Ch 10, 11 &14 Preview

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1 Ch 10, 11 &14 Preview Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Why did the original one-gene, one-enzyme hypothesis have to be modified? a. Some RNAs have catalytic activity. b. Not all proteins are coded by genes. c. Some enzymes are made up of more than one polypeptide. d. All genes code for multiple enzymes. e. Not all enzymes are coded for by genes. 2. Sickle-cell disease and hemoglobin C disease are both caused by point mutations, resulting in glutamic acid being replaced by and, respectively. a. valine; lysine b. lysine; arginine c. serine; cysteine d. valine; glycine e. serine; a stop codon 3. Which of the following is required for the initiation of transcription? a. The start codon AUG b. Promoter DNA c. Ribonucleoside triphosphates d. Terminator DNA e. DNA polymerase 4. Put the following four steps of eukaryotic gene expression in order, from beginning to end. (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; 3; 1; 2 c. 4; 1; 3; 2 d. 4; 1; 2; 3 e. 1; 2; 4; 3 5. RNA polymerases differ from DNA polymerases in that a. RNA polymerases do not require a template. b. RNA polymerases use deoxyribonucleoside triphosphates as substrates. c. DNA polymerases use ribonucleoside triphospates as substrates. d. RNA polymerases are less effective at proofreading than DNA polymerases. e. only DNA polymerases are processive. 6. Which of the following statements about pre-mrna splicing is false? a. It removes introns. b. It is performed by small nuclear ribonucleoprotein particles (snrnps). c. It is common in prokaryotes. d. It is directed by consensus sequences. e. It shortens the RNA molecule.

2 7. Which component of transcribed RNA in eukaryotes is present in the primary transcript but is removed before translation occurs? a. Intron b. 5' cap c. Ribosome binding site d. Poly A tail e. Exon 8. In eukaryotes, the first amino acid in a growing polypeptide chain is always because the only codon for this amino acid is also the codon. a. methionine; start b. tryptophan; stop c. alanine; start d. alanine; stop e. tryptophan; start 9. Which of the following single-base substitutions in the template strand of DNA would result in the premature termination of translation? a. CAA to CAG b. CCT to CCC c. ATG to ATT d. GAG to TAG e. CTG to CTT 10. UAU and UAC both code for tyrosine. A change from UAU to UAC would thus be a(n) mutation; a change from UAU to UAG would be a(n) mutation. a. silent; missense b. nonsense; silent c. frame-shift; missense d. silent; nonsense e. nonsense; frame-shift 11. Ribosomes a. are not found in prokaryotes. b. carry genetic information. c. carry out translation. d. contain RNA only. e. have no role in the fidelity of mrna and trna interactions. 12. The mrna codon for leucine is 5 -UUG-3, and the trna anticodon is a. 5'-UUG-3'. b. 3'-UUG-5'. c. 5'-TTC-3'. d. 5'-AAC-3'. e. 3'-AAC-5'. 13. Which of the following statements about trnas is false? a. Specific enzymes bind amino acids to their corresponding trnas. b. trnas have an anticodon at their 5' end and an amino acid attachment site at their 3' end. c. trnas interact with mrna. d. trnas interact with ribsomes. e. ATP is required for the charging of trnas with amino acids.

3 14. During protein synthesis, ribosomes a. translate mrna into DNA. b. transcribe mrna to proteins. c. translate mrna into trna. d. translate mrna into polypeptides. e. transcribe DNA into mrna. 15. At the initiation of translation in eukaryotes, a. the complex of mrna and the large ribosomal subunit are formed. b. the anticodon of trna charged with methionine binds to mrna associated with the small ribosomal subunit. c. the large ribosomal subunit binds to mrna, causing the release of the small subunit. d. the large ribosomal subunit binds to the complex before the methionine-charged trna. e. the poly A tail of mrna is directly involved. 16. Which of the following is not involved in the elongation step of translation? a. Peptidyl transferase b. Charged trna c. Ribosomes d. The amino acid site e. RNA polymerase 17. In the elongation stage of translation, a. the message is read in the 3'-to-5' direction. b. the polypeptide chain grows from the Trp to the Met direction. c. peptidyl transferase activity is catalyzed by a ribosomal protein. d. rrna plays a passive role. e. rrna is catalytically active. 18. A protein destined for a lysosome carries a signal peptide for the a. lysosome. b. mitochondria. c. nucleus. d. rough ER. e. plasma membrane. 19. Posttranslational alterations of proteins a. can affect the activity of an enzyme. b. may include addition of phosphate groups. c. may include the addition of polysaccharides to proteins. d. may include the cleavage of signal sequences. 20. Predict the intracellular destinations of the following proteins: DNA polymerase; pyruvate kinase; rubisco; citrate synthase. a. Nucleus; mitochondrion; chloroplast; cytoplasm b. Nucleus; cytoplasm; chloroplast; mitochondrion c. Cytoplasm; chloroplast; mitochondrion; nucleus d. Cytoplasm; chloroplast; nucleus; mitochondrion e. Mitochondrion; chloroplast; nucleus, cytoplasm 21. Gene expression can be a. regulated before transcription.

