The law of segregation states that the parental genes must separate randomly and equally into gametes during meiosis so there is an equal chance of the offspring inheriting either allele. No allele is favored or has an advantage over another.

Chromosome segregation is the process in eukaryotes by which two sister chromatids formed as a consequence of DNA replication, or paired homologous chromosomes, separate from each other and migrate to opposite poles of the nucleus. This segregation process occurs during both mitosis and meiosis. Chromosome segregation also occurs in prokaryotes ...

The physical basis of Mendel’s law of segregation is the first division of meiosis in which the homologous chromosomes with their different versions of each gene are segregated into daughter nuclei. The behavior of homologous chromosomes during meiosis can account for the segregation of the alleles at each genetic locus to different gametes.

How does independent assortment of chromosomes operate during meiosis? In Meiosis I members of homologous pairs separate during anaphase. The separation of each pair is random with respect to all the other pairs. For each pair there is a maternal and a paternal chromosome which came from the mother and father respectively.