metaphase orientation of the chromosomes may be explained as the resultant of two forces : a force involving the centromere and spindle , which is responsible for keeping the centromeres in the equatorial plane of the spindle , and a repulsion force involving the noncentromeric portion of the chromosomes , which results in a tendency toward uniform spacing of the chromosomes outside the spindle .
C0007709
centromeres
C0008633
chromosomes