Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

During which phase of mitosis do duplicated chromosomes line up along the metaphase plate?

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

The correct answer is: Metaphase

During mitosis, the phase in which duplicated chromosomes line up along the metaphase plate is called metaphase. This stage is characterized by the alignment of chromosomes in the middle of the cell, ensuring that, as the process continues, each daughter cell will receive an identical set of chromosomes. In metaphase, the chromosomes, which have already been duplicated during the previous stage (interphase), are attached to spindle fibers at their centromeres, holding them in place along the equatorial plane of the cell. This alignment is critical for the accurate separation of the chromosomes that will take place in the next phase, anaphase. Proper alignment and attachment are essential to prevent errors in chromosome distribution, which could lead to conditions such as aneuploidy in the resulting daughter cells. Understanding the actions occurring during metaphase reinforces the importance of this phase in the overall process of cell division and the maintenance of genetic stability in organisms.