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79 Cards in this Set
- Front
- Back
1. DNA affects the traits of an organism by providing the instructions for synthesizing _______. |
A. proteins |
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2. Gene expression involves two phases, ___________ and translation. |
B. transcription |
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3. Messenger RNA molecules contain information that is used to synthesize ___________. |
C. polypeptides |
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4. To begin transcription, RNA polymerase must bind to a segment of DNA called the ____. |
D. promoter |
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5. The strand of DNA that is not transcribed is called the ______ strand. |
A. coding |
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6. During ________, a ribosome assembles a polypeptide whose amino acid sequence is specified by the nucleotide sequence in a molecule of mRNA. |
B. translation |
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7. The sequence of nucleotides in a DNA molecule is called the ________ code. |
D. genetic |
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8. Crick and his colleagues proposed that the genetic code consists of a series of blocks of information, called ______, each corresponding to one amino acid in an encoded protein. |
B. codons |
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9. Gene ________ refers to the combined processes of transcription and translation. |
A. expression |
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10. During transcription of mRNA in eukaryotes, some sequences are cut out of the primary transcript and the remaining sequences are joined together. This processing of mRNA is called _________. |
C. splicing |
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11. Most eukaryotic genes contain noncoding sequences called ________ that are interspersed with the coding sequences. |
A. introns |
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12. To remove noncoding sequences in the pre-mRNA of eukaryotes, multiple snRNPs combine with proteins to form a larger complex called the ___________ . |
D. spliceosome |
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13. The connection that exists between genes and hereditary traits is based on using the information encoded in genes to synthesize |
C. proteins. |
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14. Both DNA and RNA are made up of building blocks known as |
A. nucleotides. |
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15. The "one-gene/one-enzyme" hypothesis was proposed by |
E. Beadle and Tatum. |
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16. The polypeptide-making organelles, which consist of protein combined with RNA, are called |
A. ribosomes. |
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17. During translation, amino acids are carried to the ribosome by |
B. tRNA. |
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18. During _______, RNA polymerase synthesizes a molecule of RNA using DNA as a template. |
C. transcription |
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19. Which base in an anticodon will pair with the base adenine in a codon? |
D. uracil |
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20. A codon is composed of how many bases? |
C. three |
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21. In eukaryotes, translation takes place |
C. on ribosomes. |
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22. Ribosomes are complex aggregates of |
B. RNA and proteins. |
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23. The A, P, and E sites are progressively occupied by amino acids being assembled into a polypeptide. These sites are part of |
B. the large ribosomal subunit. |
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24. In eukaryotic cells, transcription occurs |
D. inside the nucleus. |
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25. In prokaryotes, the form of RNA polymerase that can accurately initiate synthesis of RNA is called |
A. the holoenzyme. |
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26. During _________, nucleotide sequence information is changed into amino acid sequence information. |
E. translation |
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27. The genetic code uses _________ nucleotide(s) to specify one amino acid. |
C. three |
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28. Which statement about the genetic code is false? |
C. Every codon codes for one amino acid. |
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29. How many unique mRNA codons can be constructed from the four different RNA nucleotides? |
E. 64 |
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30. During translation, the nucleotides that make up the mRNA are read in groups of three. These groups are called |
A. codons. |
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31. The tRNA nucleotide sequence that pairs with bases on the mRNA is called a(n) |
E. anticodon. |
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32. Ribosome movement along the mRNA is called |
D. translocation. |
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33. Specific amino acids are attached to tRNA molecules by |
A. aminoacyl-tRNA synthetases. |
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34. Codons that serve as "stop" signals for translation are recognized by |
B. release factors. |
