The stage of the cell cycle where replicated chromosomes line up on the equator of the cell is called metaphase.

Here's a breakdown of the stages of mitosis and what happens during each:

* Prophase: The chromosomes condense and become visible, the nuclear envelope breaks down, and the spindle fibers form.

* Metaphase: The replicated chromosomes line up at the equator of the cell, with each sister chromatid attached to a spindle fiber from opposite poles. This ensures that each daughter cell receives one copy of each chromosome.

* Anaphase: The sister chromatids separate and move to opposite poles of the cell, pulled by the spindle fibers.

* Telophase: The chromosomes arrive at the poles, the nuclear envelope reforms around each set of chromosomes, and the spindle fibers disappear.

* Cytokinesis: The cytoplasm divides, separating the two daughter cells.