Fig. 7: Diagram to illustrate the essential features of meiosis and show how a reduction in chromosome number and a reshuffling of segments of homologous chromosomes is achieved. Two homologous chromosomes have been shown differentiated (solid and outline) for clarity, a, pachytene, showing the synapsed homologous chromosomes, each of the chromatids: the break in two non-sister chromatids represents the region of one cross-over, b, diplotene showing one chiasma as an exchange between non-sister chromatids. c-e, stages of anaphase I showing progressive terminalization of the chiasma. f, anaphase II, showing one chromosome at each pole: two chromosomes are parental, two are recombinants, the latter having arisen through the exchange of segments at crossing-over.