During prophase 1, chromosomal crossing over takes place, in which genetic information is exchanged between chromatids of each homologous pair of chromosomes in their bivalents- the point of crossing over is the chiasma. This leads to genetic diversity as the chromosomes now have a different combination of alleles. During metaphase 1, independent assortment of chromosomes takes place. The orientation of each homologous pair on the metaphase plate is random- the maternal and paternal chromosome could end up facing either pole.