What is the condensed and constricted region of a chromosome where sister chromatids attach during cell division?

What is the condensed and constricted region of a chromosome where sister chromatids attach during cell division?

• A. Telomere
• B. Centromere
• C. Kinetochores
• D. Chromatid

Answer: (B)

The key idea here is the part of a chromosome that holds the two sister chromatids together and provides the attachment point for the spindle during division. This region is the centromere. It appears as the narrowed, constricted section of a condensed chromosome, and cohesion proteins keep the sister chromatids linked there after DNA replication. During mitosis, kinetochores—protein complexes that assemble at the centromere—attach to spindle microtubules and drive the coordinated separation of the chromatids in anaphase. Telomeres, on the other hand, are protective ends of the chromosome; a chromatid is one copy of the replicated chromosome, not the attachment site.

The key idea here is the part of a chromosome that holds the two sister chromatids together and provides the attachment point for the spindle during division. This region is the centromere. It appears as the narrowed, constricted section of a condensed chromosome, and cohesion proteins keep the sister chromatids linked there after DNA replication. During mitosis, kinetochores—protein complexes that assemble at the centromere—attach to spindle microtubules and drive the coordinated separation of the chromatids in anaphase. Telomeres, on the other hand, are protective ends of the chromosome; a chromatid is one copy of the replicated chromosome, not the attachment site.