text: Verification of kinetochore–MT anchoring During S-Phase, the cell duplicates all the genetic information stored in the chromosomes, in the process termed DNA replication. At the end of this process, each chromosome includes two sister chromatids, which are two complete and identical DNA molecules. Both chromatids remain associated by cohesin complexes until anaphase, when chromosome segregation occurs. If chromosome segregation happens correctly, each daughter cell receives a complete set of chromatids, and for this to happen each sister chromatid has to anchor (through the corresponding kinetochore) to MTs generated in opposed poles of the mitotic spindle. This configuration is termed amphitelic or bi-orientation.
  However, during the anchoring process some incorrect configurations may also appear:
  monotelic: only one of the chromatids is anchored to MTs, the second kinetochore is not anchored; in this situation, there is no centromeric tension, and the spindle checkpoint is activated, delaying entry in anaphase and allowing time for the cell to correct the error. If it is not corrected, the unanchored chromatid might randomly end in any of the two daughter cells, generating aneuploidy: one daughter cell would have chromosomes in excess and the other would lack some chromosomes.
  syntelic: both chromatids are anchored to MTs emanating from the same pole; this situation does not generate centromeric tension either, and the spindle checkpoint will be activated. If it is not corrected, both chromatids will end in the same daughter cell, generating aneuploidy.
  merotelic: at least one chromatid is anchored simultaneously to MTs emanating from both poles. This situation generates centromeric tension, and for this reason the spindle checkpoint is not activated. If it is not corrected, the chromatid bound to both poles will remain as a lagging chromosome at anaphase, and finally will be broken in two fragments, distributed between the daughter cells, generating aneuploidy.