 9:3:3:1, Mendel’s dihybrid ratio. This occurs because of the independent behavior of diff erent homologous pairs of chromosomes during meiosis I.

■ Which is more important in terms of explaining Mendel’s laws, meiosis I or meiosis II?