Campbell Biology Chapter 17 Gene Expression PDF

Campbell Biology, 12e (Urry) Chapter 17 Gene Expression: From Gene to Protein 17.1 Multiple Choice Questions 1) Which of the following statements correctly describes Archibald Garrod's hypothesis for how "inborn errors of metabolism" such as alkaptonuria occur? A) Metabolic enzymes require vitamin...

Campbell Biology, 12e (Urry) Chapter 17 Gene Expression: From Gene to Protein 17.1 Multiple Choice Questions 1) Which of the following statements correctly describes Archibald Garrod's hypothesis for how "inborn errors of metabolism" such as alkaptonuria occur? A) Metabolic enzymes require vitamin cofactors, and affected individuals have significant nutritional deficiencies. B) Enzymes are made of DNA, and affected individuals lack DNA polymerase. C) Certain metabolic reactions are carried out by ribozymes, and affected individuals lack key splicing factors. D) Genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes. Answer: D Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-PS 2) A particular triplet of bases in the template strand of DNA is 5′-AGT-3′. What would be the corresponding codon for the mRNA that is transcribed? A) 3′-UCA-5′ B) 3′-ACU-5′ C) 5′-AGT-3′ D) 5′-UCA-3′ Answer: A Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.1, Global LO: G2, V&C LO: VC-I 3) The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true? A) A gene from an organism can theoretically be expressed by any other organism. B) DNA was the first genetic material. C) The same codons in different organisms translate into different amino acids. D) Different organisms have different types of amino acids. Answer: A Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 5-6: Evaluating/Creating Learning Outcome: 17.1, Global LO: G2, V&C LO: VC-I 1 Copyright © 2021 Pearson Education, Inc. 4) Use the figure to answer the question. The figure shows a simple metabolic pathway. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway? A) 2 B) 3 C) 5 D) It cannot be determined from the information provided. Answer: A Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.1, Global LO: G2, V&C LO: VC-EM 5) Use the figure to answer the question. Refer to the metabolic pathway illustrated. If I, II, III, and IV are all required for growth, a bacterial strain that does not make enzyme X would be able to grow on medium supplemented with which of the following nutrient(s)? A) nutrient A only B) nutrient B only C) nutrients A and B only D) nutrients B, C, and D only Answer: C Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.1, Global LO: G2, V&C LO: VC-EM 2 Copyright © 2021 Pearson Education, Inc. 6) Use the figure to answer the question. Refer to the metabolic pathway illustrated. If I, II, III and IV are all required for growth, a bacterial strain that does not make enzyme Y would be able to grow on medium supplemented with which of the following compounds? A) nutrient A only B) nutrient C only C) nutrients A and C only D) nutrients B and D only Answer: C Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.1, Global LO: G2, V&C LO: VC-EM 3 Copyright © 2021 Pearson Education, Inc. 7) The following question refers to this table of codons. What amino acid sequence will be generated based on the following mRNA codon sequence? 5′-AUG-UCU-UCG-UUA-UCC-UUG-3′ A) Met-Arg-Glu-Arg-Glu-Arg B) Met-Glu-Arg-Arg-Glu-Leu C) Met-Ser-Leu-Ser-Leu-Ser D) Met-Ser-Ser-Leu-Ser-Leu Answer: D Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.1, Global LO: G2, V&C LO: VC-I 4 Copyright © 2021 Pearson Education, Inc. 8) The following question refers to this table of codons. Refer to the figure. Which of the triplets below is a possible anticodon in a tRNA that transports proline to a ribosome? A) 5′-GGT-3′ B) 5′-CCG-3′ C) 3′-GGC-5′ D) 3′-CCC-5′ Answer: C Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.1, Global LO: G2, V&C LO: VC-I 5 Copyright © 2021 Pearson Education, Inc. 9) Which of the following statements best supports the one gene-one enzyme hypothesis? A) A mutation in a single gene can result in a defective protein. B) Alkaptonuria results when individuals lack multiple enzymes involved in the catalysis of homogentisic acid. C) Sickle-cell anemia results in normal hemoglobin. D) Multiple antibody genes can code for different related proteins, depending on the splicing that takes place post-transcriptionally. Answer: A Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.1, Global LO: G2, V&C LO: VC-I 10) Which of the following characteristics is directly related to the coding of a single amino acid during the process of translation? A) the base sequence at the tRNA 5′ end B) the amino acetyl tRNA synthase used C) the three-base sequence of mRNA D) the complementary binding of DNA with RNA Answer: C Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 11) Which of the following processes occurs as part of transcription? A) DNA is replicated B) RNA is synthesized C) proteins are synthesized D) mRNA attaches to ribosomes Answer: B Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 12) Which of the following molecular structures contains codons? A) a protein B) mRNA C) tRNA D) rRNA