Final answer:
The monopolar arrangement of sister chromatids in meiosis I allows for genetic diversity and the production of unique gametes. Homologous chromosomes undergo synapsis and crossing over during prophase I, resulting in recombinant chromatids. In metaphase I, the replicated chromosomes align randomly along the equator for independent assortment. Finally, separation of sister chromatids occurs during anaphase II of meiosis II, producing four different gametic combinations.
Step-by-step explanation:
The reason for the monopolar arrangement of sister chromatids in meiosis I is to ensure genetic diversity and the production of unique gametes. During prophase I, homologous chromosomes pair up in a process called synapsis. Within this pair, non-sister chromatids undergo crossing over, exchanging genetic material.
During metaphase I, the replicated chromosomes align randomly along the equator of the cell. This random alignment, known as independent assortment, leads to different combinations of maternal and paternal chromosomes being pulled to opposite poles of the cell during anaphase I. Finally, separation of sister chromatids occurs during anaphase II of meiosis II, resulting in four different gametic combinations, each containing a haploid set of chromosomes.