Which process features a spindle with Aurora B kinase localized and chromosomes aligning on a metaphase plate, before cytokinesis?

• A. Meiosis
• B. Interphase
• C. Cytokinesis
• D. Mitosis

Answer: (D)

The event described centers on the orderly division of the nucleus during mitosis. A spindle assembles and Aurora B kinase, part of the chromosomal passenger complex, localizes to chromosomes to monitor and correct attachments as they condense and align. The chromosomes then line up along the metaphase plate in preparation for separation. Only after this alignment does the cell move on to anaphase and then cytokinesis to finish dividing the cell. This sequence—spindle formation with Aurora B activity, alignment of chromosomes at the metaphase plate, followed by cytokinesis—fits mitosis precisely. Interphase lacks a mitotic spindle and metaphase, meiosis involves an additional division and different chromosome dynamics, and cytokinesis is the final splitting of the cell after mitosis.