During a specific stage of meiosis, the exchange of genetic material actively occurs between the non-sister chromatids of homologous chromosomes. Which specific morphological structure marks the exact site where this exchange takes place?

Step-by-step solution

The exchange of genetic material between non-sister chromatids of homologous chromosomes is a process known as crossing over. According to NCERT, crossing over occurs during the pachytene stage of prophase I. This stage is characterised by the appearance of recombination nodules, which are the specific morphological structures that mark the exact sites where crossing over takes place. The synaptonemal complex is a protein scaffold formed earlier during zygotene to pair homologous chromosomes. Chiasmata are X-shaped