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.
The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes. The principle of independent assortment states that genes for different traits can segregate independently during the formation of gametes. Independent assortment helps account for the many genetic variations observed in plants,animals, and other organisms.