AP BIOLOGY

Detailed explanation-1: -DNA replication begins at a single origin of replication, and the two replication forks assembled there proceed (at approximately 500–1000 nucleotides per second) in opposite directions until they meet up roughly halfway around the chromosome (Figure 5-30).

Detailed explanation-2: -DNA replication initiates at specific points, called origins, where the DNA double helix is unwound. A short segment of RNA, called a primer, is then synthesized and acts as a starting point for new DNA synthesis. An enzyme called DNA polymerase next begins replicating the DNA by matching bases to the original strand.

Detailed explanation-3: -DNA replication cannot be initiated randomly at any place in the DNA. There are definite regions which act as sites for the initiation of the process of replication. These sites are also known as Origin of Replication.

Detailed explanation-4: -Replication always starts at specific locations on the DNA, which are called origins of replication and are recognized by their sequence. E. coli, like most bacteria, has a single origin of replication on its chromosome.

Detailed explanation-5: -Genome duplication is carried out by pairs of replication forks that assemble at origins of replication and then move in opposite directions. DNA replication finishes when converging replication forks meet.