Biology Chapter 14 Final Review
Which statement about RNA is not true? a. Transfer RNA functions in translation. b. Ribosomal RNA functions in translation. c. RNAs are produced by transcription. d. Messenger RNAs are produced on ribosomes. e. DNA codes for mRNA, tRNA, and rRNA.
d. Messenger RNAs are produced on ribosomes.
b
50. When eukaryotic DNA is hybridized with mRNA, the hybrid molecules contain loops of double-stranded DNA, which are a. retroviruses. b. introns. c. exons. d. transcripts. e. puffs.
c
51. The tail added to pre-mRNA is a. coded for by DNA. b. composed of poly T. c. important for mRNA stability. d. attached to its 5´ end. e. All of the above
e
23. The process of transcription synthesizes a. transfer RNA. b. messenger RNA. c. ribosomal RNA. d. proteins. e. a, b, and c
a
24. The region of DNA in prokaryotes to which RNA polymerase binds most tightly is the a. promoter. b. poly C center. c. enhancer. d. operator site. e. minor groove.
d
25. Promoters are made of a. proteins. b. carbohydrates. c. lipids. d. nucleic acids. e. amino acids.
b
26. A transcription start signal is called a(n) a. initiation codon. b. promoter. c. origin. d. operator. e. nonsense codon.
c
27. RNA polymerase is a. an RNA-directed DNA polymerase. b. an RNA-directed RNA polymerase. c. a DNA-directed RNA polymerase. d. a typical enzyme. e. a form of RNA.
b
1. Tuberculosis is a world health issue, killing over a million people annually. Several antibiotics have been developed to treat Mycobacterium tuberculosis, the bacterium that causes the disease. Essentially the antibiotics a. kill the bacteria directly. b. inhibit bacterial protein synthesis. c. alleviate the bloody cough, fever, and chills so the patient can recover comfortably. d. produce a lethal toxin that destroys the bacteria. e. breaks peptide bonds preventing gene expression.
a
10. How does RNA differ from DNA? a. RNA contains uracil instead of thymine and it is usually single-stranded. b. RNA contains uracil instead of thymine and it is usually double-stranded. c. RNA contains thymine instead of uracil and it is usually single-stranded. d. RNA contains uracil instead of cytosine. e. None of the above
b
11. Which of the following molecules transfers information from the nucleus to the cytoplasm? a. DNA b. mRNA c. tRNA d. Proteins e. Lipids
a
12. The link between mRNA and a protein is a. tRNA. b. a promoter. c. RNA polymerase. d. DNA polymerase. e. a start codon.
c
13. Which of the following molecules transfers information from mRNA to protein? a. DNA b. mRNA c. tRNA d. Proteins e. Lipids
c
14 The "central dogma" of molecular biology states that a. information flow between DNA, RNA, and protein is reversible. b. information flow in the cell is unidirectional, from protein to RNA to DNA. c. information flow in the cell is unidirectional, from DNA to RNA to protein. d. the DNA sequence of a gene can be predicted if we know the amino acid sequence of the protein it encodes. e. the genetic code is ambiguous but not degenerate.
b
15. The adapters that allow translation of the four-letter nucleic acid language into the 20-letter protein language are called a. aminoacyl tRNA synthetases. b. transfer RNAs. c. ribosomal RNAs. d. messenger RNAs. e. ribosomes.
d
16. Which of the following statements about the flow of genetic information is true? a. Proteins encode information that is used to produce other proteins of the same amino acid sequence. b. RNA encodes information that is translated into DNA, and DNA encodes information that is translated into proteins. c. Proteins encode information that can be translated into RNA, and RNA encodes information that can be transcribed into DNA. d. DNA encodes information that is translated into RNA, and RNA encodes information that is translated into proteins. e. None of the above
e
17. Gene expression can be regulated a. before transcription. b. during transcription and before translation. c. during translation. d. after translation. e. All of the above
a
18. Single-stranded RNA replicates by a. making an RNA strand that is complementary to the original RNA strand. b. using an adapter molecule. c. the process of transcription. d. the process of translation. e. the process of reverse transcription.
