DNA and Gene Expression (chaps 12-15)

Transcription

1 Name: Class: _ Date: _ DNA and Gene Expression (chaps 12-15) Multiple Choice Identify the choice that best completes the statement or answers the question. 1 Who first confirmed that the replication of DNA was semiconservative? A. Watson, Crick, and Wilkins B. Avery and Griffith C. Chargaff and Hershey D. Watson and Crick E. Meselson and Stahl 2 Which of the following types of processing does eukaryotic mrna undergo before it becomes functional? A. polyadenylation B. capping C. splicing D. removal of introns E. All of these. 3 In the experiments of Griffith, the conversion of nonlethal R-strain bacteria to lethal S-strain bacteria: A. was an example of conjugation. B. was the result of genetic mutation. C. was an example of the genetic exchange known as transformation. D. supported the case for proteins as the genetic material. E. could not be reproduced by other researchers. 4 A new operon is discovered in a bacterium. The control of this operon is affected by a protein that is made by another gene, and is made in an active form that binds to the DNA near the operon to prevent transcription. This is an example of control. A. negative B. activational C. positive D. repressing E. inducing 1

2 Name: Figure 12-2 Use the figure to answer the corresponding question(s). 5 Refer to Figure The segments labeled F are responsible for: A. unwinding the DNA double helix. B. initiating DNA synthesis. C. synthesizing the leading strand. D. forming the replication fork. E. linking short DNA segments. 6 Refer to Figure The correct designation for the DNA strand labeled C is: A. polymerase. B. 3!. C. the leading strand. D. Okazaki fragments. E. None of these. 7 Refer to Figure The structures represented by the letter E are called: A. replication forks. B. leading fragments C. DNA polymerases. D. nucleosomes. E. Okazaki fragments. 8 Refer to Figure The enzyme represented by the letter D is responsible for: A. forming the replication fork. B. synthesizing the leading strand. C. forming nucleosomes. D. linking short DNA segments. E. unwinding the DNA double helix. 2

3 Name: 9 Retroviruses or RNA tumor viruses use to make DNA. A. reverse transcriptase B. DNA polymerase C. DNA-dependent RNA polymerase D. RNA polymerase E. primase 10 Regulation of gene expression can be accomplished by controlling: A. the rate of translation of mrna. B. the activity of a protein product. C. the amount of mrna that is available. D. the rate of mrna degradation. E. All of these. 11 The gene that codes for the repressor protein of the E. coli lactose operon is: A. downstream from the operator. B. constitutive. C. turned off most of the time. D. downstream from the promoter region. E. located between the operator and the promoter. 12 Primase is the enzyme responsible for: A. forming a replication fork in the DNA double helix. B. making short strands of RNA at the site of replication initiation. C. introducing nicks into the DNA double strand in order to prevent the formation of knots. D. hydrolyzing ATP to facilitate DNA unwinding. E. unwinding the DNA double strand to allow DNA polymerase access to the template DNA. 13 A is required to transfer genes from one organism to another. A. PCR device B. genetic probe C. reverse transcriptase D. vector E. transport molecule 14 Repressible genes are usually actively transcribed when: A. quantities of precursor materials are high. B. tryptophan accumulates in the cell. C. there is no other substrate that can be used by the cell. D. repressor molecules bind to the promoter. E. the supply of the end product formed by the enzymes encoded by these genes is low. 3

4 Name: 15 Two chains of DNA must run in direction(s) and must be if they are to bond with each other. A. parallel; uncomplementary B. the same; uncomplementary C. opposite; uncomplementary D. parallel; complementary E. antiparallel; complementary Figure 13-2 Use the figure to answer the corresponding question(s). 16 Refer to Figure The portion of the molecule labeled 5 is: A. a single-stranded region. B. a double-stranded region. C. the attached amino acid. D. the anticodon. E. the codon. 4

