Handout DNA and DNA Replication

DNA & DNA Replication Webquest Name:__________________________________________ Part 1: Interactive DNA Discovery 1. In which organelle is most DNA found? nucleus 2. How many chromosomes do you inherit from your father? 23 How many from your mother? 23 3. If you are male, what combination of chromosomes do you have? xy If female? xx 4. What does DNA contain instructions for? instructions for making proteins and RNAs 5. What is the role of proteins? Carrying out tasks necessary to maintain the cell (like transporting oxygen, etc.) 6. What are the sections of DNA that contain instructions for making proteins called? A gene ? 7. Does all of an organism’s DNA code for proteins? no 8. What does T pair with? A What does G pair with? C 9. If a DNA sequence is A-T-G-A-C, write the sequence of base pairs that would pair with it. T A C T G 10. What percent of humans’ DNA sequences are identical? 99.5 % 11. Can traits be determined by more than one gene? yes 12. What factors influence your traits? Lifestyle, Environment, and genetics Part 2: DNA Structure and Function Video 13. What does DNA stand for? Deoxyribonucleic acid 14. What does the information contained in DNA determine? Inherited characteristics 15. What does DNA code for? Making proteins 16. What are the monomers of DNA called? Nucleotides 17. What are the four nitrogen bases contained in DNA? a. Thymine b. adenine c. cytosine d. guanine 18. What phrase is used to describe the structure of DNA? Spiral or double helix 19. What is the backbone of DNA composed of? Alternating sugar and phosphate molecules 20. Which base pairs with adenine? Thymine Which base pairs with cytosine? guanine Nucleotide 21. Label the phosphate and deoxyribose sugar. Then write the first initial of the complementary base pairs. Write the full name of each base below its picture. C T G A G A C T Cytosine Thymine Adenine Phosphate Guanine Deoxyribose sugar Helpful Hint! Remember that Apples (A) go in a Tree (T) and Cars (C) go in a Garage (G). Part 3: DNA Replication Base Pairing Practice Game Click Pair and read the diagram. 22. What does DNA have to do before a cell divides? Make 2 copies of itself 23. Summarize the three steps of DNA replication. 1. An enzyme unwinds DNA and splits it apart into 2 separate strands 2. Each strand attracts complementary base to make an identical copy of original base pairs 3. Enzymes bind them to strands which then wind into 2 identical double helix DNA molecules 24. Click Play to play the game. Play it a few times until you get the hang of it. Then write your best score, speed, and the number of errors in the spaces below. a) Score: wont work for me, wont say score b) Speed:______________ c) Errors:______________ Part 4: DNA Replication Article 25. In which phase of the cell cycle does DNA replicate? S phase of interphase 26. Explain why DNA replication is a semi-conservative process. DNA replication results in 2 double helices, one strand of each helix being an old one, and one being a new one. 27. What is the role of DNA helicase? To break the hydrogen bonds holding the 2 strands together and to form a replication fork 28. Which enzyme reads and builds a complementary strand of DNA? DNA polymerase 29. What is the lagging strand synthesized by? The enzymes primase and liga 30. Which enzyme attaches the Ozaki fragments? DNA ligase Part 5: DNA Replication Video 31. Why does DNA have to replicate? So the daughter cell gets a copy 32. What do enzymes have the ability to do? To speed up reactions and build up/break down the items they act upon Fill in the table below with information from the video. Enzyme 33. Helicase Enzyme Nickname Unzipping enzyme Functions Breaks through hydrogen bonds that hold the bases together 34. DNA Polymerase The builder Replicate DNA molecules to build new strands of DNA 35. Primase The initializer Makes primer so DNA polymerase knows where to go 36. Ligase The gluer Helps glue DNA fragments togehter 37. What is the name of the part of DNA where DNA replication starts? The origin 38. What binds to the DNA strands to keep them separated? SSB proteins 39. What is the role of topoisomerase? To prevent the DNA from supercoiling 40. In which direction does the DNA Polymerase build a new strand? In the 5’ to 3’ direction 41. Why is the new strand named the lagging strand? Because it can only build in the 5’ to 3’ direction and has to keep racing up to where the unwinding is happening 42. What could happen is DNA Polymerase matches the wrong DNA bases? You could have an incorrectly coded gene which could result in an incorrect or no protein Part 6: DNA Replication Fork Labeling Activity 43. Write your final best score on the line to the right. 89 Your teacher may require that you submit a screenshot to prove your score. 44. Identify the name of each structure on 1. Lagging strand 2. Leading strand 3. DNA polymerase (pola) 4. DNA ligase 5. RNA primer 6. DNA primase 7. Okazaki fragment 8. DNA polymerase (polo) DNA Replication Fork 9. helicase 10. single strand binding proteins 11. topoisomerase