4 b. during transcription. c. after transcription but before translation. d. at or after translation. 22. genes are expressed all of the time. a. Inducible b. Repressed c. Activator d. Constitutive e. Clustered 23. Bacterial viruses (phage) a. can reproduce on their own. b. require a host cell to replicate. c. carry out metabolism. d. have a plasma membrane. e. are alive. 24. Regulation of gene expression during the phage lytic cycle does not include a. binding of a host RNA polymerase to a viral promoter. b. stimulation of viral late gene transcription. c. enhancement of the host s gene transcription. d. enhancement of viral early gene transcription. e. down regulation of the host s gene transcription. 25. A retrovirus a. has a double-stranded DNA genome. b. has a single-stranded DNA genome. c. has a double-stranded RNA genome. d. encodes a reverse transcriptase. e. integrates its genome directly into the host s genome. 26. Structural genes a. code for structural proteins. b. are regulatory regions of DNA. c. specify the primary structure (amino acid sequence) of proteins. d. are always constitutively expressed. e. are absent in eukaryotes. 27. Operons a. are common in eukaryotes. b. consist of structural genes only. c. consist of a promoter, an operator, structural genes, and a repressor gene. d. consist of a promoter, an operator, and two (or more) structural genes. e. include inducer genes. 28. A(n) operon is turned off unless needed. a. repressible b. constitutive c. inducible d. clustered e. None of the above

5 29. A(n) operon is turned on unless not needed. a. repressible b. constitutive c. inducible d. clustered e. None of the above 30. The expression of the lac structural genes is when lactose is absent from the culture medium and is when lactose is added because lactose binds to the and inactivates it. a. low; high; lac repressor b. high; low; lac inducer c. low; high; lac promoter d. high; low; lac operator e. low; high; lac operator 31. are present in prokaryotes and bind to and direct the polymerase to specific promoters. a. Sigma factors b. Sporulation proteins c. Reverse transcriptatses d. Proteases e. Ribosomes 32. Prokaryotes and eukaryotes differ in transcription in that a. there are three RNA polymerases in eukaryotes. b. initiation of transcription is simpler in prokaryotes. c. structural genes for a pathway are more likely to be clustered in prokaryotes. d. eukaryotic promoters have a TATA box. 33. Which of the following statements about RNA polymerase is true? a. Bacteria use RNA polymerase III to transcribe trna and mrna. b. Eukaryotes use different RNA polymerases to transcribe rrna and mrna. c. In eukaryotes, RNA polymerase II binds directly to the DNA promoter and initiates transcription. d. Bacteria contain more regulatory sequences than eukaryotes. e. Eukaryotes use RNA polymerase III to transcribe ribosomal RNA. 34. In the initiation of the transcription of protein-coding genes in eukaryotes, cannot bind directly to the. Initiation requires and other regulatory proteins called. a. RNA polymerase I; TATA box; TFIID; transcription factors b. RNA polymerase II; initiation site; TFIID; transcription factors c. RNA polymerase III; initiation site; TFIID; initiation factors d. RNA polymerase I; TATA box: initiation factors; TFIID e. TFIID; RNA polymerase I; initiation site; transcription factors 35. Which of the following are not involved in the process of transcription? a. RNA polymerase b. Transcription factors c. Promoters d. TATA box e. Ribosomes