Answer: B Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 6 Copyright © 2021 Pearson Education, Inc. 13) Which of the following best describes the redundancy in the genetic code? A) A single codon can specify the addition of more than one amino acid. B) The genetic code is different for different domains of organisms. C) The genetic code is universal (the same for all organisms). D) More than one codon can specify the addition of the same amino acid. Answer: D Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 14) Once researchers identified DNA as the molecule responsible for transmitting heritable traits, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. Which of the following statements correctly describes the mechanism of information transfer that accomplishes this task in eukaryotes? A) DNA from a single gene is replicated and transferred to the cytoplasm, where it serves as a template for protein synthesis. B) Messenger RNA is transcribed from a single gene and transfers information to the cytoplasm, where protein synthesis takes place. C) RNA polymerase transfers information from the nucleus to tRNA synthase in the cytoplasm, where protein synthesis takes place. D) Transfer RNA takes information from DNA directly to a ribosome, where protein synthesis takes place. Answer: B Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 15) According to the central dogma, which of the following intermediate molecules correctly completes the flow chart describing the flow of information in a cell blank? DNA → ________ → Proteins A) enzymes B) rRNA C) mRNA D) tRNA Answer: C Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 7 Copyright © 2021 Pearson Education, Inc. 16) Which of the following molecules carries information from DNA and directs incorporation of amino acids at the ribosome? A) enzymes B) rRNA C) mRNA D) tRNA Answer: C Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 17) Which answer correctly compares prokaryotic and eukaryotic codons? A) Prokaryotic codons usually contain different bases than those of eukaryotes. B) Prokaryotic codons usually specify different amino acids than those of eukaryotes. C) Organism within a phylum share codons that are distinct from organisms in other phyla. D) Organisms utilize codons that are nearly universal among all organisms. Answer: D Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 18) Which of the following processes occurs in prokaryotes but not in eukaryotes? A) removing introns from pre-RNA B) simultaneous transcription and translation of the same mRNA C) translation in the absence of a ribosome D) translocation into the ER Answer: B Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1, Global LO: G1, V&C LO: VC-I 19) Which of the following statements best describes the termination of transcription in prokaryotes? A) RNA polymerase transcribes through the polyadenylation signal, causing proteins to associate with the transcript and cut it free from the polymerase. B) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript. C) Once transcription has initiated, RNA polymerase transcribes until it reaches the end of the chromosome and releases. D) RNA polymerase transcribes through a stop codon, causing the polymerase to stop advancing through the gene and release the mRNA. Answer: B Topic: Transcription is the DNA-directed synthesis of RNA: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.2, Global LO: G1, V&C LO: VC-I 8 Copyright © 2021 Pearson Education, Inc. 20) In eukaryotes, there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a protein? A) RNA polymerase I B) RNA polymerase II C) RNA polymerase III D) primase Answer: B Topic: Transcription is the DNA-directed synthesis of RNA: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.2, Global LO: G1, V&C LO: VC-I 21) Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase? A) anticodons B) ribosomes and tRNA C) transcription factors D) aminoacyl-tRNA synthetase Answer: C Topic: Transcription is the DNA-directed synthesis of RNA: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.2, Global LO: G1, V&C LO: VC-I 22) Which of the following statements best describes the significance of the TATA box in the promoters of eukaryotes? A) It is the recognition site for the binding of a specific transcription factor. B) It sets the reading frame of the mRNA during translation. C) It is the recognition site for ribosomal binding during translation. D) It is the recognition site for ribosomal binding during transcription. Answer: A Topic: Transcription is the DNA-directed synthesis of RNA: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.2, Global LO: G1, V&C LO: VC-I 23) Which of the following statements correctly describes a ribozyme? A) It is a catalyst that uses RNA as a substrate. B) It is an RNA with catalytic activity. C) It is an enzyme that catalyzes the association between the large and small ribosomal subunits. D) It is an enzyme that synthesizes RNA as part of the transcription process. Answer: B Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.3, Global LO: G1, V&C LO: VC-I 9 Copyright © 2021 Pearson Education, Inc. 24) RNA is single stranded, can