Duplicated chromosomes line up across the center of the cell during metaphase, the fourth stage of mitosis.

Here's why:

* Mitosis is the process of cell division that produces two identical daughter cells.

* Metaphase is the stage where the replicated chromosomes, each consisting of two identical sister chromatids, align themselves along the center of the cell, forming the metaphase plate.

* This alignment is crucial for ensuring that each daughter cell receives a complete set of chromosomes.

Let me know if you have any other questions about cell division!