6 36. DNA methylation a. is important in the development of mammalian embryos. b. may repress the transcription of genes. c. involves the modification of the pyrimidine cytosine. d. is abundant in promoters. 37. Epigenetics may be defined as changes in the expression of a gene or set of genes by and. a. transcription factors; DNA methylation b. chromosomal protein alteration; transcription factors c. DNA methylation; chromosomal protein alteration d. promoters; DNA methylation e. promoters; chromosomal protein alteration 38. Which of the following does not regulate gene expression after transcription? a. MicroRNA b. Translational repressor proteins c. Modifications to the G cap d. Alternative splicing regulate gene expression. 39. An enzyme adds a(n) tag to proteins that are recognized by proteasomes for destruction. a. methionine b. lactate c. ubiquitin d. phosphate e. methyl 40. Predict what would happen to the synthesis of the enzyme HMG CoA reductase (an enzyme that catalyzes an initial step in the synthesis of cholesterol) if trichostatin A, a histone deacetylase inhibitor, is added to liver cells. a. The amount of HMG CoA reductase increases. b. The amount of HMG CoA reductase decreases. c. The HMG CoA reductase levels do not change. d. The HMG CoA reductase undergoes a conformational change and loses function. e. None of the above 41. Which of the following statements about determination is false? a. Determination precedes differentiation. b. Most cells are determined early in their life cycle. c. A determined cell will keep its determination no matter where it is placed in an embryo. d. One cannot tell whether a cell is determined by its appearance. e. Fates of cells become more restricted during development. 42. The process of morphogenesis a. is the shaping of differentiated cells into the multicellular body and its organs. b. sets the developmental fate of a cell. c. is the process by which different cell types arise. d. is the increase in body size. 43. Although plants may be cloned from somatic cells, animals have so far been cloned using either cells or by with eggs.

7 a. differentiated; nuclear transfer; cell fusion; nucleated b. determined; nuclear transfer; cell fusion; enucleated c. differentiated; nuclear transfer; cell fusion; enucleated d. embryonic; transformation; nuclear transfer; nucleated e. differentiated; transformation; cell fusion; enucleated 44. Stem cells are a. present in all parts of a mature plant. b. likely to be present in animal tissues that do not regenerate. c. totipotent in animals. d. multipotent in animals. e. found in just a few animal tissues. 45. Induced pluripotent stem cells a. are genetic transformants. b. may be produced from skin cells in vitro. c. can be induced to form many different tissues. d. offer some advantages over embryonic stem cells for therapeutic use. 46. In a vertebrate embryo, a. cell division and differentiation may be mutually exclusive. b. arrest of the cell cycle blocks differentiation. c. transcription factors result in differential gene expression. d. rapid growth by cell division favors differentiation. e. Both a and c 47. The fate of a cell during development is a. entirely controlled by nuclear gene expression. b. influenced by cytoplasmic determinants. c. independent of gene expression. d. not altered by reagents that interfere with microtubule formation. e. determined solely by inducers. 48. Apoptosis a. is random cell death. b. is not an important process in the development of nematodes. c. is not an important process in neuronal development of humans. d. occurs by similar mechanisms in both nematodes and humans. e. is a process controlled by a single gene. 49. The genes that determine the fate of cells in the of a flowering plant s shoot apex are called genes. These genes code for. a. meristem; organ identity; transcription factors b. whorl; homeotic; transcription factors c. meristem; homeotic; morphogens d. whorl; organ identity; morphogens e. meristem; organ identity; LEAFY protein 50. Location of a cell may be critical in the determination of its ultimate fate during development, as in the development of vertebrate limbs. This fact arises from a. the unequal distribution of transcription factors. b. expression of organ identity genes.

8 c. a gradient in the concentration of the morphogen, Sonic hedgehog. d. a gradient in the concentration of ZPA. e. expression of homeotic genes. 51. In Drosophila, the bicoid and nanos genes a. are expressed late in the development of the embryo. b. determine the dorsal ventral axis of the embryo. c. are expressed even before fertilization. d. are expressed uniformly within the egg. e. have no effect on the expression of the hunchback gene. 52. The anterior and posterior ends of a Drosophila embryo are determined by genes that are active fertilization and result in a gradient of the protein. a. maternal effect; before and after; Hunchback b. segmentation; before and after; Bicoid c. organ identity; before and after; Nanos d. maternal effect; before; Hunchback e. organ identity; after; Hunchback 53. Which of the following is the last set of genes to turn on in the Drosophila embryo? a. Segment polarity genes b. Homeotic genes c. Maternal effect genes d. Gap genes e. Pair rule genes 54. A homeobox a. is a protein sequence. b. is another name for a homeodomain. c. binds to DNA. d. is a DNA sequence present in many transcription factors. e. is not present in plants. 55. Which of the following principles of evo-devo is not stated properly? a. Even distantly related organisms share similar molecular mechanisms for development. b. New developmental mechanisms, rather than modifications of existing mechanisms, account for morphological evolution. c. Developmental mechanisms have evolved to be responsive to environmental cues. d. Development is modular. e. Changing the timing of gene expression during development can lead to new body forms. 56. Hox genes a. are present in single copies. b. control dorsal ventral pattern formation in Drosophila. c. code for enzymes. d. are clustered in a similar way in both Drosophila and mouse embryos. e. code for termination factors. 57. Developmental modularity a. allows one part of an animal s body to change independent of another part. b. is controlled by a single switch. c. is a consequence of the action of the genetic toolkit. d. does not involve spatial differences in gene expression.