hydrogen-bond with other nucleic acids, and has functional groups that can function in catalysis. These characteristics support that RNA could have which of the following cellular roles? A) tagging proteins for degradation by lysosomes B) targeting proteins for secretion C) forming scaffolds for ribosome attachment D) forming peptide bonds Answer: D Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 5-6: Evaluating/Creating Learning Outcome: 17.3, Global LO: G2, V&C LO: VC-I 25) Which of the following processes correctly describes alternative RNA splicing? A) It is a mechanism for increasing the rate of translation. B) It can allow the production of proteins of different sizes and functions from a single mRNA. C) It can allow the production of similar proteins from different RNAs. D) It increases the rate of transcription. Answer: B Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.3, Global LO: G1, V&C LO: VC-I 26) In the structure of many eukaryotic genes, individual exons parallel which of the following? A) the sequence of the intron that immediately precedes each exon B) the number of polypeptides making up the functional protein C) the various domains of the protein product D) the number of start sites for transcription Answer: C Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.3, Global LO: G1, V&C LO: VC-I 27) Which of the following is most likely to occur if a researcher removes the 5′ cap and poly-A tail of an mRNA and inserts the mRNA molecule into a eukaryotic cell? A) The mRNA will be quickly converted into a ribosomal subunit. B) The cell will add a new poly-A tail to the mRNA. C) The mRNA will attaches to a ribosome and be translated, but more slowly. D) The molecule will be degraded by enzymes. Answer: D Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 5-6: Evaluating/Creating Learning Outcome: 17.3, Global LO: G9, V&C LO: VC-PS 10 Copyright © 2021 Pearson Education, Inc. 28) Two mRNAs (mRNA X and mRNA Y) are synthesized with the same exon sequences but poly-A tails of very different lengths. mRNA X is 7,500 bases long. mRNA Y is 6,900 bases long. The mRNA's are added to separate in vitro translation mixtures containing radioactive methionine and the reactions are allowed to proceed for 30 minutes. When the mixtures are analyzed which of the following outcomes will most likely occur? A) The mRNA X mixture will contain radioactive proteins but the mRNA Y mixture will not. B) The radioactive proteins in the mRNA X mixture will be larger in size than those in the mRNA Y mixture. C) The mRNA X mixture will contain more radioactive proteins than the mRNA Y mixture. D) The radioactive proteins in the mRNA X mixture will begin with methionine while those in the mRNA Y mixture will not. Answer: C Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 5-6: Evaluating/Creating Learning Outcome: 17.3, Global LO: G9, V&C LO: VC-PS 29) Use this model of a eukaryotic primary transcript to answer the following question. E = exon and I = intron 5′-UTR E1 I1 E2 I2 E3 I3 E4 UTR-3′ If the primary transcript is processed and transported to the cytosol, which of the following molecules best represents the mRNA that will be produced? A) 5′-UTR I1 I2 I3 UTR-3′ B) 5′-E1 E2 E3 E4-3′ C) 5′-UTR E1 E2 E3 E4 UTR-3′ D) 5′-E1 I1 E2 I2 E3 I3 E4-3′ Answer: C Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.3, Global LO: G3, V&C LO: VC-I 30) Which of the following statements about RNA processing is correct? A) Exons are removed before mRNA leaves the nucleus. B) Ribozymes may function in RNA splicing. C) RNA splicing can be catalyzed by tRNA. D) A primary transcript is often much shorter than the final RNA molecule that leaves the nucleus. Answer: B Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.3, Global LO: G1, V&C LO: VC-I 11 Copyright © 2021 Pearson Education, Inc. 31) Which answer correctly compares the primary transcript in the nucleus of a eukaryotic cell with the functional mRNA? A) the primary transcript is the same size as the mRNA B) the primary transcript is larger than the mRNA C) the primary transcript is smaller than the mRNA D) both the primary transcript and mRNA contain introns Answer: B Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.3, Global LO: G2, V&C LO: VC-I 32) Which answer correctly compares the primary transcript in a prokaryotic cell with the functional mRNA? A) the primary transcript is larger than the mRNA B) the primary transcript is smaller than the mRNA C) the primary transcript and the mRNA both contain introns D) the primary transcript is the same size as the mRNA Answer: D Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.3, Global LO: G2, V&C LO: VC-I 33) Which of the following characteristics of gene expression is shared by eukaryotic and prokaryotic cells? A) Translation occurs before transcription. B) Transcription of an mRNA is temporally separated from its translation. C) Ribosomes attach to the plasma membrane when producing secreted proteins. D) Signal sequences are needed for the production of membrane proteins. Answer: D Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 5-6: Evaluating/Creating Learning Outcome: 17.3, Global LO: G2, V&C