1. Assume that you are trying to insert a gene into a
plasmid. Someone gives you a preparation of genomic DNA that has been cut with
restriction enzyme X. The gene you wish to insert has sites on both ends for
cutting by restriction enzyme Y. You have a plasmid with a single site for Y,
but not for X. Your strategy should be to
A) insert the fragments cut with restriction enzyme X
directly into the plasmid without cutting the plasmid.
B) cut the plasmid with restriction enzyme X and insert
the fragments cut with restriction enzyme Y into the plasmid.
C) cut the DNA again with restriction enzyme Y and insert
these fragments into the plasmid cut with the same enzyme.
D) cut the plasmid twice with restriction enzyme Y and
ligate the two fragments onto the ends of the DNA fragments cut with
restriction enzyme X.
E) cut the plasmid with restriction enzyme X and then
insert the gene into the plasmid.
Answer: C
2) How does a bacterial cell protect its own DNA from
restriction enzymes?
A) by adding methyl groups to adenines and cytosines
B) by using DNA ligase to seal the bacterial DNA into a
closed circle
C) by adding histones to protect the double-stranded DNA
D) by forming "sticky ends" of bacterial DNA to
prevent the enzyme from attaching
E) by reinforcing the bacterial DNA structure with
covalent phosphodiester bonds
Answer: A
3) What is the most logical sequence of steps for
splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium?
I. Transform bacteria with a 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.
A) I, II, IV, III, V
B) II, III, V, IV, I
C) III, II, IV, V, I
D) III, IV, V, I, II
E) IV, V, I, II, III
Answer: C
4) A principal problem with inserting an unmodified
mammalian gene into a BAC, and then getting that gene expressed in bacteria, 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 membrane-bounded
nucleus and is therefore incompatible with mammalian DNA.
Answer: C
5) A gene that contains introns can be made shorter (but
remain functional) for genetic engineering purposes by using
A) RNA polymerase to transcribe the gene.
B) a restriction enzyme to cut the gene into shorter
pieces.
C) reverse transcriptase to reconstruct the gene from its
mRNA.
D) DNA polymerase to reconstruct the gene from its
polypeptide product.
E) DNA ligase to put together fragments of the DNA that
code for a particular polypeptide.
Answer: C
6) Why are yeast cells frequently used as hosts for
cloning?
A) They easily form colonies.
B) They can remove exons from mRNA.
C) They do not have plasmids.
D) They are eukaryotic cells.
E) Only yeast cells allow the gene to be cloned.
Answer: D
7) The DNA fragments making up a genomic library are
generally contained in
A) BACs.
B) recombinant viral RNA.
C) individual wells.
D) DNA-RNA hybrids.
E) radioactive eukaryotic cells.
Answer: A
8) Yeast artificial chromosomes contain which of the
following elements?
A) centromeres only
B) telomeres only
C) origin of replication only
D) centromeres and telomeres only
E) centromeres, telomeres, and an origin of replication
Answer: E
9) Which of the following best describes the complete
sequence of steps occurring during every cycle of PCR?
1. The primers hybridize to the target DNA.
2. The mixture is heated to a high temperature to
denature the double-stranded target DNA.
3. Fresh DNA polymerase is added.
4. DNA polymerase extends the primers to make a copy of
the target DNA.
A) 2, 1, 4
B) 1, 3, 2, 4
C) 3, 4, 1, 2
D) 3, 4, 2
E) 2, 3, 4
Answer: A
10) A researcher needs to clone a sequence of part of a
eukaryotic genome in order to express the sequence and to modify the
polypeptide product. She would be able to satisfy these requirements by using
which of the following vectors?
A) a bacterial plasmid
B) BAC to accommodate the size of the sequence
C) a modified bacteriophage
D) a human chromosome
E) a YAC with appropriate cellular enzymes
Answer: E
11) A student wishes to clone a sequence of DNA of ~200
kb. Which vector would be appropriate?
A) a plasmid
B) a typical bacteriophage
C) a BAC
D) a plant virus
E) a large polypeptide
Answer: C
12) Sequencing an entire genome, such as that of C.
elegans, a nematode, is most important because
A) it allows researchers to use the sequence to build a
"better" nematode, which is resistant to disease.
B) it allows research on a group of organisms we do not
usually care much about.
C) the nematode is a good animal model for trying out
cures for viral illness.
D) a sequence that is found to have a particular function
in the nematode is likely to have a closely related function in vertebrates.
E) a sequence that is found to have no introns in the
nematode genome is likely to have acquired the introns from higher organisms.
Answer: D
13) To introduce a particular piece of DNA into an animal
cell, such as that of a mouse, you would find more probable success with which
of the following methods?
A) the shotgun approach
B) electroporation followed by recombination
C) introducing a plasmid into the cell
D) infecting the mouse cell with a Ti plasmid
E) transcription and translation
Answer: B
14) The major advantage of using artificial chromosomes
such as YACs and BACs for cloning genes is that
A) plasmids are unable to replicate in cells.
B) only one copy of a plasmid can be present in any given
cell, whereas many copies of a YAC or BAC can coexist in a single cell.
C) YACs and BACs can carry much larger DNA fragments than
ordinary plasmids can.
D) YACs and BACs can be used to express proteins encoded
by inserted genes, but plasmids cannot.