5 Name: 17 Which of the following nucleotide sequences represents the complement to the DNA strand 5! " AGATCCG- 3!? A. 3! " CTCGAAT- 5! B. 5! " CTCGAAT- 3! C. 5! " AGATCCG- 3! D. 3! " TCTAGGC- 5! E. 3! " AGATCCG- 5! 18 Interrupted coding sequences include long sequences of bases that do not code for amino acids. These noncoding sequences, called, are found in cells. A. introns; prokaryotic B. exons; prokaryotic C. exons; eukaryotic D. introns; eukaryotic E. None of these. 19 Initiation of transcription requires: A. Okazaki fragments. B. a promoter sequence. C. DNA polymerase. D. an RNA primer. E. a DNA primer. 20 The bacteriophages used in Alfred Hershey's and Martha Chase's experiments showed that: A. proteins were responsible for the production of new viruses within the bacteria. B. DNA and protein were injected into bacteria. C. DNA was injected into bacteria. D. proteins were injected into bacteria. E. DNA remained on the outer coat of bacteria. 21 How does the lactose repressor block transcription of the lactose operon? A. by slowing the uptake of lactose into the cell B. by binding allosterically to the appropriate genes C. by "turning off" the appropriate genes in the intron D. by regulating the activity of the enzymes that the operon codes for E. by binding to the operator 22 The chain termination method is used in: A. Southern blotting. B. DNA ligation. C. gel electrophoresis. D. polymerase chain reaction. E. DNA sequencing. 5

6 Name: 23 Bacterial gene regulation occurs mainly at the level. A. posttranslational B. feedback inhibition C. translational D. posttranscriptional E. transcriptional 24 The trna: A. must have an attachment site for the amino acid. B. must have an anticodon. C. must be recognized by ribosomes. D. must be recognized by a specific aminoacyl-trna synthetase that adds the correct amino acid. E. All of these. 25, the ends of eukaryotic chromosomes, shorten with every cell replication event. A. Telomeres B. Kinetochores C. Primosomes D. Centromeres E. Nucleosomes 26 The main reason scientists thought that proteins, rather than DNA, were the carriers of genetic material in the cell was: A. their abundance within the cell. B. their presence within the nucleus. C. the large number of possible amino acid combinations. D. their ability to be exported from the cell. E. their ability to self replicate within the cytoplasm. 27 Substitution of one base pair for another can result in a mutation that results in the conversion of an amino acid specifying codon to a termination codon. A. nonsense B. chromosomal C. frameshift D. missense E. None of these. 28 An inducible operon is usually controlled by: A. an active repressor that keeps it in the "off" state. B. being active at all times. C. allolactose. D. being turned "off," usually by the end product of the pathway. E. an inducer molecule that keeps it in the "off" state. 6

7 Name: 29 Frameshift mutations result from: A. the substitution of more than one base pair. B. the substitution of a stop codon for an amino acid-specifying codon. C. the substitution of one base pair for another. D. the insertion or deletion of one or two base pairs. E. the substitution of a start codon for an amino acid codon. 30 Which of the following bits of information can be inferred from the ratio of different-colored fluorescent dyes in a microarray? A. identification of disease-causing proteins B. comparison of drug activity C. identification of disease-causing genes D. patterns of gene expression E. All of these. 31 The codon is found in the: A. template strand of DNA. B. trna. C. nontemplate strand of DNA. D. rrna. E. mrna. 32 Which of the following statements about DNA is false? A. DNA is double-stranded rather than single-stranded. B. DNA contains the sugar deoxyribose. C. DNA contains thymine instead of uracil. D. DNA is only found in eukaryotic cells. E. DNA is capable of forming many different sequences. 33 Feedback inhibition of the first enzyme of a pathway by the end product of the pathway is an example of: A. posttranslational control. B. transcriptional control. C. repression. D. inhibiting control. E. translational control. 34 The first experimenters to use Griffith's transformation assay to identify the genetic material were: A. Avery, MacLeod, and McCarty. B. Hershey and Chase. C. Meselson and Stahl. D. Franklin and Wilkins. E. Watson and Crick. 7

