Final answer:
The origin of replication in the E. coli chromosome, called oriC, is rich in AT sequences and serves as the starting point for DNA replication. Proteins bind to the origin of replication and helicase unwinds the DNA to form replication forks.
Step-by-step explanation:
The origin of replication in the E. coli chromosome, called oriC, is characterized as being rich in adenine-thymine (AT) sequences. The origin of replication is approximately 245 base pairs long and serves as the starting point for DNA replication in E. coli. Certain proteins bind to the origin of replication, and the enzyme helicase unwinds the DNA to form replication forks. Single-strand binding proteins prevent the DNA from rewinding into a double helix.