e
19. Which of the following does (do) not follow the "central dogma"? a. Yeast b. Onion cells c. Bread mold d. Skin cells e. Retroviruses
a
2. Genetic material is composed of a. DNA. b. amino acids. c. ribose. d. carbohydrates. e. lipids.
a
20. Retroviruses do not follow the "central dogma" of DNA → RNA → protein because they a. contain RNA that is used to make DNA. b. contain DNA that is used to make more RNA. c. contain DNA that is used to make tRNA. d. contain only DNA as the genetic material. e. do not contain either DNA or RNA as the genetic material.
b
21. Viruses that violate the "central dogma" through the use of an enzyme that makes DNA copies of an RNA molecule are called a. bacteriophage. b. retroviruses. c. RNA viruses. d. DNA viruses. e. enveloped viruses.
c
22. Transcription is the process of a. synthesizing a DNA molecule from an RNA template. b. assembling ribonucleoside triphosphates into an RNA molecule without a template. c. synthesizing an RNA molecule using a DNA template. d. synthesizing a protein using information from a messenger RNA. e. replicating a single-stranded DNA molecule.
c
28. DNA is composed of two strands, only one of which typically is used as a template for RNA synthesis. By what mechanism is the correct strand chosen? a. Both strands are tried, and the one that works is remembered. b. Only one strand has the start codon. c. The promoter acts to aim the RNA polymerase. d. A start factor informs the system. e. It is chosen randomly.
a
29. In bacteria, there is/are _______ RNA polymerase(s) that catalyze the synthesis of RNA from DNA. a. one b. three c. four d. five e. six
a
3. The major phenotypic expression of genotype is in a. proteins. b. tRNA. c. mRNA. d. nucleic acids. e. rRNA.
d
30. RNA polymerase uses the _______ DNA template to synthesize a _______ mRNA. a. 5´ to 3´; 5´ to 3´ b. 3´ to 5´; 3´ to 5´ c. 5´ to 3´; 3´ to 5´ d. 3´ to 5´; 5´ to 3´ e. Examples of all of the above have been found.
b
31. The direction of synthesis for a new mRNA molecule is _______ from a _______ template strand. a. 5´ to 3´; 5´ to 3´ b. 5´ to 3´; 3´ to 5´ c. 3´ to 5´; 5´ to 3´ d. 3´ to 5´; 3´ to 5´ e. 5´ to 5´; 3´ to 3´
d
32. Errors in transcription are not as potentially harmful as errors in DNA replication because a. many copies of RNA are made. b. RNA strands have a relatively short life span. c. RNA polymerases proofread and correct the errors. d. a and b are correct e. a, b, and c are correct Answer: d
b
33. The process of transcription requires a. a temporary stopping of DNA replication. b. a temporary separation of the strands in the DNA template. c. destruction of one of the strands of the DNA template. d. relaxation of positive supercoils in the DNA template. e. induction of positive supercoils in the DNA template.
a
34. There are differences in the amount of transcription that takes place for different genes. One reason for these differences is that a. some promoters are more effective at transcription initiation. b. longer genes take longer to transcribe. c. the outcome is influenced by random chance. d. ribosomes tend to attach to transcripts even before transcription is completed. e. None of the above
b
35. Termination of transcription involves a a. stop codon. b. terminator sequence. c. termiproteator. d. hairline slip. e. series of As.
b
36. There are _______ different RNA polymerases in eukaryotes. a. two b. three c. four d. five e. six
b
37. The termination of transcription is signaled by a. the stop codon. b. a sequence of nitrogenous bases. c. a protein bound to a certain region of DNA. d. rRNA. e. tRNA.
