Exam 20: Dna Replication,damage and Repair

Which of the following agents causes DNA damage by forming pyrimidine dimers?

Double stranded DNA breaks caused by ionizing radiation are the least dangerous type of DNA damage due to repair by homologous recombination.

By _____________ the adenine found in the sequence GATC on the parental DNA strand,E.coli is able to differentiate the parental strand from the mismatched base pairs in the daughter strand.

The discovery of _________ fragments helped prove the semidiscontinuous nature of DNA replication.

The fact that rifampicin inhibits M13 phage replication helped support the fact that

DNA damage is considered to be the same thing as a DNA mutation,such as a change from an A-T base pair to a G-C base pair.

Which of the following repair mechanisms is a damage bypass mechanism,not an actual repair mechanism?

DNA under the control of one origin of replication is called a replicon.

E.coli DNA Polymerase III does not have perfect fidelity.This is a beneficial characteristic since mutations help the cell adapt to changing environments.

The enzyme responsible for bacterial DNA replication is _________.

$\lambda$ phage replicates its genome using unidirectional DNA replication.

In E.coli,the antibiotic nalidixic acid prevents DNA replication by inhibiting DNA gyrase,which then causes positive supercoiling of the DNA.

The $\varepsilon$ -subunit of DNA Polymerase III core enzyme functions in proofreading by having 5 $\rightarrow$ 3' exonuclease activity.