The process of appearance of recombination nodules occurs at which sub stage of prophase I in meiosis?
Answer: (B) Pachytene. Answer: Pachytene Solution: Recombination nodules appear during the pachytene stage of prophase I; these are the sites at which crossing over occurs between non-sister chromatids of homologous chromosomes.
- A.Zygotene
- B.Pachytene✓
- C.Diplotene
- D.Diakinesis
Correct Answer
(B) Pachytene
Solution & Explanation
Answer: Pachytene Solution: Recombination nodules appear during the pachytene stage of prophase I; these are the sites at which crossing over occurs between non-sister chromatids of homologous chromosomes. Zygotene is marked by synapsis and synaptonemal complex formation, diplotene by dissolution of the synaptonemal complex and appearance of chiasmata, and diakinesis by terminalisation of chiasmata — so none of these is the stage of recombination nodule appearance. NCERT Reference: Ch 10, p.126, lines 56-59 — "appearance of recombination nodules, the sites at which crossing over occurs"