Which of the following options gives the correct sequence of events during mitosis?
Answer: (B) Condensation → nuclear membrane disassembly → arrangement at equator → centromere division → segregation → telophase. Answer: Condensation → nuclear membrane disassembly → arrangement at equator → centromere division → segregation → telophase Solution: Mitosis proceeds as chromosomal condensation (prophase) → disassembly of the nuclear envelope → alignment of chromosomes at the equator/metaphase plate (metaphase) → splitting of centromeres (anaphase) → segregation of chromatids to poles → telophase.
- A.Condensation → nuclear membrane disassembly → crossing over → segregation → telophase
- B.Condensation → nuclear membrane disassembly → arrangement at equator → centromere division → segregation → telophase✓
- C.Condensation → crossing over → nuclear membrane disassembly → segregation → telophase
- D.Condensation → arrangement at equator → centromere division → segregation → telophase
Correct Answer
(B) Condensation → nuclear membrane disassembly → arrangement at equator → centromere division → segregation → telophase
Solution & Explanation
Answer: Condensation → nuclear membrane disassembly → arrangement at equator → centromere division → segregation → telophase Solution: Mitosis proceeds as chromosomal condensation (prophase) → disassembly of the nuclear envelope → alignment of chromosomes at the equator/metaphase plate (metaphase) → splitting of centromeres (anaphase) → segregation of chromatids to poles → telophase. Options containing 'crossing over' are wrong because crossing over is a meiotic event and does not occur in mitosis. Only option B keeps centromere division and equatorial alignment in the correct mitotic order. NCERT Reference: Ch 10, p.123, lines 20-21 — "all the chromosomes coming to lie at the equator"