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.
Independent assortment of chromosomes is a result of. A. the random and independent way in which each pair of homologous chromosomes lines up at the metaphase plate during meiosis I. B. the random nature of the fertilization of ova by sperm. C. the relatively small degree of homology shared by the X and Y chromosomes.