How does the law of segregation explain the formation of gametes?

The law of segregation, formulated by the botanist Gregor Mendel, explains that genes are transferred as distinct units from one generation to the next.1

During the formation of gametes (sex cells), the two alleles of a gene pair—which reside on paired chromosomes—separate from one another. As a result of this segregation, each gamete receives only one allele from the original pair.12

In modern biological terms, this process occurs during meiosis, where homologous chromosomes separate and move into different cells. Because the alleles segregate into different gametes, an organism produces equal numbers of gametes carrying each form of the gene. This ensures that when gametes from two parents unite at random, the resulting offspring reflect the proportions dictated by these genetic combinations.312