Which Mendelian law states that genes for different traits are inherited independently?

The Mendelian law stating that genes for different traits are inherited independently is the law of independent assortment. It describes how allele pairs for separate traits can be distributed into gametes independently during meiosis.

Mendel developed this principle from dihybrid crosses involving two traits at once, such as pea-seed color and seed shape. If the genes assort independently, inheriting an allele affecting one trait does not determine which allele is inherited for the other trait. This creates combinations that were not necessarily present together in the original parents.

The physical basis of independent assortment is the random orientation of homologous chromosome pairs during metaphase I of meiosis. Because each pair aligns independently of other pairs, gametes can receive different combinations of maternal and paternal chromosomes.

The law is an idealized rule rather than a universal description of every inheritance pattern. Genes located close together on the same chromosome may be genetically linked and therefore inherited together more often than expected. This law is also distinct from the law of segregation, which concerns the separation of the two alleles of a single gene pair.