Kaplan Nursing Entrance Practice Exam

During mitosis, which phase is characterized by the alignment of chromosomes?

1. Prophase

2. Metaphase

3. Telophase

4. Interphase

The correct answer is: Metaphase

The phase of mitosis characterized by the alignment of chromosomes along the metaphase plate is metaphase. During this stage, the chromatid pairs, which have already been duplicated and condensed, are organized to ensure that each daughter cell will receive an identical set of chromosomes. The spindle fibers, which are formed during prophase, attach to the centromeres of the chromosomes, pulling them into alignment at the cell's equator. This alignment is crucial because it helps facilitate the accurate segregation of chromosomes when the cell divides. Proper alignment ensures that each new cell will inherit the correct number of chromosomes, preventing genetic abnormalities. In contrast, prophase involves the condensation of chromatin into visible chromosomes and formation of the spindle apparatus, but it does not involve alignment. Telophase occurs after metaphase and involves the de-condensation of chromosomes and the formation of the nuclear membrane around each set of chromosomes. Interphase is the phase when the cell is preparing to divide but is not a stage of mitosis. Hence, metaphase is the correct answer as it directly pertains to the specific alignment of chromosomes.