LO: VC-I 34) A particular triplet of bases in the coding sequence of DNA is 5'-AAA-3'. The anticodon on the tRNA that binds the mRNA codon is ________. A) 5′-TTT-3′ B) 5′-UUA-3′ C) 3′-UUU-5′ D) 3′-AAA-5′ Answer: D Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I 12 Copyright © 2021 Pearson Education, Inc. 35) Accuracy in translation of mRNA into the primary structure of a polypeptide depends on specificity in the ________. A) binding of ribosomes to the mRNA B) binding of the anticodon to small subunit of the ribosome C) attachment of amino acid's carboxyl group with the amine of the next amino acid. D) attachment of amino acids to tRNAs Answer: D Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-I 36) If a bacteria contained a mutant aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA which of the following would occur? 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. Answer: B Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I 37) Which of the following best explains the observation that in bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs? A) Some tRNAs have anticodons that recognize four or more different codons. B) The rules for base pairing between the third base of a codon and tRNA are flexible. C) Many codons are never used, so the tRNAs that recognize them are dispensable. D) The DNA codes 61 tRNAs, but some are destroyed after transcription. Answer: B Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-I 38) In eukaryotes which of the following is the first step in translation? A) base pairing of activated methionine-tRNA to AUG of the messenger RNA B) binding of the larger ribosomal subunit to smaller ribosomal subunits C) the ribosome reaches a stop codon D) the small subunit of the ribosome recognizes and attaches to the 5′ cap of mRNA Answer: D Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-I 13 Copyright © 2021 Pearson Education, Inc. 39) Which of the following statements correctly describes the function of a signal peptide? A) It directs an mRNA molecule into the lumen of the ER. B) It terminates translation of messenger RNA. C) It helps target a protein to the ER. D) It signals the initiation of transcription. Answer: C Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-SF 40) What is the function of the release factor during translation in eukaryotes? A) It binds to the stop codon in the A site in place of a tRNA. B) It releases the amino acid from its tRNA to allow the amino acid to form a peptide bond. C) It supplies a source of energy for termination of translation. D) It releases the ribosome from the ER to allow polypeptides into the cytosol. Answer: A Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-SF 41) Use the following information to answer the question. An mRNA molecule with the sequence 5′-CCG-ACG-3′is being translated at a ribosome. The following charged transfer RNA molecules (with their anticodons shown in the 3′ to 5′ direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. tRNA Anticodon Amino Acid GGC Proline CGU Alanine UGC Threonine CCG Glycine ACG Cysteine CGG Alanine Which of the following dipeptides will form from this mRNA? A) cysteine-alanine B) proline-threonine C) glycine-cysteine D) alanine-alanine Answer: B Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I 14 Copyright © 2021 Pearson Education, Inc. 42) An mRNA molecule with the sequence 5′-CCG-ACG-3′is being read by a ribosome. During translation which of the following tRNA anticodons will be the first to productively bind with this mRNA? A) 3′-GGC-5′ B) 5′-GGC-3′ C) 5′-UGC-3′ D) 3′-UGC-5′ Answer: A Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I 15 Copyright © 2021 Pearson Education, Inc. 43) Use the figure to answer the question. What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure? A) ionic bonding between phosphates B) hydrogen bonding between base pairs C) van der Waals interactions between hydrogen atoms D) peptide bonding between amino acids Answer: B Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-SF 16 Copyright © 2021 Pearson Education, Inc. 44) Use the figure to answer the question. Which codon on the mRNA strand codes for the amino acid carried by the aminoacyl-tRNA represented in the figure? A) 5′-UGG-3′ B) 3′-GUG-5′ C) 5′-GUA-3′ D) 5′-UUC-3′ Answer: D Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I 17 Copyright © 2021 Pearson Education, Inc. 45) Which of the following processes will occur at the exposed 3′ end of a tRNA molecule? A) An amino acid will bind covalently. B) The single stranded nucleotides (ACCA) will be removed to stabilize the tRNA. C) The small and large subunits of the ribosome will attach to the 3" end. D) The 5′ cap of the mRNA will bind covalently. Answer: A Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-SF 46) Which of the following properties is associated with a protein that will be secreted from a eukaryotic cell? A) It must be translated by a ribosome that remains free within the cytosol. B) Its signal sequence must target it to the ER. C) Its signal sequence must be cleaved off as the polypeptide enters the ER. D) Its signal sequence must target it to the plasma membrane. Answer: B Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-SF 47) Which of the following molecules directly participates in the process of translation? A) mRNA, tRNA, DNA, and rRNA B) mRNA, DNA, and rRNA C) mRNA, tRNA, and rRNA D) mRNA, tRNA, and DNA Answer: C Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-I 48) During the elongation phase of translation, which site in the ribosome represents the first location where a codon pairs with an anticodon? A) E site B) P site C) A site D) the large ribosomal subunit Answer: C Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-I 18 Copyright © 2021 Pearson Education, Inc. 49) Which of the following structures is needed for the translation initiation complex to form in eukaryotes? A) promoter B) exon C) 5′ cap D) 5′ AUG 3′ Answer: C Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I 50) Translation termination occurs when a ribosome interacts with which of the following structures? A) the end of the mRNA molecule. B) a stop codon C) the 5′ cap D) the poly-A tail Answer: B Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-I 51) Post-translational modifications of proteins may include which of the following processes? A) removal of introns B) addition of a 5′ cap C) synthesis of peptide bonds D) addition of carbohydrates to form a glycoprotein Answer: D Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.4, Global LO: G2, V&C LO: VC-I 52) Which of the following statements is true about protein synthesis in prokaryotes? A) Extensive RNA processing is required before transcripts can be translated. B) Translation can begin while transcription is still in progress. C) Protein targeting to cellular organelles requires recognition of signal sequences. D) Translation requires no initiation or elongation factors. Answer: B Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4, Global LO: G1, V&C LO: VC-I 19 Copyright © 2021 Pearson Education, Inc. 53) While characterizing an error-prone organism, researchers found that each of the following types of mutations occurred immediately downstream of the translation start site. Which type of mutation is likely to have the most serious effect on the function of the polypeptide product? A) a deletion of a codon B) a deletion of two nucleotides C) a substitution of the third nucleotide in an ACC codon D) a substitution of the first nucleotide of a GGG codon Answer: B Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 5-6: Evaluating/Creating Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-I 54) Which of the following statements describes the effect of a nonsense mutation on a gene? A) It changes only one amino acid in the encoded protein. B) It has no effect on the amino acid sequence of the encoded protein. C) It introduces a premature stop codon into the mRNA. D) It alters the reading frame of the mRNA. Answer: C Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.5, Global LO: G1, V&C LO: VC-I 55) Which of the following changes in an exon is most likely to result in a nonfunctional protein product? A) a base-pair deletion B) an addition of three nucleotides C) a substitution in the last base of a codon D) a codon deletion Answer: A Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-I 56) The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the result of this type of mutation? A) a base-pair substitution B) a frameshift mutation C) a polypeptide missing an amino acid D) a polypeptide missing its N-terminus Answer: C Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-I 20 Copyright © 2021 Pearson Education, Inc. 57) Which of the following statements is the most current description of a gene? A) a unit of heredity that causes formation of a phenotypic characteristic B) a DNA subunit that codes for a single complete protein C) a DNA sequence that is expressed to form a functional RNA or polypeptide product D) a discrete unit of hereditary information that consists of a sequence of amino acids Answer: C Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.5, Global LO: G1, V&C LO: VC-I 58) Which of the following describes the most likely effect that a single base substitution in the middle of gene's sequence will have on the protein the gene encodes? A) A single amino acid would change because pairing of mRNA and tRNA in the ribosome would change. B) The protein would be shorter because the correct tRNA would not be able to interact with the ribosome. C) All amino acids following the substitution would be affected because the reading frame would be altered. D) There would be no change because the genetic code is ambiguous. Answer: A Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-I 59) A section of DNA has the base sequence shown in #1. A mutation in this DNA strand results in the base sequence shown in #2. What type of mutation does this change represent? #1 5' - AGCGTTACCGT-3' #2 5'-AGGCGTTACCGT-3' A) a missense mutation B) a point mutation C) a silent mutation D) frameshift mutation Answer: D Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-I 21 Copyright © 2021 Pearson Education, Inc. 60) A single base substitution mutation is likely to have a less harmful effect when the base change results in which of the following? A) a stop codon B) a codon that specifies the same amino acid as the original codon C) an amino acid substitution that alters the tertiary structure of the protein D) an amino acid substitution at the active site of an enzyme Answer: B Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-I 61) Rank the following mutations with respect to their likelihood of affecting the structure of the polypeptide (from most likely to affect structure to least likely). 