What structure is created when a chromosome has been replicated and remains joined at the centromere?

What structure is created when a chromosome has been replicated and remains joined at the centromere?

• A. Sister chromatids
• B. Homologous chromosomes
• C. A single chromatid
• D. Two sister chromatids

Answer: (D)

After DNA replication, each chromosome is copied, producing two identical DNA molecules that stay attached at the centromere. This arrangement forms two sister chromatids, which together make a single duplicated chromosome. The sister chromatids remain connected until they are pulled apart during cell division, ensuring that each new cell gets a full set of genetic information. A single chromatid would be just one copy, not the replicated pair; homologous chromosomes are the matching chromosomes from each parent, not the two copies of the same chromosome; and two separate chromatids would imply they’re no longer held together at the centromere.

After DNA replication, each chromosome is copied, producing two identical DNA molecules that stay attached at the centromere. This arrangement forms two sister chromatids, which together make a single duplicated chromosome. The sister chromatids remain connected until they are pulled apart during cell division, ensuring that each new cell gets a full set of genetic information. A single chromatid would be just one copy, not the replicated pair; homologous chromosomes are the matching chromosomes from each parent, not the two copies of the same chromosome; and two separate chromatids would imply they’re no longer held together at the centromere.