Which of the following is not true of Griffith’s transformation experiment: 1. Rough bacteria were pathogenic 2. Dead smooth bacteria were used to transform living rough bacteria 3. Smooth bacteria have a capsule 4. Heat killed smooth bacteria were not pathogenic 53% 27% 13% 7% 1 2 3 4 This technique was used by Franklin and Wilkins to obtain much of the physical information about DNA structure: 1. Centrifugation 2. X-ray diffraction 3. Use of heavy isotopes 4. transformation 50% 33% 13% 4% 1 2 3 4 Mismatch repair is: 1. Due to UV radiation 2. Necessitated by the formation of T-T dimers 3. Necessitated by the occurrence of chromosomal duplication 4. Carried out by DNA polymerase 57% 19% 14% 10% 1 2 3 4 Experiments by these individuals were strongly supportive of DNA being the genetic material: 1. 2. 3. 4. 5. Griffith Messelson and Stahl Hershey and Chase Gorter and Grendle Franklin and Wilkins 50% 25% 17% 8% 0% 1 2 3 4 5 According to the “Central Dogma” 1. Mutation does not occur 2. Mistakes in replication are corrected 3. DNA is translated into protein 4. DNA is transcribed into RNA 61% 22% 13% 4% 1 2 3 4 Which of the following statements about DNA is false? 1. Adenine is complementary with guanine 2. DNA is antiparallel 3. A nucleotide has a sugar, phosphate, and one of four bases 4. It contains two polynucleotide strands 71% 5% 1 2 10% 3 14% 4 If the two DNA strands separate and each parent strand serves as a template for a new strand, DNA replication is: 1. 2. 3. 4. Conservative Dispersive Semiconservative None of the above 70% 26% 4% 1 2 0% 3 4 This DNA replication enzyme is used a single time in replicating the leading strand and multiple times when replicating the lagging strand 1. 2. 3. 4. DNA ligase DNA helicase RNA polymerase RNA primase 30% 30% 25% 15% 1 2 3 4 Which of the following investigators was/were responsible for the following discovery? Phage with labeled proteins or DNA was allowed to infect bacteria. It was shown that the DNA, but not the protein, entered the bacterial cells, and was therefore concluded to be the genetic material. A) Frederick Griffith B) Alfred Hershey and Martha Chase C) Oswald Avery, Maclyn McCarty, and Colin MacLeod D) Erwin Chargaff E) Matthew Meselson and Franklin Stahl 44% 22% 17% 11% 6% 1 2 3 4 5 Which of the following covalently connects segments of DNA? A) helicase B) DNA polymerase C) ligase D) toposiomerase E) primase 41% 23% 14% 14% 9% 1 2 3 4 5 Which of the following is not a characteristic of the genetic code? A. It’s a triplet code B. It’s a universal code C. It’s a redundant code D. It’s an overlapping code 38% 31% 19% 12% 1 2 3 4 In order to transcribe a eukaryotic gene into an m-rna, all of the following are required except: 1. 2. 3. 4. 5. a promotor a start codon Transcription factors RNA polymerase A TATA box 63% 19% 13% 6% 0% 1 2 3 4 5 If a mutation changes a codon that specifies an amino acid into a stop codon, that mutation is called 1. A missense mutation 2. A frameshift mutation 3. A nonsense mutation 4. An induced mutation 65% 15% 15% 5% 1 2 3 4 Post transcriptional modification of m-rna includes: 1. Adding a 3’Poly A tail 2. Adding a 5’ cap 3. Removing introns 4. 1 and 2 5. All of the above 65% 15% 15% 5% 0% 1 2 3 4 5 Introns 1. Are junk DNA with no known function 2. Are found in all types of rna 3. Allow one gene to produce several different polypeptide chains by alternative splicing 4. Are noncoding regions of a gene 5. 3 and 4 are correct 20% 1 20% 20% 2 3 20% 4 20% 5 Wobble is a concept associated with this molecule 1. 2. 3. 4. 