Humber Admissions Practice Test

During which phase of mitosis do chromosomes align in the center of the cell?

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

The correct answer is: Metaphase

During metaphase, chromosomes align at the equatorial plane, often referred to as the metaphase plate, in the center of the cell. This alignment is crucial because it ensures that each daughter cell will receive an identical set of chromosomes during cell division. The spindle fibers, which are structures that help segregate the chromosomes, attach to the centromeres of the chromosomes at this stage. Proper alignment ensures that the genetic material is evenly distributed, reducing the risk of errors such as aneuploidy, where cells have an abnormal number of chromosomes. In contrast, during prophase, chromosomes condense and become visible, but do not yet align. Anaphase involves the separation and movement of the sister chromatids to opposite poles of the cell, while telophase marks the end of mitosis where nuclear envelopes reform around the separated chromosomes, but the chromosomes are not aligned in the center at this point. This makes the alignment during metaphase a critical step in successfully completing mitosis and ensuring genetic stability in the daughter cells.