<prompt> Crossing over, true is;Occurs during diplotene stageBetween non sister chromatids of homologous chromosomesBetween sister chromatids of homologous chromosomesBetween non homologous chromosomes sister chromatids  <response>: Crossing over is the exchange of genetic material between non sister chromatids of homologous chromosomes occuring during pachytene stage of prophase I of meiosis.Recombination of genes in the same chromosome is brought about by crossing over. Ref: PRINCIPLES OF GENETICS, By Eldon John Gardner, Michael J. Simmons, D. Peter Snustad, 8th Edition, Page 163 