8 Name: 35 used x-ray diffraction to provide images of DNA. A. Frederick Griffith B. Francis Crick C. Rosalind Franklin D. James Watson E. Erwin Chargaff 36 Uracil forms a complementary pair with in RNA and in DNA. A. thymine; thymine B. adenine; thymine C. uracil; adenine D. adenine; adenine E. adenine; uracil 37 The 3! end of eukaryotic pre-mrnas are changed by: A. adding a "cap." B. removing the last phosphate group. C. phosphorylation of the mrna molecule. D. copying the last few bases so that it can form a duplex structure. E. cutting and adding 100"250 adenine nucleotides. 38 The enzyme peptidyl transferase, which catalyzes the transfer of the polypeptide chain attached to the trna in the site to the aminoacyl-trna in the site, is thought to be a(n) molecule and not a protein. A. P; A; sugar B. P; A; rrna C. A; P; mrna D. P; A; trna E. A; P; rdna 8

9 Name: Figure 15-1 Use the figure to answer the corresponding question(s). 39 Refer to Figure The use of antibiotic medium at the end of this process: A. prevents contamination of the medium. B. selects for plasmids containing particular DNA fragments. C. selects for bacteria containing plasmids. D. selects for bacteria lacking plasmids. E. selects against plasmids containing human DNA fragments. 40 What process or enzyme was used for Step 1 in Figure 15-1? A. a bacteriophage B. a reverse transcriptase C. a restriction enzyme D. a DNA ligase E. PCR 9

10 Name: 41 If a protein-coding gene is identified, its function can be studied by using RNA interference to. A. turn the gene off B. turn the gene on C. produce a RFLP D. induce a mutation E. produce an EST 42 A cell may meet the need for large quantities of a specific protein by: A. increasing the half-life of the mrna that specifies the protein. B. having multiple copies of the gene that codes for that protein. C. continuously synthesizing the mrna molecule that specifies that protein. D. All of these. E. None of these. 43 DNA sequences that are methylated by a cell are usually genes that: A. are constitutive. B. are inactive. C. are repressed. D. are actively expressed. E. have been replicated 44 The information carried by DNA is incorporated in a code specified by the: A. size of a particular chromosome. B. number of bases in a DNA strand. C. specific nucleotide sequence of the DNA molecule. D. phosphodiester bonds of the DNA strand. E. number of separate strands of DNA. 45 The total DNA in a cell is referred to as the: A. library. B. genome. C. chromosomal DNA. D. cdna. E. None of these. 46 In all organisms, the AUG codon codes for: A. a termination trna molecule. B. the termination of chain elongation. C. the initiation of translation. D. the amino acid valine. E. the termination of transcription. 10

11 Name: 47 One of the mrna codons specifying the amino acid leucine is 5!-CUA-3!. Its corresponding anticodon is: A. 5!-GAU-3!. B. 3!-GAT-5!. C. 3!-AUC-5!. D. 3!-GAU-5!. E. 5!-GAT-3!. 48 RNA differs from DNA in all the following except: A. RNA contains uracil and DNA contains thymine. B. RNA is single stranded and DNA is double stranded. C. RNA contains ribose and DNA contains deoxyribose. D. RNA is a larger molecule than DNA. E. None of the above. 49 Hydrogen bonds can form between guanine and, and between adenine and. A. cytosine; thymine B. thymine; cytosine C. sugar; phosphate D. adenine; guanine E. phosphate; sugar 50 The ends of eukaryotic chromosomes can be lengthened by: A. primase. B. DNA polymerase. C. reverse transcriptase. D. apoptosis. E. telomerase. 51 Which of the following adds new nucleotides to a growing DNA chain? A. DNA polymerase B. DNA helicase C. RNA polymerase D. RNA primer E. primase 52 Increasing the stability of a particular mrna the expression of that gene. A. decreases B. does not affect C. increases D. eliminates E. None of these. 11

