Quiz: Selection, Screening, And Analysis Of Recombinant DNA

50 Questions | Total Attempts: 115

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Quiz: Selection, Screening, And Analysis Of Recombinant DNA

The study of human DNA has led to a lot of medical breakthroughs and did you know that science has advanced so much that one can actually create DNA molecules in the laboratory and even be combined to form a new genetic sequence? The quiz below is designed to test out just how much you know about selection, screening, and analysis when it comes to recombinant DNA.


Questions and Answers
  • 1. 
    Success in any cloning experiment depends on being able to identify the desired gene sequence among the many different recombinants that may be produced.
    • A. 

      TRUE

    • B. 

      FALSE

  • 2. 
    Selection is where some sort of pressure (e.g. the presence of an antibiotic) is applied during the growth of host cells containing recombinant DNA.
    • A. 

      TRUE

    • B. 

      FALSE

  • 3. 
    Screening is a procedure by which a population of viable cells is subjected to some sort of analysis that enables the desired sequences to be identified.
    • A. 

      TRUE

    • B. 

      FALSE

  • 4. 
    Antibiotic resistance marker genes provide a simple and reliable way to select for the presence of vectors in cells.
    • A. 

      TRUE

    • B. 

      FALSE

  • 5. 
    Genetic selection and screening methods rely on the expression (or non-expression) of certain traits.
    • A. 

      TRUE

    • B. 

      FALSE

  • 6. 
    One of the simplest genetic selection methods involves the use of antibiotics to select for the presence of vector molecules.
    • A. 

      TRUE

    • B. 

      FALSE

  • 7. 
    The plasmid pBR322 contains genes for ampicillin resistance (Apr) and tetracycline resistance (Tcr).
    • A. 

      TRUE

    • B. 

      FALSE

  • 8. 
    The presence of the plasmid pBR322 in cells can be detected by plating potential transformants on an agar medium that contains either (or both) of ampicillin and tetracycline antibiotics.
    • A. 

      TRUE

    • B. 

      FALSE

  • 9. 
    The X-gal detection system can be used where a functional β-galactosidase gene is present in the host/vector system.
    • A. 

      TRUE

    • B. 

      FALSE

  • 10. 
    The presence of cloned DNA fragments can be detected if the insert interrupts the coding sequence of a gene.
    • A. 

      TRUE

    • B. 

      FALSE

  • 11. 
    Origin of replication can be used to identify a vector carrying a cloned insert.
    • A. 

      TRUE

    • B. 

      FALSE

  • 12. 
    Antibiotic resistance can not be used as an insertional inactivation system if DNA fragments are cloned into a restriction site within an anitbiotic-resistance gene.
    • A. 

      TRUE

    • B. 

      FALSE

  • 13. 
    Plaque morphology can not also be used as a screening method for certain λ vectors such as λgt10, which contain the cI gene.
    • A. 

      TRUE

    • B. 

      FALSE

  • 14. 
    The LacZ gene encodes the cI repressor, which is responsible for the formation of lysogens
    • A. 

      TRUE

    • B. 

      FALSE

  • 15. 
    Direct complementation of a defined mutation may be feasible if the gene system is unknown and an appropriate mutant is available.
    • A. 

      TRUE

    • B. 

      FALSE

  • 16. 
    The antiparalel nature of DNA strands means that a sequence-specific probe is a very powerful screening tool.
    • A. 

      TRUE

    • B. 

      FALSE

  • 17. 
    Nucleic acid hybridisation is a very powerful method to screen clone banks and is one of the key techniques to amplify a gene.
    • A. 

      TRUE

    • B. 

      FALSE

  • 18. 
    The production of a cDNA or genomic DNA library is often termed the ‘blotting’ approach, as a large number of essentially random recombinants is generated.
    • A. 

      TRUE

    • B. 

      FALSE

  • 19. 
    By using a defined nucleic acid probe, a cDNA or genomic DNA library can be cleaved and the clone(s) of interest identified.
    • A. 

      TRUE

    • B. 

      FALSE

  • 20. 
    Homologous or heterologous probes may be used in screening protocols, if genes have sequences similar enough to enable hybridisation to be unstable under relatively high stringency conditions.
    • A. 

      TRUE

    • B. 

      FALSE

  • 21. 
    The power of nucleic acid hybridisation lies in the fact that complementary sequences will bind to each other with a very high degree of fidelity.
    • A. 

      TRUE

    • B. 

      FALSE

  • 22. 
    There are three main types of DNA probe: (1) cDNA, (2) genomic DNA, and (3) oligonucleotides.
    • A. 

      TRUE

    • B. 

      FALSE

  • 23. 
    The availability of a particular probe will depend on what is known about the target gene sequence.
    • A. 

      TRUE

    • B. 

      FALSE

  • 24. 
    If a cDNA clone has already been obtained and identified, the cDNA can be used to screen a genomic library and isolate the gene sequence itself.
    • A. 

