Chapter 10 DNA Structure and Analysis1) The basic structure of a nucleotide includes ________.A) amino acidsB) tryptophan and leucineC) base, sugar, and phosphateD) mRNA, rRNA, and tRNAE) phosphorus and sulfurAnswer: CSection: 10.62) The classic Hershey and Chase (1952) experiment that offered evidence in support of DNA being the genetic material in bacteriophages made use of which of the following labeled component(s)?A) phosphorus and sulfurB) nitrogen and oxygenC) tritiumD) hydrogenE) None of the answers listed is correct.Answer: ASection: 10.33) Reverse transcriptase is an enzyme found in association with retroviral activity. It has the property of ________. A) synthesis of DNA from an RNA templateB) synthesis of RNA from a DNA templateC) requiring no templateD) translationE) most lysozymesAnswer: ASection: 10.54) What are the two major components of the Tobacco Mosaic Virus?A) RNA and DNAB) DNA and proteinC) RNA and proteinD) lipids and nucleic acidsE) carbohydrates and nucleic acidsAnswer: CSection: 10.51Copyright © 2012 Pearson Education, Inc.5) Considering the structure of double-stranded DNA, which kind(s) of bonds hold one complementary strand to the other? A) ionicB) covalentC) van der WaalsD) hydrogenE) hydrophobic and hydrophilicAnswer: DSection: 10.76) Regarding the structure of DNA, the covalently arranged combination of a deoxyribose and a nitrogenous base would be called a(n) ________.A) nucleotideB) ribonucleotideC) monophosphate nucleosideD) oligonucleotideE) nucleosideAnswer: ESection: 10.67) In the classic experiment conducted by Hershey and Chase, why was the pellet radioactive in the centrifuge tube that contained bacteria with viruses?A) The bacteria were in the pellet, and they had incorporated radioactive proteins into theircell membranes.B) The radioactive viruses (coats plus DNA) were in the pellet.C) The bacteria were in the pellet, and many contained the radioactive viral DNA.D) The radioactive protein coats of the viruses were in the pellet.E) The radioactive viruses were in the pellet, and the bacteria were in the supernatant.Answer: CSection: 10.38) If 15% of the nitrogenous bases in a sample of DNA from a particular organism is thymine, what percentage should be cytosine?A) 15%B) 30%C) 35%D) 40%E) 70%Answer: CSection: 10.6, 10.72Copyright © 2012 Pearson Education, Inc.9) In an analysis of the nucleotide composition of double-stranded DNA to see which bases are equivalent in concentration, which of the following would be true?A) A = CB) A = G and C = TC) A + C = G + TD) A + T = G + CE) A = G and C = T and A + C = G + T are both true.Answer: CSection: 10.6, 10.710) Is the accompanying figure DNA or RNA? ________ Is the arrow closest to the 5' or 3' end? ________ Spleen diesterase is an enzyme that breaks the covalent bond that connects the phosphate to the 5' carbon. Assume that the dinucleotide is digested with spleen diesterase. To which base and to which carbon on the sugar is the phosphate now attached, A or T?A) DNA; 3' end; T, 5'B) RNA; 3' end; A, 3'C) DNA; 5' end; A, 5'D) DNA; 3' end; A, 3'E) RNA; 3' end; T, 3'Answer: DSection: 10.511) Which of the following clusters of terms accurately describes DNA as it is generally viewed to exist in prokaryotes and eukaryotes?A) double-stranded, parallel, (A + T)/(C + G) = variable, (A + G)/(C + T) = 1.0B) double-stranded, antiparallel, (A + T)/(C + G) = variable, (A + G)/(C+ T) = 1.0C) single-stranded, antiparallel, (A + T)/(C + G) = 1.0, (A + G)/(C + T) = 1.0D) double-stranded, parallel, (A + T)/(C + G) = 1.0, (A + G)/(C + T) = 1.0E) double-stranded, antiparallel, (A + T)/(C + G) = variable, (A + G)/(C + T) = variableAnswer: BSection: 10.6, 10.712) Briefly define transformation and describe the relationship between the phenomenon of transformation and the discovery that DNA is the genetic material in bacteria. Answer: Transformation is the process whereby one organism is genetically altered by exposure to DNA from another organism. Since DNA can carry heritable "traits" from one organism to another, it must be the genetic material.Section: 10.33Copyright © 2012 Pearson Education, Inc.13) Present an overview of two classical experiments that demonstrated that DNA is the genetic material. Can RNA be the genetic material? Explain.Answer: (1) Transformation in bacteria (Griffith through Avery et al.); see appropriate figures in the Klug/Cummings text. (2) The Hershey and Chase experiment in bacteriophage; see appropriate figures in the Klug/Cummings text. Yes, RNA can be the genetic material as described for the Tobacco Mosaic Virus (TMV), retroviruses, and many others.Section: 10.3, 10.514) Describe four major functions of DNA in a cell. Answer: replication = duplication of genetic material; expression = production of a phenotype; storage = stable maintenance and passage of information; variation = capable of alterationSection: 10.115) Consider the structure of double-stranded DNA. When DNA is placed into distilled water, it denatures; however, by adding NaCl, the DNA renatures. Why?Answer: The negatively charged phosphates repel each other on the two sides of the helix. In distilled water, these charges are not neutralized (by positively charged ions), and the hydrogen bonds, which hold the double helix together, are broken. In the presence of positive ions, such charges are neutralized.Section: 10.1016) If the GC content of a DNA molecule is 60%, what are the molar percentages of the four bases (G, C, T, A)?Answer: G = 30%, C = 30%, T = 20%, A = 20%Section: 10.6, 10.717) Explain how and why the following circumstances influence characteristics of temperature-induced DNA melting. Percentage of GC base pairsUrea (forms hydrogen bonds with bases)Sodium chloride (neutralizes negatively charged phosphates)Answer: GC pairs are composed of three hydrogen bonds and require more energy (heat) to separate than do AT pairs. Urea competes for hydrogen bonds; thus, the bases pair with the urea rather than with each other. This weakens the complementary associations that are required to hold the DNA helix together; thus, less heat is required for melting. The sodium of sodium chloride associates with and neutralizes the strong negative charges on the phosphates. The phosphates do not repel each other with the sodium ion present; thus, the double-stranded structure requires more energy to melt.Section: 10.1018) Assume that the molar percentage of thymine in a double-stranded