c
38. Imagine that a novel life-form is found deep within Earth's crust. Evaluation of its DNA yields no surprises. However, it is found that a codon for this life-form is just two bases in length. How many different amino acids could this organism be composed of? a. 4 b. 8 c. 16 d. 32 e. 64
e
39. How can DNA, which is made up of only four different bases, encode the information necessary to specify the workings of an entire organism? a. DNA molecules are extremely long. b. DNA molecules form codons of three bases that code for amino acids. c. The genetic code is redundant but not ambiguous. d. DNA can be replicated with low error rates. e. All of the above
e
4. Which of the following are model organisms used in biological research? a. Pea plants b. Fruit flies c. E. coli d. Bread mold e. All of the above
a
40. The stop codons code for a. no amino acid. b. methionine. c. glycine. d. halt enzyme. e. DNA binding protein.
e
41. How many codons specify amino acids? a. 20 b. 23 c. 45 d. 60 e. 61
a
42. The genetic code is best described as a. redundant but not ambiguous. b. ambiguous but not redundant. c. both ambiguous and redundant. d. neither ambiguous nor redundant. e. nonsense.
c
43. The three codons in the genetic code that do not specify amino acids are called a. missense codons. b. start codons. c. stop codons. d. promoters. e. initiator codons.
d
44. A template DNA strand has the following base sequence: 3´-GUC, CCA-5´. What would be the corresponding mRNA sequence? a. 3´-GUC, CCA-5´ b. 5´-GUC, CCA-5´ c. 3´-CAG, GGU-5´ d. 5´-CAG, GGU-3´ e. 5´-CAG, GGT-3´
e
45. Poly uracil codes for a. three different amino acids. b. poly tryptophan. c. mRNA. d. a fatty acid. e. phenylalanine.
a
46. Exons are a. translated. b. found in most prokaryotic genes. c. removed during RNA processing. d. Both a and b e. Both a and c
b
47. Exons are a. spliced out of the original transcript. b. spliced together from the original transcript. c. spliced to introns to form the final transcript. d. much larger than introns. e. larger than the original coding region.
d
48. The regions of DNA in a eukaryotic gene that contain noncoding base sequences are called a. enhancers. b. mRNAs. c. hnRNAs. d. introns. e. leader sequences.
e
49. Nucleic acid hybridization a. is used to study the relationship between eukaryotic genes and their transcripts. b. requires that the original DNA molecule be denatured. c. involves the use of a probe to form a double-stranded molecule. d. originally revealed the existence of introns. e. All of the above
a
5. After irradiating Neurospora, Beadle and Tatum collected mutants that would a. not grow on a minimal medium but would grow on a minimal medium with arginine. b. grow on any minimal medium. c. not grow on any minimal medium. d. grow on a minimal medium but would not grow on a minimal medium with arginine. e. None of the above
c
52. The guanosine triphosphate (GTP) cap that is added to the 5´ end of primary mRNA a. contains all the coding and noncoding sequences of the DNA template. b. provides the mRNA molecule with a poly A tail. c. facilitates the binding of mRNA to ribosomes. d. forms hydrogen bonds. e. helps transfer amino acids to the ribosomes.
a
53. The modified G cap on eukaryotic mRNAs is found a. at the 5´ end. b. at the 3´ end. c. in the consensus sequence. d. in the poly A tail. e. in snRNA.
a
54. Poly A tails a. are added after transcription. b. are encoded by a sequence of thymines in the DNA. c. are found in all mRNAs. d. have no function. e. are removed during RNA processing.
c
55. Chromosomes of eukaryotic DNA must have a. DNA sequences that make up telomeres and centromeres. b. proteins that are centromeres and DNA that form telomeres. c. a 5´ G cap. d. an inactivation center. e. None of the above
b
56. Which of the following is not part of RNA processing in eukaryotes? a. Splicing of exons b. Reverse transcription c. Addition of a 5´ cap d. Addition of a poly A tail e. Intron removal
e
57. What are the three processes that must be completed before transcripts can be translated in eukaryotes? a. Binding of snRNPs, addition of a poly A tail, splicing of introns b. Binding of snRNPs, transporting, synthesizing of ribose c. Capping, transporting, synthesizing of ribose d. Binding of snRNPs, capping, splicing e. Splicing, capping, addition of a poly A tail
e
58. RNA processing in eukaryotes involves the a. addition of a G cap. b. addition of a poly A tail. c. removal of introns. d. splicing of exons. e. All of the above
b
59. snRNPs are a. exon-intron boundary regions. b. small nuclear ribonucleoprotein particles. c. protein fragments removed from snRNA molecules. d. signal ribosomal nuclear proteins. e. glucose-conjugated trapezoids.
