A research project using E coli has come to a halt because DNA replication is blocked. It that the DNA strands are not separating. What enzyme is likely faulty? A. Helicase (DNA B protein) B. Topoisomerase I C. DNA ligase D. One of DNA primases E. DNA polymerase I DNA must be replicated with extremely high fidelity, and maintained free of structural acts in order to propagate a species. Which of the following structural changes in DNA, damage, cannot be repaired? A. Pyrimidine dimers B. Mismatched bases C. Methylation of bases, such as 1-methylguanine or 3-methycytosine D. Uracil or incorporated into DNA E. All of the above can be repaired. DNA may be repaired by removing a mutation and replacing it, so-called excision repair. such of the following mutations can actually be repaired directly by a mechanism requiring A. pyrimidine dimers B. Mismatched bases C. Methylation of bases, such as 1-methyguanine or 3-methycytosine D. Uracil incorporated into DNA E. Depuration A genomic DNA segment may be spontaneously removed and inserted into another location of the same chromosome. What is the name of this process, discovered by Barbara McClintock? A. Conjugation B. Transposition C. SOS response E. Cointegration A DNA segment was isolated and analyzed. It actually contained 3 DNA strands held together by a protein polymer. The polymer appeared to be filamentous but was later found to assist with location of homogeneous DNA sequences. What is the most likely protein serving these roles?