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.