b
6. Within a group of mutants with the same growth requirement (i.e., the same overt phenotype), mapping studies determined that individual mutations were on different chromosomes. This indicates that a. the same gene governs all the steps in a particular biological pathway. b. different genes can govern different individual steps in the same biological pathway. c. different genes govern the same step in a particular biological pathway. d. all biological pathways are governed by different genes. e. genes do not govern steps in biological pathways.
d
60. The binding of snRNPs to consensus sequences is necessary for a. gene duplication. b. the addition of a poly A tail. c. capping an hnRNA. d. RNA splicing. e. transcription.
b
61. Consensus sequences (short segments of DNA) appear in the boundaries between introns and exons of various genes. These sequences appear to be involved in a. directing the polymerases to the appropriate place on the DNA for transcription to begin. b. the splicing of introns out of the DNA. c. allowing the transcription to stop at the appropriate spot. d. catalyzing the synthesis of a protein. e. None of the above
b
62. The conformation of tRNA is maintained by a. peptide bonds. b. hydrogen bonds. c. disulfide bridges. d. phosphodiester bonds. e. glycosidic linkages.
e
63. Activating enzymes a. are sometimes referred to as the second genetic code. b. link the right tRNAs and amino acids. c. are also known as aminoacyl-tRNA synthetases. d. are specific for one amino acid. e. All of the above
d
64. What events must take place to ensure that the protein made is the one specified by mRNA? a. tRNA must read mRNA correctly. b. tRNA must carry the amino acid that is correct for its reading of the mRNA. c. Covalent bonding between the base pairs must occur. d. Both a and b e. All of the above
d
65. A sequence of three RNA bases can function as a. a codon. b. an anticodon. c. a gene. d. Both a and b e. Both a and c
d
66. The difference between mRNA and tRNA is that a. tRNA has a more elaborate three-dimensional structure. b. tRNAs are usually much smaller than mRNAs. c. mRNA carries amino acids. d. Both a and b e. None of the above
b
67. How is it possible for single-stranded RNA to fold into complex shapes? a. Phosphodiester linkages form between the phosphate and the sugar ribose. b. Internal base pairings make this possible: adenine with uracil and cytosine with guanine. c. Uracil's methyl group binds to adenine, spiraling the molecule. d. The single strand "twists" around itself. e. The RNA binds to proteins, creating a conformation (three-dimensional shape).
a
68. Fewer different tRNA molecules exist than might have been expected for the complexity of its function. This is possible because a. the third position of the codon does not have to pair conventionally. b. the second position of the codon does not have to pair conventionally. c. the anticodon does not have the conventional bases. d. there are fewer amino acids than there are possible codons. e. the code is degenerating.
e
69. Which of the following statements about codons and anticodons is true? a. The codon bonds covalently with the anticodon. b. The base sequences are the same. c. There are 64 codons and 61 anticodons. d. Activating enzymes link codons and anticodons. e. At contact, the codon and the anticodon are antiparallel to each other.
d
7. The study of Neurospora mutants grown on various supplemented media led to a. a determination of the steps in biological pathways. b. the one-gene, one-enzyme hypothesis. c. the idea that genes are "on" chromosomes. d. Both a and b e. Both a and c
d
70. The enzyme that charges the tRNA molecules with appropriate amino acids is a. tRNA chargeatase. b. amino tRNA chargeatase. c. transcriptase. d. aminoacyl-tRNA synthetase. e. None of the above
b
71. Ribosomes are a collection of _______ that are needed for _______. a. small proteins; translation b. proteins and small RNAs; translation c. proteins and tRNAs; transcription d. proteins and mRNAs; translation e. mRNAs and tRNAs; translation
a
72. During translation initiation, the first site occupied by a charged tRNA is the a. A site. b. B site. c. large subunit. d. T site. e. P site.