12 Name: 53 In eukaryotes, some DNA sequences act as introns in some cells and as exons in other cells. This is an example of. A. gene processing B. gene amplification C. gene repression D. differential mrna processing E. mrna splicing 54 Translational controls regulate: A. the uptake of nucleic acids into the cell. B. the attachment of phosphate groups to polypeptides. C. the rate at which an mrna molecule is synthesized. D. the rate at which an mrna molecule is translated. E. the activity of a protein end-product that is produced. 55 Chargaff determined that DNA from any source contains about the same amount of guanine as. A. cytosine B. adenine C. thymine D. guanine E. uracil 56 In replication, once the DNA strands have been separated, reformation of the double helix is prevented by: A. GTP. B. ATP. C. DNA polymerases. D. single-strand binding proteins. E. DNA helicase enzyme. 57 A mutation that replaces one amino acid in a protein with another is called a mutation. A. neutral B. recombinant C. nonsense D. missense E. frameshift 12

13 Name: Figure 12-1 Use the figure to answer the corresponding question(s). 58 The portion of the molecule in box 5 of Figure 12-1 is: A. a protein. B. a nucleotide. C. a pyrimidine. D. a hydrogen bond. E. a phosphate. 59 The portion of the molecule in box 3 of Figure 12-1 is: A. a nucleotide. B. a protein. C. a sugar. D. a pyrimidine. E. a purine. 13

14 Name: 60 Which of the following serves as an "adapter" in protein synthesis and bridges the gap between mrna and proteins? A. rrna B. cdna C. promoter sequences D. trna E. DNA 61 The focus of gene regulation in multicellular organisms is on: A. the specificity of products in different tissues. B. economizing resources at all levels. C. rapid turnover of RNA molecules. D. operons. E. All of these. 62 determined the structure of the molecule DNA. A. Franklin B. Franklin and Crick C. Watson and Crick D. Crick and Wilkins E. Watson, Crick, and Wilkins 63 To avoid the introduction of introns into the vector, a copy of mature mrna is made, using the enzyme. A. cdna; DNA ligase B. cdna; reverse transcriptase C. sdna; reverse transcriptase D. sdna; RNA polymerase E. cdna; DNA polymerase 64 What prevents knot formation in replicating DNA? A. protosomes B. chromatin C. scaffolding proteins D. topoisomerases E. histones 65 A chromosome library is a collection of all of the DNA: A. that would be found in the chromosomes of a typical cell of a particular organism. B. that occurs in one species. C. that codes for functional enzymes in a chromosome of a particular organism. D. contained in one chromosome. E. in a recombinant gene. 14

15 Name: 66 Cancer cells differ from noncancerous cells in that: A. they have the ability to resist apoptosis. B. they are virtually immortal. C. they can maintain telomere length as they divide. D. they have elevated levels of telomerase. E. All of these. 67 Genes that encode proteins that are always needed are called: A. constitutive genes. B. operons. C. repressible genes. D. inducible genes. E. promoter genes. 68 An mrna "5! cap": A. decreases the half-life of the mrna. B. facilitates binding of ribosomes. C. marks the mrna for degradation. D. prevents translation. E. protects newly synthesized mrna from degradation. 69 is a technique that can be used to separate DNA molecules on the basis of their size. A. PCR B. Selective sorting C. Separation gradient D. Cloning E. Electrophoresis 70 During protein synthesis, ribosomes: A. attach to the mrna molecule and travel along its length. B. translate mrna into DNA. C. transcribe mrna to trna. D. translate mrna into trna. E. attach to the DNA molecule and travel along its length to produce an mrna molecule. 71 Which of the following cause the unwinding of the DNA double helix? A. RNA polymerase B. DNA polymerase C. DNA helicase D. RNA primer E. primosome 15

