Chapter 13 The Molecular Basis of Inceritance

Biology-Chapter 13 Focus Questions 13.1 Hershey and Chase devised an experiment using radioactive isotopes to determine whether it was a phage's DNA or protein that entered the bacteria and served as the genetic material of the T2 phage. A. How did they label phage protein? B. How did they label phage DNA? 13.2 Review the structure of DNA by labeling the following diagrams: GC b. 1 m L 13.3 Using different colors for heavy (parental) and light (new) strands of DNA, sketch the DNA molecules formed in two replication cycles after E. coli were moved from the medium containing 'N to medium containing "N. Show the resulting density bands in the centrifuge tubes. DNA molecules Density bands Parental DNA (grown on N medinum) First gearration (grown on light 14N medium) Second generation (grown on light N medium) 13.4 Look back to Focus Question 13.2 and label the 5' and 3' ends of the left strand of the DNA molecule. 13.5 In this diagram of bacterial DNA replication, label the following terms: leading and lagging strands, Okazaki fragment, DAN pol III, DNA pol I, DNA ligase, helicase, single-strand binding proteins, primase, DNA primer, and 5' and 3'ends of the parental DNA. 0000000000 13.6 List the multiple levels of packing in a metaphase chromosome in order of increasing complexity. 13.7 Which of the following DNA sequences would most likely function as a restriction site for a restriction enzyme? Why? 13.8 The following diagram depicts an overview of gene cloning. Identify components a-g. Briefly describe what is happening in the 3 numbered steps of the process. For what 2 purposes might the bacteria produced in step 3 be used? Banerium Cell corvaining gene of inverest 13.9. a. Why is PCR often used prior to cloning a gene in cells? b. Why even bother cloning genes in cells, given that PCR produces so many copies so fast? Name: Chapter 13 Active Reading Guide The Molecular Basis of Inheritance Section 1 1. Wher are the two chemical components of chromosomes? 2. Why did researchers originally think that protein was the genetic material? 3. Distinguish between the virulent and nonvirulent strains of Streptococcus pneumoniae studied by Frederick Griffith What was the purpose of Griffith's studies? 5 Summarize the experiment in which Griffith became aware that hereditary information could be transmitted between two organisms in an unusual manner 6. Define transformation 7. What did Oswald Avery determine to be the transforming factor? Explain his experimental approach 8. Sketch a 12 bacteriophage and label its head, tail sheath, tail ficer, and DNA 9. How does a bacteriophage destroy a bacterial cel? Look ahead to Chapter 17, Figure 17.4, to explain this 10. How did Horshey and Chase "label viral DNA and viral protein so that they could be distinguished? Explain why they chose each radioactive tag in light of the chemical composition of DNA and protein 11. Describe the means by which Harshey and Chase established that only the DNA of a phage enters an E col cell. What conclusions did these scientists draw based on these cbservations? 12. What are Chargal's rules? How did he arrive at there? 13. List the three components of a nucleotide 14. Who are the two men who built the first molecular model of DNA and shared the 1962 Nobel Prize for discovery of its structure? 2 15. What was the role of Rosalind Franklin in the discovery of the double holix? 16 Distinguish between the structure of pyrimidines and purines. Explain why adenine bonds only to thymine. 17 How did Watson and Crick's modet explain the basis for Chargutt's rules? 18. Given that the DNA of a certain fly species consists of 27.3% adonine and 22.5% guanine, use Chargaff's rules to deduce the percentages of thymine and cytosino 19. Name the five nitrogenous bases, and put a checkmark in the correct column for coch base. Also indicate if the base is found in DNA, RNA, or both Nitrogenous Base Purine Pyrimidine DNA, RNA, or Both 20. What DNA base is complementary to adenine? What DNA bese is complementary to guanine? 21. Describe the structure of DNA relative to each of the following: a distance across molecule b. distance between nucleotides distance between tums d components of the backbone o components of the "rungs" 22. Explain what is meant by 5 and 3' ends of the nudecide 23. What do we mean when we say the two strands of DNA are antiparalle? Section 2 24. What is the semiconservative mode of repication? 25. Who performed the experiments that elucidated the correct mechanism of DNA replication? 26. How did Meselson and Stahl create "heavy" DNA for their experiments? 27. Use Figure 13.11 to explain how Meselson and Stahl confirmed the semiconservative mechanism of DNA replication 25. Define the origins of replication.