During meiosis, variation in the daughter nuclei is introduced because of crossover in prophase I and random alignment of tetrads at metaphase I. Sexual reproduction requires that diploid organisms produce haploid cells that can fuse during fertilization to form diploid offspring.

Meiosis is a series of events that arrange and separate chromosomes and chromatids into daughter cells. The cells that are produced by meiosis are genetically unique

meiosis — a nuclear division process that results in four haploid cells. meiosis I — first round of meiotic cell division; referred to as reduction division because the ploidy level is reduced from diploid to haploid. crossover — exchange of genetic material between non-sister chromatids resulting in chromosomes that incorporate genes from both parents of the organism. tetrad — two duplicated homologous chromosomes (four chromatids) bound together by chiasmata during prophase I.