BIO 111 Ch 20

B

1) Which of the following tools of recombinant DNA technology is incorrectly paired with its use? A) restriction enzyme-production of RFLPs B) DNA ligase-enzyme that cuts DNA, creating the sticky ends of restriction fragments C) DNA polymerase-used in a polymerase chain reaction to amplify sections of DNA D) reverse transcriptase-production of cDNA from mRNA E) electrophoresis-separation of DNA fragments

C

10) A principal problem with inserting an unmodified mammalian gene into a bacterial plasmid, and then getting that gene expressed in bacteria, is that A) prokaryotes use a different genetic code from that of eukaryotes. B) bacteria translate polycistronic messages only. C) bacteria cannot remove eukaryotic introns. 3 D) bacterial RNA polymerase cannot make RNA complementary to mammalian DNA. E) bacterial DNA is not found in a membrane-bounded nucleus and is therefore incompatible with mammalian DNA.

C

11) A gene that contains introns can be made shorter (but remain functional) for genetic engineering purposes by using A) RNA polymerase to transcribe the gene. B) a restriction enzyme to cut the gene into shorter pieces. C) reverse transcriptase to reconstruct the gene from its mRNA. D) DNA polymerase to reconstruct the gene from its polypeptide product. E) DNA ligase to put together fragments of the DNA that codes for a particular polypeptide.

D

12) Why are yeast cells frequently used as hosts for cloning? A) they easily form colonies B) they can remove exons from mRNA. C) they do not have plasmids. D) they are eukaryotic cells E) only yeast cells allow the gene to be cloned

A

13) The DNA fragments making up a genomic library are generally contained in A) recombinant plasmids of bacteria. B) recombinant viral RNA. C) individual wells. D) DNA-RNA hybrids E) radioactive eukaryotic cells

C

14) How does a genomic library differ from a cDNA library? A) A genomic library contains only noncoding sequences, whereas a cDNA library contains only coding sequences. B) A genomic library varies, dependent on the cell type used to make it, whereas the content of a cDNA library does not. 4 C) A genomic library can be made using a restriction enzyme and DNA ligase only, whereas a cDNA library requires both of these as well as reverse transcriptase and DNA polymerase. D) The genomic library can be replicated but not transcribed. E) The genomic library contains only the genes that can be expressed in the cell.

E

15) Yeast artificial chromosomes contain which of the following elements? A) centromere only B) telomeres only C) origin of replication only D) centromeres and telomeres only E) centromere, telomeres, and an origin of replication

A

16) Which of the following best describes the complete sequence of steps occurring during every cycle of PCR? 1. The primers hybridize to the target DNA. 2. The mixture is heated to a high temperature to denature the double stranded target DNA. 3. Fresh DNA polymerase is added. 4. DNA polymerase extends the primers to make a copy of the target DNA. A) 2, 1, 4 B) 1, 3, 2, 4 C) 3, 4, 1, 2 D) 3, 4, 2 E) 2, 3, 4

E

17) A researcher needs to clone a sequence of part of a eukaryotic genome in order to express the sequence and to modify the polypeptide product. She would be able to satisfy these requirements by using which of the following vectors? A) a bacterial plasmid B) BAC to accommodate the size of the sequence C) a modified bacteriophage D) a human chromosome E) a YAC with appropriate cellular enzymes

C

18) A student wishes to clone a sequence of DNA of ~200 kb. Which vector would be appropriate? A) a plasmid B) a typical bacteriophage C) a BAC D) a plant virus E) a large polypeptide

A

19) The first cell whose entire genome was sequenced was which of the following? A) H. influenzae in 1995 B) H. sapiens in 2001 C) rice in 1955 D) tobacco mosaic virus E) HIV in 1998

C

2) Assume that you are trying to insert a gene into a plasmid. Someone gives you a preparation of genomic DNA that has been cut with restriction enzyme X. The gene you wish to insert has sites on both ends for cutting by restriction enzyme Y. You have a plasmid with a single site for Y, but not for X. Your strategy should be to A) insert the fragments cut with X directly into the plasmid without cutting the plasmid. B) cut the plasmid with restriction enzyme X and insert the fragments cut with Y into the plasmid. C) cut the DNA again with restriction enzyme Y and insert these fragments into the plasmid cut with the same enzyme. D) cut the plasmid twice with restriction enzyme Y and ligate the two fragments onto the ends of the DNA fragments cut with restriction enzyme X. E) cut the plasmid with enzyme X and then insert the gene into the plasmid.

