Final answer:
In Prophase II of Meiosis II, chromosomes, each with two sister chromatids, become visible but do not pair to form tetrads. This is because homologous chromosomes were separated during Meiosis I, leading to the production of haploid gametes at the end of Meiosis II.
Step-by-step explanation:
During Prophase II, their chromosomes, each consisting of two sister chromatids, become visible. The chromosome do not pair to form tetrads because the homologous pairs were already separated during Meiosis I.
In Meiosis I, specifically during Prophase I, homologous chromosomes pair up to form tetrads and crossing-over occurs, which is unique to this phase. However, in Meiosis II, following the separation of homologous chromosomes during Anaphase I, the sister chromatids are not paired with their homologous counterparts because they have been divided into different cells. Consequently, they do not form tetrads in Prophase II and are prepared for separation into individual chromosomes during the subsequent phases of Meiosis II. This leads to the production of haploid gametes, each with a unique genetic composition.
Remember that at the end of Meiosis II, four different gametic combinations are produced, each containing a haploid set of chromosomes.