Final answer:
DNA polymerase III is the primary enzyme for DNA synthesis in E. coli, continuously creating new strands of DNA. DNA polymerase I is responsible for replacing RNA primers with DNA on the lagging strand. The correct answer to the contrast between these enzymes is that DNA polymerase I removes RNA primers and DNA polymerase III synthesizes both strands. Option D is correct.
Step-by-step explanation:
During E. coli DNA replication, DNA polymerase III is the main enzyme responsible for adding nucleotides and synthesizing a new strand of DNA. When replication begins, an enzyme called primase synthesizes an RNA primer. DNA polymerase III uses this primer to start the synthesis of the daughter DNA strand.
On the leading strand, DNA is synthesized continuously. On the lagging strand, DNA is synthesized in short sections known as Okazaki fragments. Once the fragments are created, DNA polymerase I plays a critical role by removing the RNA primers used to initiate the synthesis of the Okazaki fragments and replaces them with DNA. Finally, DNA ligase Seals the breaks between the Okazaki fragments, forming a continuous strand of DNA.
The correct answer to the question of contrasting the role of DNA polymerase I and III in E. coli DNA replication is option D) DNA polymerase I removes RNA primers; DNA polymerase III synthesizes both strands continuously.