Meiosis and fertilization allow traits to be present in many different combinations to produce genetic variation. During meiosis, the sperm or egg cell (gametes) combine by crossing over and the number of chromosomes is restored during fertilization.
In humans, meiosis is a division process from a diploid cell that is one with two sets of chromosomes to haploid cells, which ones with a single set of chromosomes. These chromosomes contains alternate forms of genes, which is two alleles for each inherited trait and each allele comes from each parent. This alternative form of a single gene passed down from generation to generation and the combination of chromosomes during meiosis and fertilization results to the diversity of human traits.
They allow for traits to be present in many different combinations.
