Final answer:
In the post-crossing over phase of meiosis, the homologous chromosomes are connected at chiasmata by four chromatids forming a structure known as a tetrad.After the process of crossing over is complete in meiosis, the homologous chromosomes remain attached at specific points known as chiasmata.
Step-by-step explanation:
After the process of crossing over is complete in meiosis, the homologous chromosomes remain attached at specific points known as chiasmata. A structure referred to as a tetrad forms, which consists of two duplicated homologous chromosomes. Each homologous chromosome consists of two sister chromatids, therefore, a total of four chromatids are attached at each chiasma.
Recombination nodules along the synaptonemal complex during prophase I indicate the spots of chiasmata where crossing over occurs between non-sister chromatids. At this stage, chromosomes condense further and the nuclear envelope disappears, resulting in the chromosomes being attached to spindle microtubules at the fused kinetochores shared by the sister chromatids. It is crucial that at least one chiasma forms per chromosome to ensure proper separation of homologous chromosomes during anaphase I of meiosis.