(1) Chromosome loss may be the result of either non-attachment of the chromosome kinetochore to the spindle microtubules or chromosome lagging at anaphase and gives rise to a micronucleus.(2) The DNA is asymmetrically distributed to the daughter cells when the kinetochores do not attach and the spindle checkpoint does not restrain mitosis.(3) This cohesion or ‘chiasma binder’ function ensures the generation of a bipolar spindle in which tension is generated at the kinetochores .(4) In metaphase, sister kinetochores attach to microtubules emanating from opposite spindle pole bodies during alignment of the chromosomes.(5) A second checkpoint pathway, the spindle checkpoint, operates at a similar point in meiosis, preventing progression into anaphase if the spindle apparatus fails to connect appropriately with kinetochores .