B

2) Which of the following would not be true of cDNA produced using human brain tissue as the starting material? A) It could be amplified by the polymerase chain reaction. B) It could be used to create a complete genomic library. C) It is produced from mRNA using reverse transcriptase. D) It could be used as a probe to detect genes expressed in the brain. E) It lacks the introns of the human genes.

D

20) Sequencing an entire genome, such as that of C. elegans, a nematode, is most important because A) it allows researchers to use the sequence to build a "better" nematode, resistant to disease. B) it allows research on a group of organisms we do not usually care much about. C) the nematode is a good animal model for trying out cures for viral illness. D) a sequence that is found to have a particular function in the nematode is likely to have a closely related function in vertebrates. E) a sequence that is found to have no introns in the nematode genome is likely to have acquired the introns from higher organisms.

B

21) To introduce a particular piece of DNA into an animal cell, such as that of a mouse, you would find more probable success with which of the following methods? A) the shotgun approach B) electroporation followed by recombination C) introducing a plasmid into the cell D) infecting the mouse cell with a Ti plasmid E) transcription and translation

C

22) The major advantage of using artificial chromosomes such as YACs and BACs for cloning genes is that A) plasmids are unable to replicate in cells. B) only one copy of a plasmid can be present in any given cell, whereas many copies of a YAC or BAC can coexist in a single cell. C) YACs and BACs can carry much larger DNA fragments than ordinary plasmids can. D) YACs and BACs can be used to express proteins encoded by inserted genes, but plasmids cannot. E) all of the above

B

23) Which of the following produces multiple identical copies of a gene for basic research or for large-scale production of a gene product? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

C

24) Which of the following seals the sticky ends of restriction fragments to make recombinant DNA? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

E

25) Which of the following is used to make complementary DNA (cDNA) from RNA? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

A

26) Which of the following cuts DNA molecules at specific locations? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

D

27) Which of the following separates molecules by movement due to size and electrical charge? A) restriction enzymes B) gene cloning C) DNA ligase D) gel electrophoresis E) reverse transcriptase

C

28) Restriction fragments of DNA are typically separated from one another by which process? A) filtering B) centrifugation C) gel electrophoresis D) PCR E) electron microscopy

E

29) In order to identify a specific restriction fragment using a probe, what must be done? A) The fragments must be separated by electrophoresis. B) The fragments must be treated with heat or chemicals to separate the strands of the double helix. C) The probe must be hybridized with the fragment. D) Only A and B are correct. E) A, B, and C are correct.

C

3) Plants are more readily manipulated by genetic engineering than are animals because A) plant genes do not contain introns. B) more vectors are available for transferring recombinant DNA into plant cells. C) a somatic plant cell can often give rise to a complete plant. D) genes can be inserted into plant cells by microinjection. E) plant cells have larger nuclei.

D

3) What is the enzymatic function of restriction enzymes? A) to add new nucleotides to the growing strand of DNA B) to join nucleotides during replication C) to join nucleotides during transcription 1 D) to cleave nucleic acids at specific sites E) to repair breaks in sugar-phosphate backbones

A

30) Which of the following modifications is least likely to alter the rate at which a DNA fragment moves through a gel during electrophoresis? A) altering the nucleotide sequence of the DNA fragment B) methylating the cytosine bases within the DNA fragment C) increasing the length of the DNA fragment D) decreasing the length of the DNA fragment E) neutralizing the negative charges within the DNA fragment

A

31) DNA fragments from a gel are transferred to a nitrocellulose paper during the procedure called Southern blotting. What is the purpose of transferring the DNA from a gel to a nitrocellulose paper? A) to attach the DNA fragments to a permanent substrate B) to separate the two complementary DNA strands C) to transfer only the DNA that is of interest D) to prepare the DNA for digestion with restriction enzymes E) to separate out the PCRs

A

32) RFLP analysis can be used to distinguish between alleles based on differences in which of the following? A) restriction enzyme recognition sites between the alleles B) the amount of DNA amplified from the alleles during PCR C) the ability of the alleles to be replicated in bacterial cells D) the proteins expressed from the alleles E) the ability of nucleic acid probes to hybridize to the alleles

