In E. coli, replication begins at which chromosome site?
A.The replication fork
B.Hfr
C.oriC
D.TATA box
E.Pribnow box
To answer this question, you need to have some knowledge of the DNA replication process in E. coli. Here's an explanation of each option and how to arrive at the correct answer:
A. The replication fork: The replication fork is not a specific site on the chromosome where replication begins, but rather a structure that forms during DNA replication as the DNA strands separate.
B. Hfr: Hfr refers to a specialized condition in bacterial cells where the F factor (fertility factor) that controls conjugation becomes integrated into the bacterial chromosome. While Hfr cells can initiate replication at various points, it does not specify a particular site on the chromosome where replication begins.
C. oriC: oriC stands for the origin of replication in E. coli, and it is the specific site on the chromosome where replication begins. It contains specific DNA sequences recognized by replication initiation proteins.
D. TATA box: The TATA box is a DNA sequence commonly found in eukaryotic genes. It is not relevant to the replication initiation in E. coli.
E. Pribnow box: The Pribnow box, also known as the -10 element, is a DNA sequence found in bacterial promoter regions and is recognized by RNA polymerase during transcription. It does not relate to replication initiation.
Considering the explanations above, the correct answer to the question is C. oriC, as it is the specific site on the E. coli chromosome where replication begins.