Test Bank Microbiology Human Perspective 6th Edition by Nester Anderson Roberts

Test Bank Microbiology Human Perspective 6th Edition by Nester Anderson Roberts

Chapter 09
Biotechnology and Recombinant DNA

Multiple Choice Questions

1. Short tandem repeats (STRs)
A. are useful in identifying specific individuals
B. are important sites in vectors where foreign DNA can be integrated
C. are errors that can arise during DNA sequencing
D. are DNA fragments generated during PCR

2. Mitochondrial DNA (mtDNA) in humans
A. can be found in both parents
B. can be used to identify related people
C. can be isolated only from intact embryos
D. can be used to establish paternity

3. DNA molecules that contain pieces of DNA from two different sources are defined as
A. biotechnology.
B. gene cloning.
C. recombinant DNA.
D. genetic engineering.

4. A common vector used for cloning genes is/are
A. bacteria.
B. viruses.
C. nucleotides.
D. plasmids.

5. The molecules used as molecular scissors in genetic engineering is/are
A. exonucleases.
B. proteases.
C. restriction enzymes.
D. RNA polymerase.

6. Digestion of DNA by restriction enzymes
A. produces sticky ends.
B. produces blunt ends.
C. cuts both strands of the DNA molecule.
D. generates restriction fragments.
E. All of the choices are correct.

7. Restriction enzymes have proved so useful in manipulating DNA because
A. they cut at defined sites.
B. the sticky ends make it very easy to allow recombination of any type of DNA.
C. they protect eukaryotes against virus attack.
D. they cut RNA molecules.
E. they cut at defined sites AND the sticky ends make it very easy to allow recombination of any type of DNA.

8. The molecule(s) that act as molecular glue to bind DNA fragments together is/are
A. DNAse.
B. DNA ligase.
C. ligandase.
D. polymerase.
E. DNAse AND ligandase.

9. Agarose gel electrophoresis separates nucleic acid fragments according to
A. density.
B. shape.
C. size.
D. sequence.

10. A dye often used for its ease and sensitivity to visualize nucleic acid after agarose gel electrophoresis is
A. nigrosin.
B. malachite green.
C. gold oxide.
D. ethidium bromide.

11. The energy to separate fragments during agarose gel electrophoresis is supplied by
A. gravity.
B. active transport.
C. agarosis.
D. electricity.

12. The agarose used in electrophoresis
A. interacts electrically with the DNA.
B. chemically binds to the DNA.
C. acts as a sieve.
D. selectively sorts recombinant DNA from host DNA.

13. The gene for human insulin has been successfully cloned in
A. S. aureus.
B. yeast.
C. E. coli.
D. rhinovirus.

14. Genetic engineering
A. allows the use of bacteria as production factories for a number of molecules.
B. relies on recombinant DNA technology.
C. is dependent on RNA enzymes.
D. relies completely on conjugation.
E. allows the use of bacteria as production factories for a number of molecules AND relies on recombinant DNA technology.

15. Genetic engineering of plants has so far produced
A. pest resistant plants.
B. plants that are herbicide resistant.
C. plants with increased nutritional value.
D. All of the choices are correct.

16. The entire set of cloned fragments of the complete human genome is termed a
A. book of genes.
B. recombinant gene.
C. DNA library.
D. restructured genome.

17. An ideal vector
A. may be a plasmid or bacteriophage.
B. has a restriction enzyme recognition site.
C. contains an origin of replication.
D. contains a selectable marker.
E. All of the choices are correct.

18. Host cells containing recombinant DNA can be selected on the basis of the properties of the
A. vector.
B. ribosomes.
C. enzymes.
D. virus.

19. Selecting for transformants involves
A. identifying organisms that have taken up recombinant DNA.
B. searching for RNA.
C. production of proteins.
D. production of DNA.

20. Laboratory strains of E. coli are desirable hosts because
A. it is easy to grow.
B. its genetics is well known.
C. it is especially able to express foreign genes.
D. it has known phenotypic characteristics.
E. All of the choices are correct.

21. A danger in using E. coli in cloning is that
A. E. coli could cause disease.
B. the human cells may reject the insertion.
C. the exons may invert the introns.
D. the outer membrane is poisonous to humans.

22. When a vector that employs the lacZ’ gene as a second marker is used in a cloning experiment, bacteria that harbor the recombinant DNA will give rise to
A. red colonies.
B. white colonies.
C. blue colonies.
D. All of the choices are correct.

23. Goal(s) of gene cloning may be to produce
A. a protein.
B. many copies of the gene to be used as a probe.
C. many copies of the gene for sequencing.
D. more copies of the host cell.
E. a protein, many copies of the gene to be used as a probe AND many copies of the gene for sequencing.

24. In order to get around the lack of ability of prokaryotes to remove introns from precursor RNA, it may be necessary to
A. use the DNA directly.
B. use the DNA after it has been processed.
C. use different promoters.
D. turn mRNA into cDNA.
E. use the DNA directly AND use the DNA after it has been processed.

25. Which of the following genera has proved useful for manipulating plant cells?
A. Escherichia
B. Bacillus
C. Pseudomonas
D. Agrobacterium

26. The Ti plasmid is naturally found in
A. E. coli.
B. Pseudomonas.
C. Agrobacterium.
D. Staphylococcus.
E. E. coli AND Staphylococcus.

27. The Ti plasmid is used as a vector to transfer DNA into
A. viruses.
B. bacteria.
C. plant cells.
D. animal cells.

28. Genetically modified food has raised some concerns because
A. it contains radioactive particles.
B. it may contain some unanticipated allergens.
C. it may have some unintended environmental effects.
D. the modified DNA may transfer to other organisms.
E. it may contain some unanticipated allergens, it may have some unintended environmental effects AND the modified DNA may transfer to other organisms.

