Great Migration: Life for Migrants in the City. By the end of 1919, some 1 million blacks had left the South, usually traveling by train, boat or bus; a smaller number had automobiles or even horse-drawn carts.
Genetic variation is increased by meiosis 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.
What is independent assortment and how does it affect the genetic makeup of offspring cells? In meiosis, the random assortment of the alleles at two or more loci. It affects The homologous chromosomes align independently, so each formed gamete has a different combinat â¦ ion of parently and maternal chromosomes.