During fertilisation, 1 gamete from each parent combines to form a zygote. Because of recombination and independent assortment in meiosis, each gamete contains a different set of DNA. This produces a unique combination of genes in the resulting zygote.
The process that produces gametes is called meiosis. During meiosis, homologous chromosomes (1 from each parent) pair along their lengths. ... At each chiasma, the chromosomes break and rejoin, trading some of their genes. This recombination results in genetic variation.