29. The current cost of sequencing a human genome is about
A. $ 10,000
B. $ 250,000
C. $ 1,000,000
D. $ 4,000,000

30. Knowing the sequence of a genome is useful in
A. identifying genetic alterations associated with disease.
B. studying evolutionary relationships.
C. determining protein sequences.
D. All of the choices are correct.

31. Dideoxynucleotides
A. are useful in nucleic acid sequencing.
B. have two additional hydroxyl groups at the 2′ and 3′ carbons.
C. act as chain initiators.
D. act as chain terminators.
E. are useful in nucleic acid sequencing AND act as chain terminators.

32. The polymerase chain reaction is used to duplicate small sections of
A. DNA.
B. RNA.
C. proteins.
D. lipids.

33. The polymerase chain reaction is used to
A. amplify certain sections of DNA.
B. amplify mRNA.
C. produce proteins.
D. produce long polymers of carbohydrates to be used in electrophoresis.

34. PCR is particularly useful in
A. detecting viable yet non-culturable organisms.
B. assessing impure (multiple types of bacteria present) samples.
C. dealing with very small numbers of bacteria.
D. relatively quickly producing results.
E. All of the choices are correct.

35. Double-stranded DNA will separate into two strands when exposed to
A. high temperature.
B. high pH.
C. low temperature.
D. low salt.
E. high temperature AND high pH.

36. Starting with a single piece of dsDNA, after 3 PCR cycles there are
A. 2 additional pieces of dsDNA.
B. 4 additional pieces of dsDNA.
C. 8 additional pieces of dsDNA.
D. 16 additional pieces of dsDNA.

37. Taq polymerase is
A. a reverse transcriptase.
B. an RNA polymerase.
C. from E. coli.
D. a heat stable DNA polymerase from Thermus aquaticus.
E. an RNA polymerase AND from E. coli.

38. PCR produces
A. DNA fragments of all possible sizes.
B. DNA fragments that are one nucleotide larger than the next fragment.
C. DNA fragments of a particular size.
D. DNA fragments of increasing size.
E. DNA fragments that are one nucleotide larger than the next fragment AND DNA fragments of increasing size.

39. The size of the amplified DNA fragment generated during PCR is determined by
A. how many cycles are performed.
B. the size of the template DNA.
C. the location to which the primers anneal.
D. how much Taq is used.

40. DNA probes
A. may be obtained from denatured tagged dsDNA.
B. may be obtained from similar genes from another organism.
C. may be synthesized usually using information based on the protein sequence.
D. are usually tagged dsRNA.
E. may be obtained from denatured tagged dsDNA, may be obtained from similar genes from another organism AND may be synthesized usually using information based on the protein sequence.

41. A common way to identify the E. coli that carries the desired recombinant DNA is by using a
A. vector.
B. probe.
C. host.
D. plasmid.

42. DNA microarray technology
A. may use many DNA fragments that function like probes.
B. attaches nucleotides to a solid support such as a glass slide.
C. relies on arrays that contain a detectable tag.
D. uses nucleic acid hybridization.
E. may use many DNA fragments that function like probes, attaches nucleotides to a solid support such as a glass slide AND uses nucleic acid hybridization.

43. Fluorescence in situ hybridization (FISH)
A. uses virus hosts.
B. uses a labeled probe.
C. is useful in microbial ecology.
D. allows identification of particular bacterial groups in mixed samples.
E. uses a labeled probe, is useful in microbial ecology AND allows identification of particular bacterial groups in mixed samples.

Matching Questions

44. Which of the following best matches the description:
1. Molecular scissors probe 4
2. Plasmid vector 2
3. A technique used to identify fragments of DNA on a nylon membrane colony blot 3
4. A small piece of tagged DNA recombinant DNA 5
5. Two different pieces of DNA linked together restriction endonuclease 1

True / False Questions

45. Agarose gel electrophoresis may be considered as a partial purification technique.
TRUE

46. Most eukaryotic genes are cloned directly into the vector for expression in prokaryotes.
FALSE

47. PCR is useful for amplifying a particular section of DNA.
TRUE

48. PCR typically results in the generation of fragments of all sizes.
FALSE

49. Vectors must have at least one restriction enzyme recognition site.
TRUE

50. A very common vector is a plasmid.
TRUE

51. When using lacZ’ containing vectors, colonies containing intact vector turn blue.
TRUE

52. DNA probes are used to find regions of complementary DNA.
TRUE

53. FISH uses labeled probes to detect specific whole cells.
TRUE

54. A DNA microarray contains oligonucleotides that contain a label.
TRUE

Essay Questions

55. What is the problem with putting a eukaryotic gene into a prokaryote?
The main difficulty faced when placing eukaryotic genes into prokaryotes is that eukaryotes process RNA to mRNA while prokaryotes do not. Thus, while the prokaryote may be able to transcribe the gene, it would be unable to produce a functional mRNA. The prokaryote would be unable to cut and splice the precursor RNA into a functional piece of mRNA. This inability of prokaryotes to process eukaryotic RNA is typically dealt with by using reverse transcriptase to turn the already processed eukaryotic mRNA into DNA, known as cDNA.

56. Why is a DNA fragment generated by PCR of essentially one particular size?
The size of the PCR fragment is initially variable. As the PCR progresses, more and more of the templates will end at the primer segments. Therefore, fairly quickly, the fragment size will be the same size as the segment defined by the primers.