what is constriction formation
Answers
Explanation:
Secondary constriction can be found at a chromosome in addition to primary constriction/centromere. Chromosomes can bend only at the site of primary constriction during Anaphase. Secondary constrictions are useful in identifying a chromosome from a set.
Actually centromere ( as it plays most important role in chromatid separation during anaphase ) is present within the primary constriction. Primary constriction is present in all chromosomes . But secondary constriction is not present in all chromosomes. Secondary constriction is also known as nucleolar organizer region as NOR is involved in the formation of nucleolus. The location of NOR or Secondary constriction is species specific as it plays most important role in karyosystematics or karyology and cytotaxonomy.