5. DNA T-rna R-rna M-rna Sn-rna 45% 32% 14% 9% 0% 1 2 3 4 5 Aminoacyl t-rna synthetases are involved in joining these two types of molecules together: 1. RNA polymerase and transcription factors 2. T-rna and amino acids 3. T-rna and ribosomes 4. T-rna and m-rna 77% 15% 8% 0% 1 2 3 4 From the following list, which is the first event in translation in eukaryotes? A) elongation of the polypeptide B) base pairing of activated methioninetRNA to AUG of the messenger RNA C) the larger ribosomal subunit binds to smaller ribosomal subunits D) covalent bonding between the first two amino acids E) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA 20% 1 20% 20% 2 3 20% 4 20% 5 As a ribosome translocates along an mRNA molecule by one codon, which of the following occurs? A) The tRNA that was in the A site moves into the P site. B) The tRNA that was in the P site moves into the A site. C) The tRNA that was in the A site moves to the E site and is released. D) The tRNA that was in the A site departs from the ribosome via a tunnel. E) The polypeptide enters the E site. 68% 21% 5% 5% 0% 1 2 3 4 5 Which of the following DNA mutations is the most likely to be damaging to the protein it specifies? A) a base-pair deletion B) a codon substitution C) a substitution in the last base of a codon D) a codon deletion 38% 31% 23% E) a point mutation 8% 0% 1 2 3 4 5 A mutation that involves substitution of one nucleotide for another in a gene is called: 1. A frameshift mutation 2. A deletion mutation 3. A point mutation 4. A silent mutation 5. A nonsense mutation 67% 19% 14% 0% 1 2 0% 3 4 5 The Ames test is used to: 1. See if cells are transcribing genes 2. Test for the presence of Okasaki fragments 3. Determine if a substance is a mutagen and, thus, a possible carcinogen 4. Check lab animals for tumors 5. Determine if introns have been removed from m-rna 75% 20% 5% 1 2 3 0% 0% 4 5 Each of the following options is a modification of the sentence THECATATETHERAT. Which of the following is analogous to a frameshift mutation? A) THERATATETHECAT B) THETACATETHERAT C) THECATARETHERAT D) THECATATTHERAT E) CATATETHERAT 60% 20% 10% 10% 0% 1 2 3 4 5 Which of the following help(s) to stabilize mRNA by inhibiting its degradation? A) TATA box B) spliceosomes C) 5' cap and poly (A) tail D) introns E) RNA polymerase 42% 21% 17% 13% 8% 1 2 3 4 5 A mutant bacterial cell has a defective aminoacyl synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of a phenylalanine. The consequence of this for the cell will be that A) none of the proteins in the cell will contain phenylalanine. B) proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU. C) the cell will compensate for the defect by attaching phenylalanine to tRNAs with lysine-specifying anticodons. D) the ribosome will skip a codon every time a UUU is encountered. E) None of the above will occur; the cell will recognize the error and destroy the tRNA. 70% 20% 10% 0% 1 0% 2 3 4 5 For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogens. Thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates. Why won't this experiment work? A) There is no radioactive isotope of nitrogen. B) Radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long. C) Avery et al. have already concluded that this experiment showed inconclusive results. D) Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive. E) Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins. 25% 25% 25% 25% 0% 1 2 3 4 5 At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G C T G C A A T C C 5' An RNA primer is formed starting at the underlined T (T) of the template. Which of the following represents the primer sequence? A) 5' G C C T A G G 3' B) 3' G C C T A G G 5' C) 5' A C G T T A G G 3' D) 5' A C G U U A G G 3' E) 5' G C C U A G G 3' 40% 20% 20% 20% 0% 1 2 3 4 5 In which of the following actions does RNA primase differ from DNA polymerase? A) RNA polymerase uses RNA as a template, and DNA polymerase uses a DNA template. B) RNA polymerase binds to single-stranded DNA, and DNA polymerase binds to doublestranded DNA. C) RNA polymerase is much more accurate than DNA polymerase. D) RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis. E) RNA polymerase does not need to separate the two strands of DNA in order to synthesize an RNA copy, whereas DNA polymerase must unwind the double helix before it can replicate the DNA. 45% 27% 18% 9% 0% 1 2 3 4 5 What are the coding segments of a stretch of eukaryotic DNA called? A) introns B) exons C) codons D) replicons E) transposons 75% 20% 5% 1 2 3 0% 0% 4 5