Question

DNA Replication

1. Define DNA replication.

2. What is the role of base pairing in DNA replication? Would this process of replication be possible without base pairing?

3. Describe the process of semi-conservative DNA replication.

4. Describe the experiment that led to the discovery that DNA was replicated through a semi-conservative process.

5. Define replication origins.

6. Why is the specific sequence of the replication origin relevant to DNA replication?

7. Describe the process of DNA replication, including the enzymes involved, the direction in which DNA is read and new DNA is added, and the difference between the leading and lagging strands.

8. Why are new nucleotides added to DNA in a 5’ to 3’ direction? Would DNA replication work if new nucleotides were added in a 3’ to 5’ direction? Why or why not?

9. What is the role of RNA primase in DNA replication? How would DNA replication proceed if RNA primase was malformed?

10. What advantage do prokaryotic circular chromosomes offer over linear eukaryotic chromosomes?

11. How do eukaryotic organisms replicate the ends of their chromosomes without losing important nucleotides?

12. Why does DNA polymerase proofread the DNA in a 3’ to 5’ direction?

How would DNA replication and mutation differ if DNA were single-stranded?

Answer 1

DNA replication is the synthesis of daughter DNA strands using parent DNA strands as a template.

New daughter strands are complementary to the parent strand. They are extended via base pairing. If the base pairing is absent, DNA synthesis would not be complementary.

DNA replication is discontinuous, bidirectional and semi-conservative.

Semi-conservative replication refers to the fact that daughter DNA duplexes contain one parental and one newly synthesized DNA strands.

Replication origin is the site where DNA replication begins.