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35. When a polypeptide is being assembled, the bond that forms between a newly added amino acid and the previous amino acid in the chain is a _________ bond. |
E. peptide |
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36. During translation in prokaryotes, formation of the initiation complex requires all of the following except |
D. RNA polymerase. |
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37. Eukaryotic mRNA molecules may contain non-coding sequences that must be removed before translation. These are called |
B. introns. |
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38. The location of translation in prokaryotic cells is |
B. on ribosomes. |
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39. In eukaryotes, pre-mRNA processing may involve all of the following except |
A. removal of exons from the pre-mRNA. |
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40. During translation, uncharged tRNA molecules leave the ribosome from the _________ site. |
A. E |
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41. The Central Dogma of biology can be stated as |
D. DNA RNA proteins. |
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42. If the sequence of bases in the template strand of a DNA molecule is 3' ATCGCTCC 5', what is the sequence of bases in the RNA that is transcribed from this molecule? |
C. 5' UAGCGAGG 3' |
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43. The template strand of a DNA segment that codes for mRNA has the sequence: ATGCGT. Which tRNA anticodons would pair with the mRNA that is coded for by this sequence? |
A. AUG CGU. |
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44. Although 61 different codons code for amino acids, cells contain fewer than 61 different tRNAs. Why? |
A. Because the 5' base on the tRNA anticodon has some flexibility (wobble); thus, some tRNA anticodons can pair with more than one mRNA codon. |
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45. Eukaryotic and prokaryotic organisms differ in how they process genetic information. Which statements best explain one of these differences? |
A. In prokaryotes, translation of the mRNA begins before transcription is complete. In eukaryotes, transcription and modification of the mRNA is completed before translation begins. |
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46. What is the first step during transcription initiation in prokaryotes? |
B. RNA polymerase binds to the promoter |
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47. Initiation of transcription differs from initiation of DNA replication in several ways. One difference is that initiation of transcription does not require |
C. a primer. |
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48. Transcription in prokaryotes is carried out by ______, which unwind(s) and transcribe(s) the gene. |
E. RNA polymerase |
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49. Eukaryotes have ____ type(s) of RNA polymerase. |
B. three |
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50. In eukaryotes, each type of RNA polymerase recognizes a different |
C. promoter |
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51. Eukaryotic pre-mRNA molecules are modified |
C. inside the nucleus. |
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52. In eukaryotes, the 3' poly-A tail is attached to |
B. mRNA. |
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53. Why are there fewer tRNA anticodons than the 61 needed to match each mRNA codon that codes for an amino acid? |
C. There is some flexibility in pairing between the 3' base of the codon and the 5' base of the anticodon. |
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54. During translation, translocation refers to |
E. moving the ribosome along the mRNA molecule. |
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55. During protein synthesis in eukaryotes, what happens during RNA splicing? |
D. The product of transcription, called the primary transcript, is cut and some pieces are joined back together to form the mature mRNA. |
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56. During protein synthesis in eukaryotes, which molecule passes from the nucleus to the cytoplasm and specifies the sequence of amino acids in the new polypeptide? |
C. mRNA |
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57. Which molecule combines with proteins to form both the large and small ribosomal subunits? |
D. rRNA |
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58. You are conducting a genetic screen to isolate nutritional mutants in yeast. Specifically, you want to isolate a double mutant that cannot synthesize histidine or leucine, two nutrients essential for growth. You start with a wild type yeast strain and mutagenize it with a UV light. Which of the following outlines the remaining steps for isolating such a mutant? |
A. Grow mutagenized yeast on rich media. Then grow them on minimal media, as well as on minimal media containing histidine, minimal media containing leucine, and minimal media containing both histidine and leucine. Select for yeast that do not grow on minimal media, do not grow on media supplemented with only histidine or leucine, but do grow on minimal media supplemented with both histidine and leucine. |
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59. Given the sentence "THE FAT CAT ATE THE RED RAT," which of the following would represent a frameshift mutation? |
C. THE FAC ATA TET HER EDR AT |
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60. What would happen if snRNAs did not recognize the branch point within an intron? |
A. A lariat would not form. |
