DNA Replication Simulations
Part 1: The DNA Ladder
Directions: Go to the DNA Ladder simulation. Click “Start interactive.” Use the
arrows on the left hand side to navigate through the simulation. Use the simulation
to answer the questions below.
1. Which type of chemical bonds hold together nucleotides in a single chain of
DNA?
covalent
2. Which type of chemical bonds connect the two strands of DNA?
hydrogen
3. Which type of chemical bond is broken during DNA replication?
hydrogen
4. Why are the nitrogenous bases on the interior of the two DNA strands?
Nitrogenous bases are hydrophobic
5. Why is DNA a common genetic language for all living organisms?
Complementary base pairing
Part 2: DNA Replication - 3D animation
Directions: Watch DNA replication animation. Use the animation to answer the
questions below.
6. Describe the complementary base pairing of the two DNA strands.
7. Describe the orientation of the two DNA strands relative to one another.
8. Describe the function of helicase.
9. Describe the function of DNA polymerase.
10. What are okazaki fragments?
Part 3: The Role of DNA Ligase in DNA Replication
Directions: Go to the DNA ligase simulation Click “Start interactive.” Use the arrows
on the left hand side to navigate through the simulation. Use the simulation to
answer the questions below.
11. Which direction does DNA polymerase “read”?
12. Where does DNA polymerase add new nucleotides?
13. What is the difference between the leading strand and the lagging strand?
14. Describe the function of ligase.