Replication proceeds in what manner from origins?

Replication proceeds in what manner from origins?

• A. In both directions from each origin.
• B. In one direction.
• C. From one end toward the center.
• D. Inward only.

Answer: (A)

Replication begins at origins and proceeds bidirectionally from each origin. At an origin, initiator proteins recruit helicases to unwind the DNA, creating a replication bubble with two replication forks. DNA polymerases then synthesize new strands in the 5' to 3' direction on both templates, so the forks move away from the origin in opposite directions. In a bacterial chromosome, a single origin yields two forks that travel in opposite directions around the circle; in eukaryotic genomes, many origins fire to form multiple bubbles. This bidirectional progression is why replication from origins covers the genome efficiently.

Replication begins at origins and proceeds bidirectionally from each origin. At an origin, initiator proteins recruit helicases to unwind the DNA, creating a replication bubble with two replication forks. DNA polymerases then synthesize new strands in the 5' to 3' direction on both templates, so the forks move away from the origin in opposite directions. In a bacterial chromosome, a single origin yields two forks that travel in opposite directions around the circle; in eukaryotic genomes, many origins fire to form multiple bubbles. This bidirectional progression is why replication from origins covers the genome efficiently.