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61. During the splicing reaction, the intron-exon junctions are recognized by |
A. snRNPs. |
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62. In prokaryotes, the RNA polymerase holoenzyme consists of |
D. the core polymerase plus a sigma subunit. |
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63. Two 6-base sequences are present in bacterial promoters: TATAAT (located 10 nt upstream from the start site) and TTGACA (located 35 nt upstream from the start site). What is the significance of the fact that these two base sequences are different? |
B. Both the location of the start site and the direction of transcription can be established. |
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64. Within the transcription bubble, the 9 most recently added nucleotides in the newly synthesized RNA strand temporarily form a helix with the template DNA strand. How might transcription be affected if helix formation did not occur? |
D. The position of the 3' end of the RNA would be unstable, inhibiting elongation. |
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65. Cells conserve energy and resources by making active proteins only when they are needed. If a protein is not needed, which of the following methods of control would be the most energy-efficient? |
A. block transcription |
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66. What is required for formation of the transcription initiation complex in eukaryotes? |
A. binding of a transcription factor to the TATA box, followed by recruitment of additional transcription factors and recruitment of RNA polymerase II |
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67. What is the likely consequence of a mutation that alters the branch point within an intron? |
B. failure to form a lariat |
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68. You are working to characterize a novel protein in mice. Analysis shows that high levels of the primary transcript that codes for this protein are found in tissue from the brain, muscle, liver, and pancreas. However, an antibody that recognizes the C-terminal portion of the protein indicates that the protein is present in brain, muscle, and liver, but not in the pancreas. What is the most likely explanation for this result? |
D. Alternative splicing in the pancreas yields a protein that is missing the portion that the antibody recognizes. |
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69. The mutation responsible for Huntington's disease is a |
D. triplet repeat expansion mutation. |
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70. How would a large chromosomal inversion affect the expression of a gene if the gene is located between the two break points but no breaks occur within the gene? |
A. The inversion would probably have no effect on gene expression. |
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71. How does DNA polymerase differ from RNA polymerase? |
D. Only DNA polymerase has a proofreading ability. |
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72. A scientist makes three artificial mRNA strands: (x) 5' AAAUUUAAAUUUAAAUUUAAAUUUAAA 3'
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C. AAA codes for lysine |
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73. A bacterial cell has a nonsense mutation that prevents it from producing a functional sigma subunit for RNA polymerase. Inability to synthesize a functional sigma subunit would have the most direct effect on |
A. transcription initiation. |
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74. What is the best way to describe our current understanding of the one-gene/one-polypeptide hypothesis? |
B. It applies to prokaryotes but not to eukaryotes. |
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75. You are attempting to synthesize rRNA in a test tube using DNA isolated from mouse cells. In addition to the template DNA, ribonucleotides, and the necessary transcription factors, you should also add _________ to the test tube. |
D. RNA polymerase I |
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76. You are studying an individual with very low levels of insulin in her blood. Further analysis indicates that cells of her pancreas are producing normal levels of this protein, but most of it is accumulating in the cytoplasm rather than being secreted from the cells. Which hypothesis to explain this observation makes the most sense? |
A. A small deletion has removed the nucleotides that code for the signal sequence at the amino terminus of the protein. |
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77. A gene that codes for a protein was removed from a eukaryotic cell and inserted into a prokaryotic cell. Although the gene was successfully transcribed and translated, it produced a different protein than it produced in the eukaryotic cell. What is the most likely explanation? |
C. Eukaryotic genes often contain introns while prokaryotic genes do not. |
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78. What is the base sequence, in the DNA template strand, of the intron that is closest to the 3' end of this strand? Shown below is a hypothetical DNA sequence from a virus. Also shown is the sequence of the RNA that is synthesized from this DNA. 78. What is the base sequence, in the DNA template strand, of the intron that is closest to the 3' end of this strand?
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B. TTACCCGGTTTA |
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79. The RNA was most likely transcribed by |
B. RNA polymerase I. |