During which phase do chromosomes line up in the middle of the cell?

During which phase do chromosomes line up in the middle of the cell?

• A. Interphase
• B. Prophase
• C. Metaphase
• D. Telophase

Answer: (C)

Chromosome alignment in the center happens during metaphase. In this stage, the condensed chromosomes line up along the equatorial plane, the metaphase plate, as microtubules from opposite spindle poles attach to the kinetochores of each chromosome. The tension from these attachments pulls sister chromatids into a single, central row, ready to separate in the next phase. This positioning ensures that when the chromatids are pulled apart, each new daughter cell will receive an identical set. Earlier in the cycle, chromosomes are not yet condensed and mitotic spindles aren’t fully formed (interphase), and during prophase the chromosomes condense and the nuclear envelope breaks down, while in telophase the chromosomes arrive at the poles and de-condense.

Chromosome alignment in the center happens during metaphase. In this stage, the condensed chromosomes line up along the equatorial plane, the metaphase plate, as microtubules from opposite spindle poles attach to the kinetochores of each chromosome. The tension from these attachments pulls sister chromatids into a single, central row, ready to separate in the next phase. This positioning ensures that when the chromatids are pulled apart, each new daughter cell will receive an identical set. Earlier in the cycle, chromosomes are not yet condensed and mitotic spindles aren’t fully formed (interphase), and during prophase the chromosomes condense and the nuclear envelope breaks down, while in telophase the chromosomes arrive at the poles and de-condense.