a
73. The formation of a peptide bond between an amino acid at the P site and an amino acid at the A site during translation is catalyzed by a. the large ribosomal subunit. b. a specialized segment of DNA. c. a specialized segment of RNA. d. the initiation complex. e. initiation factors.
b
74. During translation elongation, the existing polypeptide chain is transferred to a. the tRNA occupying the A site. b. the tRNA occupying the P site. c. the ribosomal rRNA. d. a signal recognition particle. e. None of the above
a
75. mRNA is synthesized in the _______ direction, which corresponds to the _______ of the protein. a. 5´ to 3´; N terminus to C terminus b. 3´ to 5´; C terminus to N terminus c. 5´ to 3´; C terminus to N terminus d. 3´ to 5´; N terminus to C terminus e. Examples of all of the above have been found.
a
76. Proteins are synthesized from the _______, in the _______ direction along the mRNA. a. N terminus to C terminus; 5´ to 3´ b. C terminus to N terminus; 5´ to 3´ c. C terminus to N terminus; 3´ to 5´ d. N terminus to C terminus; 3´ to 5´ e. N terminus to N terminus; 5´ to 5´
c
77. In protein synthesis, the endoplasmic reticulum a. is the site where mRNA attaches. b. is the site where all ribosomes bind. c. is the site of translation of membrane-bound and exported proteins. d. produces tRNAs. e. brings together mRNA and tRNA.
a
78. Which of the following is the correct order of events by which a protein is delivered to its cellular destination? a. A signal sequence binds to a docking protein, a membrane channel is formed, chaperonins unfold the protein, the protein enters the organelle, and the protein refolds. b. A membrane channel is formed, a signal sequence binds to a docking protein, chaperonins unfold the protein, the protein enters the organelle, and the protein refolds. c. Chaperonins unfold the protein, a signal sequence binds to a docking protein, a membrane channel is formed, the protein enters the organelle, and the protein refolds. d. A membrane channel is formed, chaperonins unfold the protein, a signal sequence binds to a docking protein, the protein enters the organelle, and the protein refolds. e. A signal sequence binds to a docking protein, a transmembrane-gated channel opens, and the protein enters the organelle.
d
79. In eukaryotes, ribosomes become associated with endoplasmic reticulum membranes when a. a signal sequence on the mRNA interacts with a receptor protein on the membrane. b. a signal sequence on the ribosome interacts with a receptor protein on the membrane. c. a signal sequence at the amino terminus of the protein being synthesized interacts with a receptor protein on the ribosome. d. a signal sequence on the protein being synthesized interacts with a signal recognition particle and both bind to the endoplasmic reticulum. e. the messenger RNA passes through a pore in the membrane.
e
8. The classic work of Beadle and Tatum, later refined by others, provided evidence for the a. one-gene, one-enzyme hypothesis. b. one-gene, one-polypeptide hypothesis. c. mechanism by which information in genes is translated into traits. d. effects of some mutations on organisms. e. All of the above
b
80. The addition of sugar residues to the protein after translation is called a. glycation. b. glycosylation. c. phosphorylation. d. proteolysis. e. exonuclease digestion.
d
81. After translation, some proteins are processed by _______, which is cleavage of the protein to make a shortened finished protein. a. glycation b. glycosylation c. phosphorylation d. proteolysis e. exonuclease digestion
d
82. In eukaryotic cells, proteins that contain covalently attached sugar residues are translated a. in the nucleus. b. in the cytoplasm. c. in mitochondria. d. on the endoplasmic reticulum. e. on the Golgi apparatus.
d
9. Genes code for a. enzymes. b. polypeptides. c. RNA. d. All of the above e. None of the above
An mRNA sequence is 5′-CAGUUACGA...UAAGC-3′ (dots are intervening sequences). What is the sequence of the template strand of DNA? A: 3′-GTCAATGCT...ATTCG-5′ B: 5′-CAGTTACGA...TAAGC-3′ C: 5′-CAGUUACGA...UAAGC-3′ D: 5′-GTCAATGCT...ATTCG-3′ E: 3′-CAGUUACGA...UAAGC-5′
A: 3′-GTCAATGCT...ATTCG-5′
Which of the following statements about the flow of genetic information is true? A: DNA encodes information that is transcribed into RNA, and RNA encodes information that is translated into proteins. B: DNA encodes information that is translated directly to proteins, without any intermediaries. C: Proteins encode information that is used to produce other proteins of the same amino acid sequence. D: Proteins encode information that can be translated into RNA, and RNA encodes information that can be transcribed into DNA. E: RNA encodes information that is transcribed into DNA, and DNA encodes information that is translated into proteins.
