genetics 3

Question 1

what are the advantages of semi conservative DNA replication

Answer 1

• proof reading
• repair

Question 2

how is DNA replication in eukaryotes initiated

Answer 2

1) origin recognin complex (ORC) binds to replication origin
2) heliclase loading proteins recruited - Cdc6 and Cdt1
3) Mcm hexameric helical loaded to form prereplicative complex
4) cyclin- dependent kinase phosphorylates replication proteins and pre replicative complex disassembles
5) helicases unwinds DNA and DNA polymerase is recruited
6) DNA replication occurs

Question 3

what are the steps in prokaryotic DNA replication

Answer 3

1) initiator protein binds to DNA A
2) helicase binds
3) loading of helicase onto DNA
4) DNA unwinds and melts causing DNA primate to be recruited
5) DNA primer synthesis
6) DNA polymerase is recruited

Question 4

what is DNA primases role

Answer 4

• both leading and lagging strand
• adds RNA nucleotides
• allows DNA synthesis via DNA polymerase

Question 5

what is the DNA extension

Answer 5

• primed with RNA
• added to 3’ - OH

Question 6

what are Okazaki fragments joined by in a replication fork

Answer 6

• DNA ligase