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.
(In a more speciDc sense, assortment refers to the random distribution of genes located on different chromosomes.) i Ã¯ since each homologous pair assorts independently from all the, others the process produces 2n possible combinations of maternal and paternal chromosomes in, gametes where n is the haploid. numberrossing over = The exchange of genetic material between homologues; occurs during prophase of meiosis 1. This process: i Ã¯ occurs when homologous portions of two nonsister chromatids trade. Places during Prophase, I-x shaped chiasmata become visible at places where this homologous strand exchange. occurs