Question

Identify the various types of DNA repair mechanisms known to counteract the effects of UV radiation. Recombinational repair Excision repair Photoactivation repair SOS repair 1. is dependent on a photon-activated enzyme that cleaves thymine dimers. 2. is the process by which an endonuclease clips out UV- induced dimers, DNA polymerase III fills in the gap, and DNA ligase rejoins the phosphodiester backbone. 3. uses the corresponding region on the undamaged parental strand of the same polarity. 4. is a process in E. coli that induces error-prone DNA replication in an effort to fill gaps by inserting random nucleotides.

Answer 1

1. photoactivation is dependent on a photon activating enzyme which that cleaves thymine dimer

2.excision repair is the process by which an endonuclease clips out UV-induce dimers, DNA polymerase III fills in the gap, and DNA ligase rejoins the phosphodiester backbone

3.Recombinational Repair uses the corresponding regions on the undamaged parental strand of the same polarity

4. SOS repair is a process in E. coli that induces error-prone DNA replication in an effort to fill gaps by inserting random nucleotides