Homologous Chromosome Separation in Anaphase I — NEET Biology

Correct answer: B — S3 and S4 only

The core concept here involves distinguishing the events of different stages of meiosis, particularly Anaphase I and Anaphase II, and their comparison with related events. S1: Correct. According to NCERT, in Anaphase I, homologous chromosomes separate, and sister chromatids remain associated at their centromeres. This means the centromeres do not divide. S2: Correct. NCERT states that in Metaphase I, bivalent chromosomes align on the equatorial plate. S3: Incorrect. Meiosis I (primary meiotic division) is a reductional division where homologous chromosomes separate, leading to a reduction in chromosome number. Sister chromatids separate during Meiosis II. S4: Incorrect. In Anaphase II, the centromeres split simultaneously, and sister chromatids separate, moving towards opposite poles. S5: Correct. NCERT mentions that interkinesis is a short-lived stage between Meiosis I and Meiosis II, and no DNA replication occurs during this period. S6: Correct. Diakinesis, the final stage of Prophase I, is characterized by the terminalisation of chiasmata and full condensation of chromosomes. Therefore, statements S3 and S4 are NOT correct. Recap: The question tests the accurate identification of events during different meiotic stages, specifically focusing on chromosome and centromere behaviour, and the nature of Meiosis I and II.