9 e. Both a and c 58. Major morphological changes can result from a. mutations in developmental regulatory genes. b. short-term environmental changes. c. alterations in the time or place of expression of genes. d. Both a and c 59. Conserved developmental genes can lead to evolution. a. divergent b. convergent c. parallel phenotypic d. linear e. None of the above 60. Evolutionary modifications a. generally occur in large steps. b. are facilitated by the conservation of the genes that regulate development. c. result from rapid mutations of the genes that control development. d. usually result in entirely new anatomical features over a short time period. e. such as wings, likely evolved independently in insects and vertebrates.

10 Ch 10, 11 &14 Preview Answer Section MULTIPLE CHOICE 1. ANS: C PTS: 1 REF: Page TOP: Concept 10.1 Genetics Shows That Genes Code for Proteins 2. ANS: A PTS: 1 REF: Page 189 TOP: Concept 10.1 Genetics Shows That Genes Code for Proteins 3. ANS: B PTS: 1 REF: Page TOP: Concept 10.2 Translation of the Genetic Code Is Mediated by trna and Ribosomes 4. ANS: C PTS: 1 REF: Page TOP: Concept 10.2 DNA Expression Begins with Its Transcription to RNA SKL: 3. Applying 5. ANS: D PTS: 1 REF: Page 192 TOP: Concept 10.2 DNA Expression Begins with Its Transcription to RNA 6. ANS: C PTS: 1 REF: Page TOP: Concept 10.2 DNA Expression Begins with Its Transcription to RNA 7. ANS: A PTS: 1 REF: Page TOP: Concept 10.2 DNA Expression Begins with Its Transcription to RNA 8. ANS: A PTS: 1 REF: Page 197 TOP: Concept 10.3 The Genetic Code in RNA Is Translated into the Amino Acid Sequences of Proteins 9. ANS: C PTS: 1 REF: Page TOP: Concept 10.3 The Genetic Code in RNA Is Translated into the Amino Acid Sequences of Proteins 10. ANS: D PTS: 1 REF: Page TOP: Concept 10.3 The Genetic Code in RNA Is Translated into the Amino Acid Sequences of Proteins SKL: 3. Applying 11. ANS: C PTS: 1 REF: Page 199 TOP: Concept 10.4 Translation of the Genetic Code Is Mediated by trna and Ribosomes 12. ANS: E PTS: 1 REF: Page TOP: Concept 10.4 Translation of the Genetic Code Is Mediated by trna and Ribosomes SKL: 3. Applying 13. ANS: B PTS: 1 REF: Page TOP: Concept 10.4 Translation of the Genetic Code Is Mediated by trna and Ribosomes 14. ANS: D PTS: 1 REF: Page TOP: Concept 10.4 Translation of the Genetic Code Is Mediated by trna and Ribosomes 15. ANS: B PTS: 1 REF: Page

11 TOP: Concept 10.4 Translation of the Genetic Code Is Mediated by trna and Ribosomes 16. ANS: E PTS: 1 REF: Page 202 TOP: Concept 10.4 Translation of the Genetic Code Is Mediated by trna and Ribosomes 17. ANS: E PTS: 1 REF: Page 202 TOP: Concept 10.4 Translation of the Genetic Code Is Mediated by trna and Ribosomes 18. ANS: D PTS: 1 REF: Page TOP: Concept 10.5 Proteins Are Modified after Translation 19. ANS: E PTS: 1 REF: Page TOP: Concept 10.5 Proteins Are Modified after Translation 20. ANS: B PTS: 1 REF: Page TOP: Concept 10.5 Proteins Are Modified after Translation 21. ANS: E PTS: 1 REF: Page 209 TOP: Concept 11.1 Several Strategies Are Used to Regulate Gene Expression 22. ANS: D PTS: 1 REF: Page 209 TOP: Concept 11.1 Several Strategies Are Used to Regulate Gene Expression 23. ANS: B PTS: 1 REF: Page 210 TOP: Concept 11.1 Several Strategies Are Used to Regulate Gene Expression 24. ANS: C PTS: 1 REF: Page TOP: Concept 11.1 Several Strategies Are Used to Regulate Gene Expression 25. ANS: D PTS: 1 REF: Page 211 TOP: Concept 11.1 Several Strategies Are Used to Regulate Gene Expression 26. ANS: C PTS: 1 REF: Page 213 TOP: Concept 11.2 Many Prokaryotic Genes Are Regulated in Operons 27. ANS: D PTS: 1 REF: Page 213 TOP: Concept 11.2 Many Prokaryotic Genes Are Regulated in Operons SKL: 3. Applying 28. ANS: C PTS: 1 REF: Page 213 TOP: Concept 11.2 Many Prokaryotic Genes Are Regulated in Operons 29. ANS: A PTS: 1 REF: Page 213 TOP: Concept 11.2 Many Prokaryotic Genes Are Regulated in Operons 30. ANS: A PTS: 1 REF: Page TOP: Concept 11.2 Many Prokaryotic Genes Are Regulated in Operons 31. ANS: A PTS: 1 REF: Page 215 TOP: Concept 11.2 Many Prokaryotic Genes Are Regulated in Operons 32. ANS: E PTS: 1 REF: Page 216 TOP: Concept 11.3 Eukaryotic Genes Are Regulated by Transcription Factors and DNA Changes

