The law of independent assortment explains how different genes independently separate from one another when reproductive cells develop. This means that the alleles for different traits are passed independently of one another from parents to offspring.
For example, consider a plant that has two traits: flower color (which can be either red or white) and plant height (which can be either tall or short). According to the law of independent assortment, the allele a plant inherits for flower color does not affect the allele it inherits for plant height. This means that the inheritance of one trait does not influence the inheritance of another, leading to a variety of combinations in the offspring.
This principle can be observed in dihybrid crosses, where two traits are analyzed simultaneously. If we cross two plants that are heterozygous for both traits (e.g., RrTt), the offspring will display four possible phenotypes in a 9:3:3:1 ratio. This ratio is the result of the independent segregation of each trait’s alleles during gamete formation, illustrating the law of independent assortment at work.