B_T_2015_02_

(Michael S) #1

  1. The basic procedure involved in the synthesis of
    recombinant DNa molecule is depicted below. The
    mistake in the procedure is


(a) enzyme polymerase is not included.
(b) the mammalian DNa is shown double stranded.
(c) two different restriction enzymes are used.
(d) only one fragment is inserted.


  1. a plasmid has two antibiotic resistance genes, one for
    ampicillin and one for tetracycline. It is treated with
    a restriction enzyme that cuts in the middle of the
    ampicillin gene. DNa fragments containing a human
    globin gene were cut with the same enzyme. The
    plasmids and fragments are mixed, treated with ligase,
    and used to transform bacterial cells. Clones that have
    taken up the recombinant DNa are the ones that
    (a) are blue and can grow on plates with both
    antibiotics.
    (b) can grow on plates with ampicillin but not with
    tetracycline.
    (c) can grow on plates with tetracycline but not with
    ampicillin.
    (d) cannot grow with any antibiotics.

  2. 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.

  3. The diagram shows a section of a DNa molecule.
    aTCGTaGaaTTCGGCTCGaGGCaTTaGaaTTCCTaGGaTCGaaTTGG
    TaGCaTCTTaaGCCGaGCTCCGTaaTCTTaaGGaTCCTa GCTTaaCC


This molecule was cut under ideal conditions, using
two different endonucleases, Eco r1 and Tac1, which
recognize different restriction sites.


Eco r 1 GaaTTC Tac 1 TCGa
CTTaaG aGCT
What is the number of DNa fragments that can be
produced?
(a) 4 (b) 6 (c) 5 (d) 8


  1. at the start of the Polymerase Chain reaction (PCr),
    single stranded primers are added to the denatured
    DNa and the mixture is cooled to 60°C.
    What explains why the denatured DNa strands anneal
    with primers and not with each other?
    (a) The primers are shorter and anneal more easily.
    (b) The primers anneal only to the 3’ end of denatured
    DNa.
    (c) The primer concentration exceeds the denatured
    DNa concentration.
    (d) The temperature prevents the denatured DNa
    from annealing together.

  2. Bam H1 is a restriction enzyme that cuts DNa having a
    specific sequence.
    The diagram below shows part of the procedure for
    producing E. coli that will synthesize human growth
    hormone, hGH.


at the end of this process, many plasmids do not contain
the hGH gene. What could explain this?
(a) Different alleles of the hGH gene have different
sticky ends.
(b) Not all of the plasmids cut by Bam H1 have sticky
ends.
(c) Some of the plasmids are cut at more than one
position.
(d) The sticky ends of some of the plasmids rejoin
with each other.
Answer Key


  1. (c) 2. (a) 3. (c) 4. (c) 5. (a)

  2. (d) 7. (b) 8. (d) 9. (a) 10. (b)

  3. (b) 12. (c) 13. (b) 14. (b) 15. (b)

  4. (b) 17. (c) 18. (a) 19. (b) 20. (d)
    Higher Order Thinking Skills Questions (HOTS)

  5. (a) 22. (a) 23. (b) 24. (c) 25. (c)

  6. (c) 27. (c) 28. (c) 29. (c) 30. (d)
    nn

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