      TRUE

    • B. 

      FALSE

  • 25. 
    Genomic DNA probes are usually fragments of cloned sequences that are used either as heterologous probes or to identify other clones that contain additional parts of the gene in question.
    • A. 

      TRUE

    • B. 

      FALSE

  • 26. 
    The use of oligonucleotide probes is possible where some amino acid sequence data are available for the protein encoded by the target gene.
    • A. 

      TRUE

    • B. 

      FALSE

  • 27. 
    The degenerate nature of the genetic code means that it is not possible to predict the sequence with complete accuracy.
    • A. 

      TRUE

    • B. 

      FALSE

  • 28. 
    The availability of genome sequences means that computer-based searches can be used to find particular genes.
    • A. 

      TRUE

    • B. 

      FALSE

  • 29. 
    Assuming that the genome sequence for your target organism is available, a computer can be used to search for any particular sequence in the genome.
    • A. 

      TRUE

    • B. 

      FALSE

  • 30. 
    When a suitable probe has been obtained, it can be labelled with a radioactive isotope such as 32P.
    • A. 

      TRUE

    • B. 

      FALSE

  • 31. 
    Amplicon can be screened by producing a copy of the colonies (or plaques) on a nitrocellulose or nylon filter.
    • A. 

      TRUE

    • B. 

      FALSE

  • 32. 
    Hybridisation is the joining together of artificially separated nucleic acid molecules via phosphodiester bonding between complementary bases.
    • A. 

      TRUE

    • B. 

      FALSE

  • 33. 
    An important factor in screening genomic libraries by nucleic acid hybridisation is the number of plaques that can be cleaved on each filter.
    • A. 

      TRUE

    • B. 

      FALSE

  • 34. 
    Ligation can be used for screening clone libraries.
    • A. 

      TRUE

    • B. 

      FALSE

  • 35. 
    Antibody screening enables the specific identification of carhohydrate that are synthesised from expression libraries.
    • A. 

      TRUE

    • B. 

      FALSE

  • 36. 
    An alternative to screening with nucleic acid probes is to identify the protein product of a cloned gene by PCR screening.
    • A. 

      TRUE

    • B. 

      FALSE

  • 37. 
    Antibodies are produced by animals in response to challenge with an antigen, which is normally a purified DNA
    • A. 

      TRUE

    • B. 

      FALSE

  • 38. 
    Polyclonal antisera contain antibodies that recognise single antigenic antigenic determinants of the antigen.
    • A. 

      TRUE

    • B. 

      FALSE

  • 39. 
    Monoclonal antibodies recognise all the antigenic determinant.
    • A. 

      TRUE

    • B. 

      FALSE

  • 40. 
    Matching the cloned sequence with the plasmid that it encodes can sometimes be useful in clone identification.
    • A. 

      TRUE

    • B. 

      FALSE

  • 41. 
    Hybrid-arrest translation (HART) and hybrid-release translation (HRT, sometimes called hybrid-select translation) are possible used to identify the protein product.
    • A. 

      TRUE

    • B. 

      FALSE

  • 42. 
    Both HART and HRT rely on hybridising cloned DNA fragments to mRNA prepared from the cell or tissue type from which the clones have been derived.
    • A. 

      TRUE

    • B. 

      FALSE

  • 43. 
    Generating a restriction map of a cloned DNA fragment is usually one of the first tasks in analysing the clone.
    • A. 

      TRUE

    • B. 

      FALSE

  • 44. 
    The basic principle of restriction mapping is the cloned DNA is usually cut with a variety or restriction enzymes to determine the number of fragments produced by each enzyme.
    • A. 

      TRUE

    • B. 

      FALSE

  • 45. 
    Blotting techniques, when used with restriction enzyme digestion and gel electrophoresis, can be used to identify particular regions of a gene in a cloned fragment of DNA.
    • A. 

      TRUE

    • B. 

      FALSE

  • 46. 
    The first blotting technique was developed by Ed Southern, and is eponymously known as Southern blotting.
    • A. 

      TRUE

    • B. 

      FALSE

  • 47. 
    Northern blotting is most useful in determining hybridisation patterns in mRNA samples and can be used to determine which regions of a cloned DNA fragment will hybridise to a particular mRNA.
    • A. 

      TRUE

    • B. 

      FALSE

  • 48. 
    Blotting without separation of sequences can be a useful technique for determining the amount of a specific sequence in a sample – often this is used to measure transcript levels in gene expression studies.
    • A. 

      TRUE

    • B. 

      FALSE

  • 49. 
    Determining the sequence of a cloned fragment is usually essential if gene structure is being studied.
    • A. 

      TRUE

    • B. 

      FALSE

  • 50. 
    Sequencing can range from a small-scale project involving a single gene up to sequencing entire genomes.
    • A. 

      TRUE

    • B. 

      FALSE