Centromeres are specialized regions of chromosomes that play a crucial role during cell division. They are the points where sister chromatids, which are identical copies of a chromosome, are held together. During mitosis and meiosis, centromeres ensure that each new cell receives the correct number of chromosomes by facilitating the proper separation of sister chromatids. The structure of a centromere is unique, often consisting of repetitive DNA sequences. This region is also where the kinetochore forms, a protein complex that attaches to spindle fibers during cell division. This attachment is essential for the movement of chromosomes to opposite poles of the cell, ensuring accurate genetic distribution.