B

33) The segment of DNA shown in Figure 20.2 has restriction sites I and II, which create restriction fragments A, B, and C. Which of the gels produced by electrophoresis shown below best represents the separation and identity of these fragments? A) 9 B) C) D) E)

C

34) Which of the following procedures would produce RFLPs? A) incubating a mixture of single-stranded DNA from two closely related species B) incubating DNA nucleotides with DNA polymerase C) incubating DNA with restriction enzymes D) incubating RNA with DNA nucleotides and reverse transcriptase E) incubating DNA fragments with "sticky ends" with ligase

B

35) Dideoxyribonucleotide chain-termination is a method of A) cloning DNA. B) sequencing DNA. C) digesting DNA. D) synthesizing DNA. E) separating DNA fragments.

C

36) DNA microarrays have made a huge impact on genomic studies because they A) can be used to eliminate the function of any gene in the genome. B) can be used to introduce entire genomes into bacterial cells. C) allow the expression of many or even all of the genes in the genome to be compared at once. D) allow physical maps of the genome to be assembled in a very short time. E) dramatically enhance the efficiency of restriction enzymes.

A

37) Which was developed by a British researcher and causes DNA sequences to be transferred to a membrane and identified with a probe? A) Southern blotting B) Northern blotting C) Western blotting D) Eastern blotting E) RT-PCR

C

38) Which describes the transfer of polypeptide sequences to a membrane to analyze gene expression? A) Southern blotting B) Northern blotting C) Western blotting D) Eastern blotting E) RT-PCR

E

39) Which uses reverse transcriptase to make cDNA followed by amplification? A) Southern blotting B) Northern blotting C) Western blotting D) Eastern blotting E) RT-PCR

B

4) A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). The researcher would like to compare a specific region of the DNA from the sample with DNA from living birds. Which of the following would be most useful for increasing the amount of dodo DNA available for testing? A) RFLP analysis B) polymerase chain reaction (PCR) C) electroporation D) gel electrophoresis E) Southern blotting

A

4) How does a bacterial cell protect its own DNA from restriction enzymes? A) adding methyl groups to adenines and cytosines B) using DNA ligase to seal the bacterial DNA into a closed circle C) adding histones to protect the double-stranded DNA D) forming "sticky ends" of bacterial DNA to prevent the enzyme from attaching E) reinforcing the bacterial DNA structure with covalent phosphodiester bonds

B

40) RNAi methodology uses double-stranded pieces of RNA to trigger a breakdown or blocking of mRNA. For which of the following might it more possibly be useful? A) to raise the rate of production of a needed digestive enzyme B) to decrease the production from a harmful gain-of-function mutated gene C) to destroy an unwanted allele in a homozygous individual D) to form a knockout organism that will not pass the deleted sequence to its progeny E) to raise the concentration of a desired protein

A

41) A researcher has used in vitro mutagenesis to mutate a cloned gene and then has reinserted this into a cell. In order to have the mutated sequence disable the function of the gene, what must then occur? A) recombination resulting in replacement of the wild type with the mutated gene B) use of a microarray to verify continued expression of the original gene C) replication of the cloned gene using a bacterial plasmid D) transcription of the cloned gene using a BAC E) attachment of the mutated gene to an existing mRNA to be translated

C

42) Which of the following techniques used to analyze gene function depends on the specificity of DNA base complementarity? A) Northern blotting B) use of RNAi C) in vitro mutagenesis D) in situ hybridization E) restriction fragment analysis

E

43) Which of the following is most closely identical to the formation of twins? A) cell cloning B) therapeutic cloning C) use of adult stem cells D) embryo transfer E) organismal cloning

D

44) In 1997, Dolly the sheep was cloned. Which of the following processes was used? A) use of mitochondrial DNA from adult female cells of another ewe B) replication and dedifferentiation of adult stem cells from sheep bone marrow C) separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe D) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate E) isolation of stem cells from a lamb embryo and production of a zygote equivalent

C

45) Which of the following problems with animal cloning might result in premature death of the clones? A) use of pluripotent instead of totipotent stem cells B) use of nuclear DNA as well as mtDNA C) abnormal regulation due to variant methylation D) the indefinite replication of totipotent stem cells E) abnormal immune function due to bone marrow dysfunction

B

46) Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning there is a wider divergence of opinion. Which of the following is a likely explanation? A) Use of adult stem cells is likely to produce more cell types than use of embryonic stem cells. B) Cloning to produce embryonic stem cells may lead to great medical benefits for many. C) Cloning to produce stem cells relies on a different initial procedure than reproductive cloning. D) A clone that lives until the blastocyst stage does not yet have human DNA. E) No embryos would be destroyed in the process of therapeutic cloning.

