Question

when a double helix of dna is replicated, two complete helices are formed. together, these helices are called sister ______.

○ telomeres
○ chromosomes
○ centromeres
○ chromatids

Explanation:

To solve this, we analyze each option:

• Telomeres: Regions at chromosome ends, not related to DNA replication products.
• Chromosomes: A replicated chromosome has two sister chromatids, but the term for the two helices after replication is sister chromatids, not chromosomes.
• Centromeres: The region where chromatids are attached, not the replicated DNA helices.
• Chromatids: During DNA replication, the original DNA helix and the newly synthesized one (each a chromatid) are sister chromatids, forming two complete helices.

Answer:

D. chromatids