 This motor activity, coupled with polymerisation and depolymerisation of microtubules, provides the pulling force necessary to later separate the chromosome's two chromatids.After the microtubules have located and attached to the kinetochores in prometaphase, the two centrosomes begin pulling the chromosomes towards opposite ends of the cell.The resulting tension causes the chromosomes to align along the "metaphase plate" or "equatorial plane", an imaginary line that is centrally located between the two centrosomes (at approximately the midline of the cell).