1. insertion mutation in the middle of an intron 2. deletion of 3 bases crossing an intron-exon border 3. substitution mutation at the third position of a codon 4. substitution mutation at the second position of a codon A) 1, 2, 4, 3 B) 2, 3, 4, 1 C) 3, 4, 2, 1 D) 4, 3, 2, 1 Answer: B Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 3-4: Applying/Analyzing; Levels 5-6: Evaluating/Creating Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-I 62) Which of the following characteristics allows the CRISPR Cas9 enzyme to be an effective way to generate mutations that block the function of a specific protein (knock out)? A) It makes double stranded breaks in DNA throughout the genome. B) It's function is regulated by a complementary guide RNA. C) It forms a complex with DNA. D) It removes random DNA bases. Answer: B Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-SF 63) Jennifer Doudna discovered CRISPR-Cas9 due to its role in which of the following? A) defending bacteria against bacteriophage infection B) strengthening a virus' ability to infect its host C) protecting mammalian cells against DNA virus integration D) promoting adaptation by generating random mutations Answer: A Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.5, Global LO: G1, V&C LO: VC-SF 22 Copyright © 2021 Pearson Education, Inc. 64) Using the CRISPR-Cas9 system to correct a genetic defect in a mouse brings with it which of the following risks? A) increasing the animal's susceptibility to bacteriophage infection B) decreasing the animal's ability to repair other mutations C) introducing CRISPR-Cas9 gene into the animal's genome D) altering non-target mouse genes needed for cell function Answer: D Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 5-6: Evaluating/Creating Learning Outcome: 17.5, Global LO: G2, V&C LO: VC-I 17.2 Student Edition End-of-Chapter Questions 1) In eukaryotic cells, transcription cannot begin until ________. A) the two DNA strands have completely separated and exposed the promoter B) several transcription factors have bound to the promoter C) the 5' caps are removed from the mRNA D) the DNA introns are removed from the template Answer: B Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1; Global LO: G1, V&C LO: VC-I 2) Which of the following is true of a codon? A) It never codes for the same amino acid as another codon. B) It can code for more than one amino acid. C) It can be either in DNA or in RNA. D) It is the basic unit of protein structure. Answer: C Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1; Global LO: G1, V&C LO: VC-I 3) The anticodon of a particular tRNA molecule is ________. A) complementary to the corresponding mRNA codon B) complementary to the corresponding triplet in rRNA C) the part of tRNA that bonds to a specific amino acid D) catalytic, making the tRNA a ribozyme Answer: A Topic: Translation is the RNA-directed synthesis of a polypeptide: A Closer Look Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.4; Global LO: G1, V&C LO: VC-I 23 Copyright © 2021 Pearson Education, Inc. 4) Which of the following is true of RNA processing? A) exons are cut out before mRNA leaves the nucleus B) nucleotides are added at both ends of the RNA C) ribozymes may function in the addition of a 5' cap D) RNA splicing adds a poly-A tail to the mRNA Answer: B Topic: Eukaryotic cells modify RNA after transcription Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.3; Global LO: G1, V&C LO: VC-I 5) Which component is directly involved in translation? A) RNA polymerase B) ribosome C) spliceosome D) DNA Answer: B Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 1-2: Remembering/Understanding Learning Outcome: 17.1; Global LO: G1, V&C LO: VC-I 6) Using the figure identify a 5'→ 3' sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys. A) 5'-UUUCCCAAA-3' B) 5'-GAACCCCTT-3' C) 5'-CTTCGGGAA-3' D) 5'-AAACCCUUU-3' Answer: C Topic: Genes specify proteins via transcription and translation Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.1; Global LO: G2, V&C LO: VC-I 7) Which of the following mutations would be most likely to have a harmful effect on an organism? A) a deletion of three nucleotides near the middle of a gene B) a single nucleotide deletion in the middle of an intron C) a single nucleotide deletion near the end of the coding sequence D) a single nucleotide insertion downstream of, and close to, the start of the coding sequence Answer: D Topic: Mutations of one or a few nucleotides can affect protein structure and function Bloom's Taxonomy: Levels 3-4: Applying/Analyzing Learning Outcome: 17.5; Global LO: G2, V&C LO: VC-I 24 Copyright © 2021 Pearson Education, Inc.