What process begins at origins of replication in the middle of a DNA molecule?

What process begins at origins of replication in the middle of a DNA molecule?

• A. Transcription
• B. Translation
• C. DNA replication
• D. DNA repair

Answer: (C)

Initiation of DNA replication occurs at origins of replication. These are specific DNA sequences where initiator proteins gather and recruit helicase to unwind the double helix, creating replication forks that move outward. From there, primase lays down RNA primers to provide a 3' end for DNA polymerases to extend, and DNA polymerases synthesize the new strands in the 5' to 3' direction, using the old strands as templates. This process is semiconservative, meaning each new DNA molecule contains one old strand and one new strand. In many organisms, replication starts at multiple origins and proceeds bidirectionally, so the molecule is copied efficiently from the middle outward. This is distinct from transcription (making RNA from DNA), translation (protein synthesis from mRNA), and DNA repair (fixing damaged DNA).

Initiation of DNA replication occurs at origins of replication. These are specific DNA sequences where initiator proteins gather and recruit helicase to unwind the double helix, creating replication forks that move outward. From there, primase lays down RNA primers to provide a 3' end for DNA polymerases to extend, and DNA polymerases synthesize the new strands in the 5' to 3' direction, using the old strands as templates. This process is semiconservative, meaning each new DNA molecule contains one old strand and one new strand. In many organisms, replication starts at multiple origins and proceeds bidirectionally, so the molecule is copied efficiently from the middle outward. This is distinct from transcription (making RNA from DNA), translation (protein synthesis from mRNA), and DNA repair (fixing damaged DNA).