Meiosis

Diploid to Haploid

Crossing Over Synapsis- Homologous Pairs line up = Tetrad During synapsis the chromstids within a homologous pair may twist around each other and break off and attach to the other homologous pair = Crossing Over Results in exchange of genetic material between maternal and paternal chromosomes = genetic recombination

Law of Independent Assortment During metaphase, as the homologous pairs line up the orientation of maternal and paternal chromosomes is random Not all maternal go to one side, and paternal the other….it is mixed Law of independent assortment As the homologous pairs are separated in anaphase, they maternal and paternal chromosomes have random separation Results in genetic variation

Law of Independent Assortment

Formation of Gametes Meiosis only occurs in the reproductive cells…all other cells undergo mitosis Ending products of meiosis are haploid gametes Eggs in female - oogenesis Sperm in male - spermatogenesis Fusion of sperm and egg results in a diploid cell

DNA v. Gene

Karyotype 46 chromosomes, 23 pair One of each pair was from mom, one from dad