The paternal and maternal chromosomes of the bivalent pairs can face either pole. This causes genetic variation.
The Principle of Independent Assortment describes how different genes independently separate from one another when reproductive cells develop.
During meiosis, the pairs of homologous chromosome are divided in half to form haploid cells, and this separation, or assortment, of homologous chromosomes is random.
This means that all of the maternal chromosomes will not be separated into one cell, while the all paternal chromosomes are separated into another.
Instead, after meiosis occurs, each haploid cell contains a mixture of genes from the organism’s mother and father.
Taken from here.
If we have a pair of allele(one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome.)
AaBb on chromosome then during meiosis all these alleles will separate independently from one another only single allele will be transferred to one gamete. this is further understand by this image