centromere

noun Cell Biology.

1. a specialized structure on the chromosome, appearing during cell division as the constricted central region where the two chromatids are held together and form an X shape.

noun

1. the dense nonstaining region of a chromosome that attaches it to the spindle during mitosis

n.

1. The most condensed and constricted region of a chromosome to which the spindle fiber is attached during mitosis.kinetochore

1. The region of the chromosome to which the spindle fiber is attached during cell division (both mitosis and meiosis). The centromere is the constricted point at which the two chromatids forming the chromosome are joined together. See more at meiosis mitosis.