Chapter 41 Recombinant DNA Techniques
Matching Questions
Use the following to answer questions 1–10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) ligase
b) restriction enzymes
c) DNA microarray
d) expression
e) Sanger
f) footprint
g) vector
h) E. coli
i) cDNA
j) reverse trancriptase
k) fluorescent
l) polymerase chain reaction
1.
_______________ are enzymes that split DNA at specific base-pair sequences.
2.
_______________ A collection of DNA sequences representing all of the mRNA expressed in a
particular cell type.
Ans:
Section: 41.1
3.
DNA sequencing by controlled termination of replication is called the ______________ method.
Ans:
Section: 41.3
4.
Instead of radioactivity, current DNA sequencing commonly uses _______________ base
analogues.
Ans:
k
Section: 41.3
5.
The enzyme that joins two DNA molecules is _______________.
Section: 41.3
6.
DNA sequences are amplified by the _______________.
Ans:
Section: 41.3
7.
A plasmid is an example of a common _______________.
Ans:
g
Section: 41.2
Ans:
b
Section: 41.2
Chapter 41 Recombinant DNA Techniques
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8.
_______________is a method for analyzing the expression of thousands of genes.
9.
_______________ is the enzyme used to create DNA from RNA.
Ans:
Section: 41.1
10.
The type of vector used for synthesis of protein is _______________.
Ans:
d
Section: 41.3
Fill–in-the-Blank Questions
11.
The enzyme that catalyzes the formation of a phosphodiester linkage at a break in a DNA strand
is _____.
Ans: DNA ligase Section: 41.3
12.
_____ cleave DNA at sites with inverted repeat sequences referred to as palindromic sequences.
Ans: Restriction endonucleases Section: 41.2
13.
Complementary, single-strand overhangs that are produced by some restriction endonucleases
are referred to as _____.
Ans: sticky ends or cohesive ends Section: 41.2
14.
The Sanger technique for sequencing DNA involves the use of _____nucleotide analogs that
terminate chain elongation.
Ans: 2,3-dideoxy Section: 41.3
15.
The technique in which DNA fragments are separated by electrophoresis and identified using a
radiolabeled probe is called _____.
Ans: Southern blotting Section: 41.2
16.
PCR is the abbreviation for _____, which is an in vitro technique used to make multiple copies
of a DNA molecule.
Ans: polymerase chain reaction Section: 41.3
17.
Bacterial plasmid DNA and bacteriophage DNA are commonly used _____ to introduce foreign
DNA into a bacterium.
Ans: vectors Section: 41.1
18.
The enzyme _____ can be used to add nucleotides to the 3 end of DNA.
Ans: terminal transferase Section: 41.3
19.
Complementary DNA (cDNA) is formed by the action of reverse transcriptase on _____.
Ans: mRNA Section: 41.3
Ans:
Section: 41.2
Chapter 41 Recombinant DNA Techniques
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20.
DNA fragments can be visualized in polyacrylamide-gel electrophoresis by staining with _____,
which binds to double-stranded DNA and fluoresces an intense orange when irradiated by UV
light.
Multiple-Choice Questions
21.
The biological role of restriction enzymes in bacteria is to
A)
repair DNA.
B)
induce DNA crossover.
C)
cleave foreign DNA.
D)
All of the above.
E)
None of the above.
Ans: C Section: 41.2
22.
Which of the following DNA sequences contains a 4−8 base palindromic site? (Note: Only one
strand is shown.)
A)
CAGTCC
B)
GCATCC
C)
CGATTAGC
D)
GAGAGAGA
E)
GCATATGC
Ans: E Section: 41.2
23.
What do Southern, Northern, and Western blots detect, respectively?
A)
DNA, RNA, and protein
B)
DNA, protein, and RNA
C)
RNA, DNA, and protein
D)
protein, DNA, and RNA
E)
RNA, protein, and DNA
Ans: A Section: 41.2
24.
The specificity or stringency of a PCR reaction can be controlled by altering the reaction
A)
volume.
B)
target sequence.
C)
temperature and salt concentration.
D)
All of the above.
E)
None of the above.
Ans: C Section: 41.3
25.
Reagents necessary for sequencing by chain termination include:
A)
template DNA, deoxyribonucleoside triphosphates (dNTPs), primer, dideoxynucleotide
analogs, DNA polymerase, and radioactive probe.
B)
template DNA, dNTPs, primer, dideoxynucleotide analogs, and DNA polymerase.
C)
template DNA, dNTPs, primer, dideoxynucleotide analogs, and RNA polymerase.
D)
All of the above.
E)
None of the above.
Ans: B Section: 41.3
Ans: ethidium bromide Section: 41.2
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26.
Plasmids used in recombinant DNA technology typically
A)
possess a gene for antibiotic resistance.
B)
replicate independently of the host genome.
C)
are circular double-stranded molecules.
D)
All of the above.
E)
A and B.
27.
For identification of a gene, against which strand of DNA must the probe complement?
A)
either strand
B)
both strands
C)
only the coding strand
D)
only the template strand
E)
None of the above.
Ans: A Section: 41.2
28.
Reverse transcriptase is normally found in
A)
plants.
B)
retrovirus.
C)
mitochondria.
D)
All of the above.
E)
None of the above.
Ans: B Section: 41.3
29.
