This doubles the variability of gamete genotypes. Near the end of Prophase I, the homologous chromosomes begin to separate slightly, although they remain attached at chiasmata. Image from W.H. Freeman and Sinauer Associates, used by permission. Image from W.H. Freeman and Sinauer Associates, used by permission. I is when tetrads line-up along the equator of the spindle.
Spindle fibers attach to the centromere region of each homologous chromosome pair.
Other metaphase events as in mitosis. I is when the tetrads separate, and are drawn to opposite poles by the spindle fibers. The centromeres in Anaphase I remain intact. Image from W.H. Freeman and Sinauer Associates, used by permission. Depending on species, new nuclear envelopes may or may not form.