31. During DNA repair in both prokaryotes and eukaryotes, which of the following enzymes forms a phosphodiester bond between the undamaged DNA sequence, and the newly synthesized DNA section, after the correct nucleotides have been linked together to replace the damaged nucleotides? RNA polymerase DNA helicase an exonuclease DNA ligase topoisomerase

3a) In eukaryotic cells that lack telomerase, the telomeres at the ends of the chromosomes gradually get shorter with each round of DNA replication. Describe or explain why the "normal" DNA replication machinery, excluding telomerase, can't completely and accurately replicate all the DNA at the ends of linear chromosomes. Please note that the question does NOT ask you to describe what telomerase does - it asks you to explain why cells without telomerase have this problem.

Optimal DNA replication requires the coordinated effort of all the following EXCEPT:   gyrase   single strand binding proteins   DNA polymerase II   Primase

besides DNA pol I and DNA pol III What are the roles of the other enzymes involved in replication and why they're necessary ?

Semi-discontinuous replication means that:     DNA synthesis only occurs in the same direction as the replication fork.     the double helix unwinds and each strand serves as a template for a new DNA molecule.     there are Okazaki fragments associated with the leading strand.     DNA synthesis occurs in both a 5’ to 3’ and a 3’ to 5’ direction.     there is both a leading and a lagging strand associated with each replication fork.

Elaborate repair mechanisms that prevent permanent mutations in DNA are associated with replication, yet no similar repair process is associated with transcription. Can you think of a reason for this difference between replication and transcription? (Hint: Think about the relative effects of a permanent mutation in a DNA molecule and one in an RNA molecule.)

In each cell if DNA polymerase I is non-functional, how would it affect the leading strand

Replication in eukaryotes begins at the OriC sequence. This particular sequence is characterized by (select the correct statements): A-T rich and therefore energetically more favourable to localy unwind DNA. Contains the DnaA boxes. Recruits histone acetyltransferases. Is locally unwound by DnaA, HU and IHF proteins. QUESTION 16 The Single Strand-binding proteins (SSBS) in prokaryotes and the Replication Protein A (RPA) in eukaryotes are functionally equivalent. Their role in the DNA replication process is to (select the correct statement): Stabilize the single stranded DNA structure after unwinding by the DNA helicase. Recruit the general transcription factors to the promoter. Relieve the torsional stress ahead of the replication fork. Induce double strand breaks. O O O O O O O

Which of the following DNA repair processes is known to be "error-prone" (i.e. resulting in incorporation of incorrect nucleotides as part of the repair process)? Mark all the answers that are correct. Base Excision Repair (BER) non-homologous end-joining of double-stranded DNA breaks. O Nucleotide Excision Repair (NER) post-replication repair SO-response

Which of the following is correct about the function of DNA Ligase? DNA ligase is used on the leading strand and it joins any disconnected strand together O DNA ligase is used on the lagging strand which helps in joining fragments of the strand together O DNA ligase is used on the lagging strand and it aids in correcting mistakes on this specific strand O DNA ligase is used to maintain the replication fork structure