The mechanism by which DNA is licensed to replicate only once during each S phase involves
A)CENP-A binding to CEN DNA.
B)MCM proteins binding only to CEN DNA.
C)MCM proteins binding only to replicated DNA.
D)MCM proteins binding only to nonreplicated DNA.
E)MCM proteins binding to both replicated and nonreplicated DNA.

Question

Quizplus · Accepted Answer

MCM proteins are essential for ensuring that DNA replication occurs only once per cell cycle. They bind to nonreplicated DNA, marking it as ready for replication. Once DNA has been replicated, MCM proteins are displaced or modified to prevent re-replication, ensuring that each segment of DNA is replicated only once during the S phase.

The Mechanism by Which DNA Is Licensed to Replicate Only