12 33. ANS: B PTS: 1 REF: Page TOP: Concept 11.3 Eukaryotic Genes Are Regulated by Transcription Factors and DNA Changes 34. ANS: B PTS: 1 REF: Page TOP: Concept 11.3 Eukaryotic Genes Are Regulated by Transcription Factors and DNA Changes SKL: 3. Applying 35. ANS: E PTS: 1 REF: Page TOP: Concept 11.3 Eukaryotic Genes Are Regulated by Transcription Factors and DNA Changes 36. ANS: E PTS: 1 REF: Page TOP: Concept 11.3 Eukaryotic Genes Are Regulated by Transcription Factors and DNA Changes 37. ANS: C PTS: 1 REF: Page TOP: Concept 11.3 Eukaryotic Genes Are Regulated by Transcription Factors and DNA Changes 38. ANS: E PTS: 1 REF: Page TOP: Concept 11.4 Eukaryotic Gene Expression Can Be Regulated after Transcription 39. ANS: C PTS: 1 REF: Page 223 TOP: Concept 11.4 Eukaryotic Gene Expression Can Be Regulated after Transcription 40. ANS: A PTS: 1 REF: Page 224 TOP: Concept 11.4 Eukaryotic Gene Expression Can Be Regulated after Transcription SKL: 3. Applying 41. ANS: C PTS: 1 REF: Page 264 TOP: Concept 14.1 Development Involves Distinct but Overlapping Processes 42. ANS: A PTS: 1 REF: Page 264 TOP: Concept 14.1 Development Involves Distinct but Overlapping Processes 43. ANS: C PTS: 1 REF: Page TOP: Concept 14.1 Development Involves Distinct but Overlapping Processes 44. ANS: D PTS: 1 REF: Page TOP: Concept 14.1 Development Involves Distinct but Overlapping Processes 45. ANS: E PTS: 1 REF: Page TOP: Concept 14.1 Development Involves Distinct but Overlapping Processes 46. ANS: E PTS: 1 REF: Page 269 TOP: Concept 14.2 Changes in Gene Expression Underlie Cell Differentiation in Development 47. ANS: B PTS: 1 REF: Page TOP: Concept 14.2 Changes in Gene Expression Underlie Cell Differentiation in Development 48. ANS: D PTS: 1 REF: Page 273

13 49. ANS: A PTS: 1 REF: Page ANS: C PTS: 1 REF: Page ANS: C PTS: 1 REF: Page ANS: A PTS: 1 REF: Page ANS: B PTS: 1 REF: Page ANS: D PTS: 1 REF: Page ANS: B PTS: 1 REF: Page 278 TOP: Concept 14.4 Gene Expression Pathways Underlie the Evolution of Development 56. ANS: D PTS: 1 REF: Page 279 TOP: Concept 14.4 Gene Expression Pathways Underlie the Evolution of Development 57. ANS: E PTS: 1 REF: Page 280 TOP: Concept 14.4 Gene Expression Pathways Underlie the Evolution of Development 58. ANS: D PTS: 1 REF: Page TOP: Concept 14.5 Developmental Genes Contribute to Species Evolution but Also Pose Constraints 59. ANS: C PTS: 1 REF: Page 282 TOP: Concept 14.5 Developmental Genes Contribute to Species Evolution but Also Pose Constraints 60. ANS: E PTS: 1 REF: Page TOP: Concept 14.5 Developmental Genes Contribute to Species Evolution but Also Pose Constraints