16 Name: 72 Transformation is a process whereby: A. bacteria are transferred into plasmid cells. B. plasmids are transferred into bacterial cells. C. viruses are transferred into bacterial cells. D. plasmids are transferred into viral cells. E. bacteria are transferred into viral cells. 73 The DNA strand that is replicated smoothly and continuously is called the: A. lagging strand. B. first strand. C. leading strand. D. primary strand. E. alpha strand. Figure 13-3 Use the figure to answer the corresponding question(s). 74 The process illustrated in Figure 13-3 is: A. protein synthesis. B. transcription. C. a frame shift mutation. D. DNA synthesis. E. translation. 75 A gene can now be defined as: A. a DNA sequence that carries information to produce a specific RNA or protein product. B. a DNA or RNA sequence that carries information to produce a single polypeptide. C. a DNA nucleotide sequence that carries information to produce a specific polypeptide. D. a DNA or RNA sequence that carries information to produce a specific polypeptide. E. a DNA nucleotide sequence that carries information to produce an enzyme. 16

17 Name: 76 PCR: A. has applications for archaeology and crime scene analysis. B. is used to amplify tiny quantities of DNA in vitro. C. can only be carried out if DNA polymerase is heat resistant. D. replicates specific DNA sequences. E. All of these. 17

18 Name: Essay Describe the biochemical composition, structure, and replication of DNA. Discuss what drives the adding on nucleotides. 2. Describe the steps of protein synthesis, beginning with the attachment of a messenger RNA molecule to the small subunit of a ribosome and ending generalized with the release of the polypeptide from the ribosome. Include in your answer a discussion of how the different types of RNA function in this process. 3. Describe the operon hypothesis and discuss how it explains the control of messenger RNA production and the regulation of protein synthesis in bacterial cells. 4. The diagram below shows a segment of DNA with a total length of 4,900 base pairs. The arrows indicate reaction sites for two restriction enzymes (enzyme X and enzyme Y). 1. Explain how the principles of gel electrophoresis allow for the separation of DNA fragments. 2. Describe the results you would expect from the electrophoresis separation of fragments from the following treatments of the DNA segment above. Assume that the digestions occurred under appropriate conditions and went to completion. 1. DNA digested with only enzyme X 2. DNA digested with only enzyme Y 3. DNA digested with enzyme X and enzyme Y combined 4. Undigested DNA 3. Explain both of the following. 1. The mechanism of action of restriction enzymes. 2. The different results you would expect if a mutation occurred at the recognition site for enzyme Y. 18

19 DNA and Gene Expression (chaps 12-15) Answer Section MULTIPLE CHOICE 1 ANS: E 2 ANS: E 3 ANS: C 4 ANS: A 5 ANS: B 6 ANS: E 7 ANS: E 8 ANS: D 9 ANS: A 10 ANS: E 11 ANS: B 12 ANS: B 13 ANS: D 14 ANS: E 15 ANS: E 16 ANS: C 17 ANS: D 18 ANS: D 19 ANS: B 20 ANS: C 21 ANS: E 22 ANS: E 23 ANS: E 24 ANS: E 25 ANS: A 26 ANS: C 27 ANS: A 28 ANS: A 1

20 29 ANS: D 30 ANS: E 31 ANS: E 32 ANS: D 33 ANS: A 34 ANS: A 35 ANS: C 36 ANS: D 37 ANS: E 38 ANS: B 39 ANS: C 40 ANS: C 41 ANS: A 42 ANS: D 43 ANS: B 44 ANS: C 45 ANS: B 46 ANS: C 47 ANS: D 48 ANS: D 49 ANS: A 50 ANS: E 51 ANS: A 52 ANS: C 53 ANS: D 54 ANS: D 55 ANS: A 56 ANS: D 57 ANS: D 58 ANS: E 59 ANS: E 60 ANS: D 2

21 61 ANS: A 62 ANS: C 63 ANS: B 64 ANS: D 65 ANS: D 66 ANS: E 67 ANS: A 68 ANS: E 69 ANS: E 70 ANS: A 71 ANS: C 72 ANS: B 73 ANS: C 74 ANS: B 75 ANS: A 76 ANS: E ESSAY 77 ANS: answers will vary 3