We briefly mentioned the trombone model of DNA replication, which describes formation of a large loop during DNA replication. Which of the following is TRUE of E. coli DNA replication, including the trombone model? (Hint: see figures 11-21 and 11-22 of the textbook.) Only dsDNA is found in the loop. A loop forms on the leading strand. Only one DNA polymerase III can participate in replication. There are sometimes two loops formed on the lagging strand. .