B

47) Which of the following is true of embryonic stem cells but not of adult stem cells? A) They can differentiate into many cell types. B) They make up the majority of cells of the tissue from which they are derived. C) They can continue to replicate for an indefinite period. D) They can provide enormous amounts of information about the process of gene regulation. E) One aim of using them is to provide cells for repair of diseased tissue.

A

48) A researcher is using adult stem cells and comparing them to other adult cells from the same tissue. Which of the following is a likely finding? A) The cells from the two sources exhibit different patterns of DNA methylation. B) Adult stem cells have more DNA nucleotides than their counterparts. C) The two kinds of cells have virtually identical gene expression patterns in microarrays. D) The non-stem cells have fewer repressed genes. E) The non-stem cells have lost the promoters for more genes.

B

49) Which of the following statements is consistent with the results? A) B is the child of A and C. B) C is the child of A and B. C) D is the child of B and C. D) A is the child of B and C. E) A is the child of C and D.

A

5) Expression of a cloned eukaryotic gene in a bacterial cell involves many challenges. The use of mRNA and reverse transcriptase is part of a strategy to solve the problem of A) post-transcriptional processing. B) electroporation. C) post-translational processing. D) nucleic acid hybridization. E) restriction fragment ligation.

C

5) What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? I. Transform bacteria with recombinant DNA molecule. II. Cut the plasmid DNA using restriction enzymes. III. Extract plasmid DNA from bacterial cells. IV. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. V. Use ligase to seal plasmid DNA to nonplasmid DNA. A) I, II, IV, III, V B) II, III, V, IV, I C) III, II, IV, V, I D) III, IV, V, I, II E) IV, V, I, II, III

B

50) Which of the following statements is most likely true? A) D is the child of A and C. B) D is the child of A and B. C) D is the child of B and C. D) A is the child of C and D. 14 E) B is the child of A and C.

D

51) Which of the following are probably siblings? A) A and B B) A and C C) A and D D) C and D E) B and D

D

52) Gene therapy A) has proven to be beneficial to HIV patients. B) involves replacement of a defective allele in sex cells. C) cannot be used to correct genetic disorders. D) had apparent success in treating disorders involving bone marrow cells. E) is a widely accepted procedure.

E

53) Genetic engineering is being used by the pharmaceutical industry. Which of the following is not currently one of the uses? A) production of human insulin B) production of human growth hormone C) production of tissue plasminogen activator D) genetic modification of plants to produce vaccines E) creation of products that will remove poisons from the human body

B

54) Genetically engineered plants A) are more difficult to engineer than animals. B) include a transgenic rice plant that can help prevent vitamin A deficiency. C) are being rapidly developed, but traditional plant breeding programs are still the only method used to develop new plants. D) are able to fix nitrogen themselves. E) are banned throughout the world.

A

55) Scientists developed a set of guidelines to address the safety of DNA technology. Which of the following is one of the adopted safety measures? A) Microorganisms used in recombinant DNA experiments are genetically crippled to ensure that they cannot survive outside of the laboratory. B) Genetically modified organisms are not allowed to be part of our food supply. C) Transgenic plants are engineered so that the plant genes cannot hybridize. D) Experiments involving HIV or other potentially dangerous viruses have been banned. E) Recombinant plasmids cannot be replicated.

C

56) One successful form of gene therapy has involved delivery of an allele for the enzyme adenosine deaminase (ADA) to bone marrow cells of a child with SCID, and delivery of these engineered cells back to the bone marrow of the affected child. What is one major reason for the success of this procedure as opposed to many other efforts at gene therapy? A) The engineered bone marrow cells from this patient can be used for any other SCID patient. B) The ADA introduced allele causes all other ADA-negative cells to die. C) The engineered cells, when reintroduced into the patient, find their way back to the bone marrow. D) No vector is required to introduce the allele into ADA-negative cells E) The immune system fails to recognize cells with the variant gene

D

57) Which of the following is one of the technical reasons why gene therapy is problematic? A) Most cells with an engineered gene do not produce gene product. B) Most cells with engineered genes overwhelm other cells in a tissue. C) Cells with transferred genes are unlikely to replicate. D) Transferred genes may not have appropriately controlled activity. E) mRNA from transferred genes cannot be translated.

