Origins of replication are best described as what?

• A. Locations where transcription starts
• B. Sites where replication begins
• C. Sites where translation occurs
• D. Sites where DNA is assembled into chromatin

Answer: (B)

Origins of replication are specific genomic locations where DNA replication begins. At these sites, initiator proteins bind and recruit helicase to unwind the DNA, forming replication forks. DNA polymerases then synthesize new strands by adding nucleotides, copying each template strand. In eukaryotes, multiple origins per chromosome ensure the entire genome is replicated efficiently within the cell cycle.

These sites are not where transcription starts (those are promoters), not where translation occurs (ribosomes translate mRNA), and not where DNA is assembled into chromatin (that process involves packaging DNA with histones). So origins of replication are best described as sites where replication begins.