Genetic consequence of meiosis
Humans and other complex multicellular organisms reproduce sexually because this ensures genetic variation in the population. By producing gametes through meiosis rather than mitosis, the offspring inherits the correct number of chromosomes once the sperm and egg fuse during fertilization. It also ensures that each gamete is unique.
Each gamete is genetically unique because of the random assortment of paternal and maternal homologs and because of the recombination of maternal and paternal segments of chromosomes—with their sets of genes—that occurs during crossover (Figure 1).
Figure 1. Random Assortment of paternal and maternal homologs.
Let’s use an example image with two chromosomes (n=2) undergoing independent assortment at metaphase
To demonstrate randomness, independent assortment at metaphase