A: DNA encodes information that is transcribed into RNA, and RNA encodes information that is translated into proteins.
Which of the following statements about RNA is incorrect? A: RNA molecules are synthesized in the 3'-5' direction B: Only mRNA molecules contain the information for making proteins C: RNA is single-stranded but some RNA molecules form complex 3-dimensional shapes by intra-molecular base pairing. D: RNA has a U (instead of a T) and the U base pairs with A in other nucleic acid molecules.
A: RNA molecules are synthesized in the 3'-5' direction
Which of the following about transfer RNAs (tRNAs) is false? A: They can interchange the amino acids they bind. B: They interact with ribosomes. C: ATP is required for the charging of tRNAs with amino acids. D: They are the adapter molecules proposed by Crick. E: They interact with mRNA.
A: They can interchange the amino acids they bind.
In the elongation stage of translation, A: rRNA is catalytically active. B: the polypeptide chain grows from a C-terminus to N-terminus direction. C: the message is read in a 3′-to-5′ direction. D: tRNA is catalytically active. E: peptidyl transferase activity is catalyzed by a ribosomal protein.
A: rRNA is catalytically active.
RNA polymerases differ from DNA polymerases in that: A: DNA polymerases are in the nucleus of eukaryotic cells and RNA polymerases are in the cytoplasm. B: RNA polymerases do not have a proofreading function, whereas DNA polymerases do. C: RNA polymerases do not require a template, whereas DNA polymerases do. D: RNA polymerases use deoxyribonucleoside triphosphates as substrates, whereas DNA polymerases use ribonucleoside triphosphates. E: DNA polymerases are processive; RNA polymerases are not.
B: RNA polymerases do not have a proofreading function, whereas DNA polymerases do.
Which of the following statements is incorrect about tRNA? A: There is at least one specific tRNA for every amino acid. B: There are 61 different tRNAs because there are 61 codons for amino acids. C: All tRNAs have a triplet anticodon that is complementary and anti-parallel to a codon in mRNA. D: tRNAs interact with both mRNA and the ribosome.
B: There are 61 different tRNAs because there are 61 codons for amino acids.
The genetic code: A: excludes start and stop codons. B: is considered redundant. C: has only one codon that represents glycine. D: differs considerably among various organisms. E: is considered ambiguous.
B: is considered redundant.
Order the four steps given below, from beginning to end, that would occur during expression of the eukaryotic gene rbcS. (1) Pre-mRNA is processed to make mRNA. (2) Ribosomes translate the mRNA message to make proteins. (3) mRNA is transported to the cytoplasm. (4) DNA is used as a template make pre-mRNA. A: 1, 4, 3, 2 B: 4, 1, 2, 3 C: 4, 1, 3, 2 D: 4, 3, 1, 2 E: 1, 2, 4, 3
C: 4, 1, 3, 2
Which of the following is primarily responsible for producing the phenotype of an organism? A: Nucleic acids B: mRNA C: Proteins D: rRNA E: tRNA
C: Proteins
Which of the following processes can occur simultaneously in prokaryotic cells? A: Transcription and RNA processing B: RNA processing and translation C: Transcription and translation D: All of the above.
C: Transcription and translation
If the codon is 5′-GAA-3′', then the corresponding anticodon is: A: 5′-CUU-3′. B: 3′-CTT-5′. C: 5′-GAA-3′. D: 3′-CUU-5′. E: 3′-GAA-5′.
D: 3′-CUU-5′.
