AP BIOLOGY

Detailed explanation-1: -Reason: Chromosomes have specific sequences called ‘ori’ region where DNA replication is initiated.

Detailed explanation-2: -Replication of the bacterial chromosome is initiated at a single oriC region, proceeds in both directions, and terminates at the ter region. During slow growth, replication is initiated once per cell cycle.

Detailed explanation-3: -The ori is the place where DNA replication begins, enabling a plasmid to reproduce itself as it must to survive within cells. The replicons of plasmids are generally different from the those used to replicate the host’s chromosomal DNA, but they still rely on the host machinery to make additional copies.

Detailed explanation-4: -Replication begins at particular positions in chromosomes called “origins” where designated initiator proteins bind to DNA to start the process of replication.

Detailed explanation-5: -When replication starts, an origin of replication forms, consisting of two replication fork(s) moving in opposite directions. DNA double helix is separated into single strands by the enzyme DNA helicase. Newly-exposed, unreplicated DNA is protected by single-strand binding protein.