A centromere is a region on a chromosome that joins two sister chromatids.

In prophase of mitosis, kinetochore fibers attach to the centromeres of the chromosomes.

During metaphase, kinetochore fibers attach to polar spindle fibers at the centromere region. Both types of fibers help to align the chromosomes along the metaphase plate.

For more information, see:

• Cell Biology Glossary