If the coding region of an mRNA is 2400 nucleotides long, how many codons does it have? A: 7200 B: 2400 C: 600 D: 800 E: 1200
D: 800
The study of Neurospora mutants grown on various supplemented media led to: A: a determination of the steps in biological pathways. B: the one-gene, one-enzyme hypothesis. C: the idea that genes are "on" chromosomes. D: Both a and b E: Both a and c
D: Both a and b
In eukaryotic cells, translation occurs in the _______ and transcription occurs _______. A: nucleus; outside of the cell B: nucleus; in the nucleus C: nucleus; in the cytoplasm D: cytoplasm; in the nucleus E: cytoplasm; outside of the cell
D: cytoplasm; in the nucleus
The start codon is near the _______ end of the mRNA, and this corresponds with the _______ terminus of the polypeptide. A: 3′; N B: 3′; C C: 3′; T D: 5′; C E: 5′; N
E: 5′; N
Which of the following statements about the Genetic Code is/are true? A: It is non-overlapping: three letters are read, then the next three and so on. B: Each codon specifies only one amino acid. C: Each codon specifies a different amino acid. D: Each codon can specify more than one amino acid. E: A and B F: A, B and C G: A and D
E: A and B
Which of the following statements about pre-mRNA splicing is false? A: It removes introns in eukaryotic genes. B: It is performed by small nuclear ribonucleoprotein particles (snRNPs). C: It is directed by consensus sequences. D: It shortens the RNA molecule. E: It is common in prokaryotes.
E: It is common in prokaryotes.
Which of the following are made in the nucleus of eukaryotic cells? A: pre-mRNA B: mature processed mRNA C: tRNA D: rRNA E: Polypeptides F: A, C and D G: A, B, C and D H: All of the above
G: A, B, C and D
Which of the following does not occur after eukaryotic mRNA is transcribed? a. Binding of a sigma factor to the promoter b. Capping of the 5′ end c. Addition of a poly A tail to the 3′ end d. Splicing out of the introns e. Transport to the cytosol
a. Binding of a sigma factor to the promoter
Which statement about translation is not true? a. Translation is RNA-directed polypeptide synthesis. b. An mRNA molecule can be translated by only one ribosome at a time. c. The same genetic code operates in almost all organisms and organelles. d. Energy is used in the formation of the bond between a tRNA and an amino acid. e. There are both start and stop codons.
b. An mRNA molecule can be translated by only one ribosome at a time.
The adapters that allow translation of the four-letter nucleic acid language into the 20-letter protein language are called a. aminoacyl-tRNA synthase. b. transfer RNAs. c. ribosomal RNAs. d. messenger RNAs. e. ribosomes.
b. transfer RNAs.
Normally, Neurospora can synthesize all 20 amino acids. A certain strain of this mold cannot grow in minimal nutritional medium, but grows only when the amino acid leucine is added to the medium. This strain a. is dependent on leucine for energy. b. has a mutation affecting a biochemical pathway leading to the synthesis of carbohydrates. c. has a mutation affecting the biochemical pathways leading to the synthesis of all 20 amino acids. d. has a mutation affecting the biochemical pathway leading to the synthesis of leucine. e. has a mutation affecting the biochemical pathways leading to the syntheses of 19 of the 20 amino acids.
d. has a mutation affecting the biochemical pathway leading to the synthesis of leucine.
The genetic code a. is different for prokaryotes and eukaryotes. b. has changed during the course of recent evolution. c. has 64 codons that code for amino acids. d. has more than one codon for many amino acids. e. is ambiguous.
d. has more than one codon for many amino acids.
Transcription a. produces only mRNA. b. requires ribosomes. c. requires tRNAs. d. produces RNA growing from the 5′ end to the 3′ end. e. takes place only in eukaryotes.
d. produces RNA growing from the 5′ end to the 3′ end.
An mRNA has the sequence 5′-AUGAAAUCCUAG-3′. What is the template DNA strand for this sequence? a. 5′-TACTTTAGGATC-3′ b. 5′-ATGAAATCCTAG-3′ c. 5′-GATCCTAAAGTA-3′ d. 5′-TACAAATCCTAG-3′ e. 5′-CTAGGATTTCAT-3′
e. 5′-CTAGGATTTCAT-3′