The probe used to isolate a gene from a genomic library is often
A)
the ligand that binds to the protein.
B)
its promoter region.
C)
a portion of the mRNA of the gene.
D)
All of the above.
E)
None of the above.
Ans: C Section: 41.1
30.
A technique used to identify RNA after gel electrophoresis and which employs ssDNA in the
detection process is
A)
none of the below.
B)
the Southwestern blot.
C)
the Western blot.
D)
the Southern blot.
E)
the Northern blot.
Ans: E Section: 41.2
Ans: D Section: 41.3
Chapter 41 Recombinant DNA Techniques
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31.
Which of the following would more likely yield a more optimal oligonucleotide probe, one with
tryptophan and methionine or one with serine and leucine?
A)
It is impossible to predict the optimal nucleotide sequence, which is why poly-U
nucleotides are generally used.
B)
The amino acids coded by codons, where all three positions can be the same nucleotide,
generate the optimal oligonucleotide; therefore, serine and leucine.
C)
The amino acids coded by codons, where the first two positions are the same, generate
the optimal oligonucleotide; therefore, serine and leucine.
D)
The amino acids with the least number of codons would not provide enough variation for
all necessary oligonucleotides; therefore, leucine and serine.
E)
The amino acids with the least number of codons would require the fewest number of
nucleotide probes; therefore, tryptophan and methionine.
32.
In the controlled termination method of DNA sequencing, in what direction do you read the
nucleotide sequence and why?
A)
Reading the gel from the top to the bottom gives the sequence in the 5 to 3 direction;
shorter fragments that were terminated early in polymerization move faster down the gel.
B)
Reading the gel from the top to the bottom gives the sequence in the 5 to 3 direction;
longer fragments that were terminated early in polymerization move faster down the gel.
C)
Reading the gel from the bottom to the top gives the sequence in the 5 to 3 direction;
shorter fragments that were terminated early in polymerization move faster down the gel.
D)
Reading the gel from the bottom to the top gives the sequence in the 5 to 3 direction;
longer fragments that were terminated later in polymerization move faster down the gel.
E)
Reading the gel from the bottom to the top gives the sequence in the 3 to 5 direction;
shorter fragments that were terminated early in polymerization move faster down the gel.
Ans: C Section: 41.3
33.
Controlling stringency may be the most important parameter in PCR. If you want to check a
gene from two distantly related species, for example, humans vs. zooplankton, what kinds of
stringency measures would you take?
A)
Start PCR annealing temperatures high to see if there are similar sequences.
B)
Lower PCR annealing temperatures slowly if no product is formed.
C)
Adjust salt concentrations to achieve maximum ionic strength.
D)
Synthesize primers corresponding to the ends of the gene.
E)
All of the above.
Ans: E Section: 41.3
34.
How does the genome differ from the transcriptome?
A)
The genome is all of the genes in the DNA of a species, whereas the transcriptome is only
those that are unique to an individual.
B)
The genome is all of the genes in the DNA of a cell, whereas the transcriptome is only
those that are expression within a specific tissue.
C)
The genome is the genes that encode for proteins in a cell, whereas the transcriptome is
only those proteins that are needed for steady-state levels of a particular cell.
D)
The transcriptome is all genes that can be transcribed by a cell, whereas the genome is the
complete DNA sequence of the cell.
E)
The genome does not contain untranslated regions of the DNA but the transcriptome
include all transcribed regions of the DNA.
Ans: B Section: 41.3
Ans: E Section: 41.1
Chapter 41 Recombinant DNA Techniques
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35.
What technique has become a valuable tool in forensics and legal medicine?
A)
PCR
B)
pyrosequencing
C)
ion semiconductor sequencing
D)
controlled termination of replication
E)
genomic library screening
Short-Answer Questions
36.
A number of tools are critical to gene exploration. Name at least four.
Section: 41.3
37.
Design a potential DNA-restriction enzyme site. Show both strands.
Ans:
Any palindromic site of four or more base pairs would be appropriate.
Section: 41.2
38.
How can DNA fragments of various sizes be separated?
including ethidium bromide staining, or autoradiography.
Section: 41.2
39.
What is a DNA probe?
detection using radioactivity or another tag, such as fluorescent probes.
Section: 41.1
40.
What is the basis of the Sanger method?
dye tags can also be used in an automated process.)
Section: 41.3
Ans: A Section: 41.3
Chapter 41 Recombinant DNA Techniques
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41.
Explain the basis of the polymerase chain reaction.
42.
Describe two ways PCR can be used in medical diagnosis.
43.
Briefly outline the steps necessary to create a recombinant DNA molecule.
DNA ligase is added to join the ends.
44.
How is a single gene of interest identified on a plate containing many different library clones?
detected and the proper clone identified and selected.
Section: 41.3
45.
Briefly outline how a cDNA library is made.
inserted into a vector, and then into a host such as bacteria.
46.
How is gene disruption used to determine the function of a gene?
Section: 41.2
47.
What is a transcriptome?
or tissue.
and cooling steps.
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48.
Why are monoclonal antibodies more useful than polyclonal antibodies?
49.
How does quantitative PCR differ from nonquantitative PCR?
This is a measure of expression of the gene involved.
Section: 41.3
50.
Describe the technique called a DNA microarray.
level of expression is determined by the level of fluorescence.
Section: 41.3
mechanisms.
Section: 41.3