Explain why dna replication cannot proceed to the regions of the chromosome labeled as i in figure 1b unless topoisomerase binds ahead of each advancing replication fork in region ii.

Abacterium was found to contain a sequence of atcgggatcct in its genome. a few generations later, the sequence was found to be atcatcct. what type of mutation caused this change in the bacteria? a. duplication b. insertion c. inversion d. translocation