What are the Cellular Mechanisms That Must Fail Before a DNA

Question

What are the cellular mechanisms that must fail before a DNA replication error becomes a mutation?  
A) translation and transcription
B) transcription and proofreading
C) proofreading and repair
D) replication and translation
E) replication and repair

Accepted Answer

The cellular mechanisms that must fail before a DNA replication error becomes a mutation are proofreading and repair. Proofreading is the process by which DNA polymerase checks for and corrects errors during replication while repair is the mechanism by which cells detect and fix DNA damage. When both these mechanisms fail, replication errors become permanent mutations in the DNA sequence. Translation and transcription refer to processes involved in gene expression, and are not directly related to replication errors. Replication and repair are directly involved in preventing replication errors from becoming mutations, rather than being mechanisms that can fail after an error has already occurred.