DNA replication

Question 1

Models of DNA replication

Answer 1

• conservative
• semi-conservative
• dispersive

Question 2

DNA replication in prokaryotes

Answer 2

• Circular DNA of relatively small size
• Single origin of replication
• Can replicate in less than 40 minutes = 1000 nucleotides/second !
• Series of enzymes involved, forming the replisome and leading to bidirectional DNA replication

Question 3

DNA replication in eukaryotes

Answer 3

• Linear, large genomes
• Replication starts at multiple locations
• No conserve initiating points of replication
• Chromatin state dictates replication points

Question 4

Name 3 steps in replication of DNA

Answer 4

• initiation
• elongation
• termination

Question 5

Replication fork

Answer 5

• helicase (initiator protein)
• origin licensing
• origin firing

Question 6

Origin licensing

Answer 6

Refers to a conserved protein complex required to load the helicases on the DNA at a potential site of
replication.

Question 7

Origin firing

Answer 7

Not all loaded helicases will become activated in order to form replication forks.

Question 8

Okazaki fragments

Answer 8

Synthesis of lagging strand happen in fragments