D

58) Which of the following would be a reasonably efficient technique for confirming the diagnosis of CML? A) searching for the number of telomeric sequences on chromosome 22 B) looking for a Ph' chromosome in a peripheral blood smear C) enzyme assay for thymine kinase activity D) FISH study to determine the chromosomal location of all chromosome 22 q fragments E) identification of the disease phenotype in review of the patient's records

E

59) Why would Gleevec most probably cause remission of the disease? A) It reverses the chromosomal translocation. B) It eliminates the Ph' chromosome. C) It removes Ph'-containing progenitor cells. D) The drug inhibits the replication of the affected chromosome. E) The drug inhibits the specific thymine kinase receptor.

C

6) Bacteria containing recombinant plasmids are often identified by which process? A) examining the cells with an electron microscope B) using radioactive tracers to locate the plasmids C) exposing the bacteria to an antibiotic that kills cells lacking the resistant plasmid D) removing the DNA of all cells in a culture to see which cells have plasmids E) producing antibodies specific for each bacterium containing a recombinant plasmid

C

6) DNA technology has many medical applications. Which of the following is not done routinely at present? A) production of hormones for treating diabetes and dwarfism B) production of viral proteins for vaccines C) introduction of genetically engineered genes into human gametes D) prenatal identification of genetic disease genes E) genetic testing for carriers of harmful alleles

A

60) One possible use of transgenic plants is in the production of human proteins, such as vaccines. Which of the following is a possible hindrance that must be overcome? A) prevention of transmission of plant allergens to the vaccine recipients B) prevention of vaccine-containing plants being consumed by insects C) use of plant cells to translate non-plant derived mRNA D) inability of the human digestive system to accept plant-derived protein E) the need to cook all such plants before consuming them

C

61) As genetic technology makes testing for a wide variety of genotypes possible, which of the following is likely to be an increasingly troublesome issue? A) use of genotype information to provide positive identification of criminals B) using technology to identify genes that cause criminal behaviors C) the need to legislate for the protection of the privacy of genetic information D) discrimination against certain racial groups because of major genetic differences E) alteration of human phenotypes to prevent early disease

C

7) Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme? A) AAGG TTCC B) AGTC TCAG C) GGCC CCGG D) ACCA TGGT E) AAAA TTTT

E

8) Bacteria containing a plasmid into which the eukaryotic gene has integrated would grow in A) the nutrient broth only. B) the nutrient broth and the tetracycline broth only. C) the nutrient broth, the ampicillin broth, and the tetracycline broth. D) all four types of broth. E) the ampicillin broth and the nutrient broth.

D

8) In recombinant DNA methods, the term vector can refer to A) the enzyme that cuts DNA into restriction fragments. B) the sticky end of a DNA fragment. C) a RFLP marker. D) a plasmid used to transfer DNA into a living cell. E) a DNA probe used to identify a particular gene.

A

9) Bacteria that do not take up any plasmids would grow on which media? A) the nutrient broth only B) the nutrient broth and the tetracycline broth C) the nutrient broth and the ampicillin broth D) the tetracycline broth and the ampicillin broth E) all four broths

Answer: A cDNA library, made using mRNA from human lens cells, which would be expected to contain many copies of crystallin mRNAs

9) Imagine you want to study human crystallins, proteins present in the lens of the eye. To obtain a sufficient amount of the protein, you decide to clone the crystallin gene. Would you construct a genomic library or a cDNA library? What material would you use as a source of DNA or RNA?

D

A eukaryotic gene has "sticky ends" produced by the restriction endonuclease EcoRI. The gene is added to a mixture containing EcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline. The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene. This mixture is incubated for several hours, exposed to DNA ligase, and then added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth without antibiotics. 7) Bacteria that contain the plasmid, but not the eukaryotic gene, would grow A) in the nutrient broth plus ampicillin, but not in the broth containing tetracycline. B) only in the broth containing both antibiotics. C) in the broth containing tetracycline, but not in the broth containing ampicillin. D) in all four types of broth. E) in the nutrient broth without antibiotics only.

C

re 1) Which enzyme was used to produce the molecule in Figure 20.1? A) ligase B) transcriptase C) a restriction enzyme D) RNA polymerase E) DNA polymerase