Question

Formation of recombination nodules is characteristic of the ______ stage of meiosis I.

• A. zygotene
• B. leptotene
• C. pachytene
• D. diakinesis

Answer 1

The correct option is C pachytene

Prophase I of meiosis I is a unique phase which involves recombination of genetic material between homologous chromosomes. This occurs in the pachytene stage where the non-sister chromatids of the homologous chromosomes cross-over and exchange of genetic material takes place. Recombination nodules are the sites at which the non-sister chromatids crossover.


Leptotene and zygotene occur before pachytene and here the chromosomes become compact and the homologous chromosomes start pairing up during meiosis I.

Diakinesis occurs after pachytene and is characterized by the separation of the homologous chromosomes.