AP Biology chapter 20 Practice Questions 1) Plasmids are important in biotechnology because they are A) a vehicle for the insertion of recombinant DNA into bacteria. B) recognition sites on recombinant DNA strands. C) surfaces for protein synthesis in eukaryotic recombinants. D) surfaces for respiratory processes in bacteria. E) proviruses incorporated into the host DNA. 2) 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 3) What is the genetic function of restriction enzyme? A) adds new nucleotides to the growing strand of DNA B) joins nucleotides during replication C) joins nucleotides during transcription D) cleaves nucleic acids at specific sites E) repairs breaks in sugar-phosphate backbones 4) What is a cloning vector? A) the enzyme that cuts DNA into restriction fragments B) a DNA probe used to locate a particular gene in the genome C) an agent, such as a plasmid, used to transfer DNA from an in vitro solution into a living cell D) the laboratory apparatus used to clone genes 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 5) From the list above, which of the following is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? A) I, II, IV, III, V D) III, IV, V, I, II B) II, III, V, IV, I E) IV, V, I, II, III C) III, II, IV, V, I 6) All of the following statements about probes are true except: A) They are single-stranded segments of DNA or RNA. B) Shorter probes adhere to more fragments than do longer probes. C) The probe must be labeled with a radioactive isotope or fluorescent tab. D) They must be produced with the same restriction enzyme as the fragments. E) In many cases, a probe from one organism can be used to locate a homologous DNA segment in another organism. 7) The principal problem with inserting an unmodified mammalian gene into the bacterial chromosome, and then getting that gene expressed, 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. D) bacterial RNA polymerase cannot make RNA complementary to mammalian DNA. E) bacterial DNA is not found in a membraneenclosed nucleus and is therefore incompatible with mammalian DNA. 8) Yeast cells are frequently used as hosts for cloning because A) they are easy to grow. B) they have multiple restriction sites. C) they have plasmids. D) A and B are correct. E) A and C are correct. 9) produces multiple identical copies of a gene for basic research or for large-scale production of a gene product A. B. C. D. E. restriction enzymes gene cloning DNA ligase gel electrophoresis reverse transcriptase 10) separates molecules by movement due to size and electrical charge A. B. C. D. E. restriction enzymes gene cloning DNA ligase gel electrophoresis reverse transcriptase 11) Which enzyme permanently seals together DNA fragments that have complementary sticky ends? A. B. C. D. E. restriction enzyme DNA ligase reverse transcriptase RNA polymerase DNA polymerase 12) Which enzyme is used to make multiple copies of genes in the polymerase chain reaction (PCR)? A. B. C. D. E. restriction enzyme DNA ligase reverse transcriptase RNA polymerase DNA polymerase 13) Which enzyme cuts DNA molecules at specific locations? A. B. C. D. E. restriction enzyme DNA ligase reverse transcriptase RNA polymerase DNA polymerase 14) The Southern blotting procedure enables the detection and analysis of DNA sequences. This means that A) the existence of specific sequences can be determined. B) the number of sequences can be determined. C) the size of restriction fragments that contain the sequence can be determined. D) the DNA of individuals and species can be compared. E) all of the above are possible using the Southern blotting procedure. 15) Surprisingly, the human genome contains fewer genes than expected. How, then, is the human genome more complex than that of other organisms? A) RNA transcripts of human genes are more likely to experience alternative splicing. B) Post-translational processing adds diversity to the resulting polypeptides. C) Polypeptide domains are combined in a variety of ways. D) Different combinations of exons are used. E) All of the above are correct. 16) 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) has its greatest chance of success with bone marrow cells. E) is a widely accepted procedure. 17) Genetically engineered plants A) are more difficult to engineer than animals. B) include a transgenic rice plant that could help prevent vitamin A deficiency. C) are being rapidly developed, but traditional plant breeding programs are still the method used to develop new plants. D) are able to fix nitrogen themselves. E) are all monocots. 18) Which of the following tools of recombinant DNA technology is incorrectly paired with its use? A) restriction enzyme¹production of RFLPs B) DNA ligase¹enzyme that cuts DNA, creating the sticky ends of restriction fragments C) DNA polymerase¹used in a polymerase chain reaction to amplify sections of DNA D) reverse transcriptase¹production of cDNA from mRNA E) electrophoresis¹DNA sequencing 19) 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. 20) 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 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 hybridization 21) Expression of a cloned eukaryotic gene in a prokaryotic cell involves many difficulties. 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.