E) All of these are correct.
Answer: C
15) Which of the following is used to make complementary
DNA (cDNA) from RNA?
A) restriction enzymes
B) gene cloning
C) DNA ligase
D) gel electrophoresis
E) reverse transcriptase
Answer: E
16) Why is it so important to be able to amplify DNA
fragments when studying genes?
A) DNA fragments are too small to use individually.
B) A gene may represent only a millionth of the cell's
DNA.
C) Restriction enzymes cut DNA into fragments that are
too small.
D) A clone requires multiple copies of each gene per
clone.
E) It is important to have multiple copies of DNA in the
case of laboratory error.
Answer: B
17) Pax-6 is a gene that is involved in eye formation in
many invertebrates, such as Drosophila. Pax-6 is found as well in vertebrates.
A Pax-6 gene from a mouse can be expressed in a fly and the protein (PAX-6)
leads to a compound fly eye. This information suggests which of the following?
A) Pax-6 genes are identical in nucleotide sequence.
B) PAX-6 proteins have identical amino acid sequences.
C) Pax-6 is highly conserved and shows shared
evolutionary ancestry.
D) PAX-6 proteins are different for formation of
different kinds of eyes.
E) PAX-6 from a mouse can function in a fly, but a fly's
Pax-6 gene cannot function in a mouse.
Answer: C
18) Why are BACs preferred today rather than
bacteriophages for making genomic libraries?
A) The BAC carries more DNA.
B) The BAC can carry entire genes and their regulatory
elements.
C) Larger BACs are easier to store.
D) The BAC can carry entire genes and their regulatory
elements, and larger BACs are easier to store.
E) The BAC carries more DNA, the BAC can carry entire
genes and their regulatory elements, and larger BACs are easier to store.
Answer: E
19) The reason for using Taq polymerase for PCR is that
A) it is heat stable and can withstand the temperature
changes of the cycler.
B) only minute amounts are needed for each cycle of PCR.
C) it binds more readily than other polymerases to
primer.
D) it has regions that are complementary to primers.
E) All of these are correct.
Answer: A
20) Why might a laboratory be using dideoxy nucleotides?
A) to separate DNA fragments
B) to clone the breakpoints of cut DNA
C) to produce cDNA from mRNA
D) to sequence a DNA fragment
E) to visualize DNA expression
Answer: D
21) In order to identify a specific restriction fragment
using a probe, what must be done?
A) The fragments must be separated by electrophoresis.
B) The fragments must be treated with heat or chemicals
to separate the strands of the double helix.
C) The probe must be hybridized with the fragment.
D) The fragments must be separated by electrophoresis and
the fragments must be treated with heat or chemicals to separate the strands of
the double helix.
E) The fragments must be separated by electrophoresis,
the fragments must be treated with heat or chemicals to separate the strands of
the double helix, and the probe must be hybridized with the fragment.
Answer: E
22) Which of the following modifications is least likely
to alter the rate at which a DNA fragment moves through a gel during
electrophoresis?
A) altering the nucleotide sequence of the DNA fragment
B) methylating the cytosine bases within the DNA fragment
C) increasing the length of the DNA fragment
D) decreasing the length of the DNA fragment
E) neutralizing the negative charges within the DNA
fragment
Answer: A
23) DNA fragments from a gel are transferred to a
nitrocellulose paper during the procedure called Southern blotting. What is the
purpose of transferring the DNA from a gel to a nitrocellulose paper?
A) to attach the DNA fragments to a permanent substrate
B) to separate the two complementary DNA strands
C) to transfer only the DNA that is of interest
D) to prepare the DNA for digestion with restriction
enzymes
E) to separate out the PCRs
Answer: A
24) DNA microarrays have made a huge impact on genomic
studies because they
A) can be used to eliminate the function of any gene in
the genome.
B) can be used to introduce entire genomes into bacterial
cells.
C) allow the expression of many or even all of the genes
in the genome to be compared at once.
D) allow physical maps of the genome to be assembled in a
very short time.
E) dramatically enhance the efficiency of restriction
enzymes.
Answer: C
25) Which of the following describes the transfer of
polypeptide sequences to a membrane to analyze gene expression?
A) Southern blotting
B) Northern blotting
C) Western blotting
D) Eastern blotting
E) RT-PCR
Answer: C
26) Which of the following uses reverse transcriptase to
make cDNA followed by amplification?
A) Southern blotting
B) Northern blotting
C) Western blotting
D) Eastern blotting
E) RT-PCR
Answer: E
27) RNAi methodology uses double-stranded pieces of RNA
to trigger a breakdown or blocking of mRNA. For which of the following might it
more possibly be useful?
A) to raise the rate of production of a needed digestive
enzyme
B) to decrease the production from a harmful
gain-of-function mutated gene
C) to destroy an unwanted allele in a homozygous
individual
D) to form a knockout organism that will not pass the
deleted sequence to its progeny
E) to raise the concentration of a desired protein
Answer: B
28) A researcher has used in vitro mutagenesis to mutate
a cloned gene and then has reinserted this into a cell. In order to have the
mutated sequence disable the function of the gene, what must then occur?
A) recombination resulting in replacement of the wild
type with the mutated gene
B) use of a microarray to verify continued expression of
the original gene
C) replication of the cloned gene using a bacterial
plasmid
D) transcription of the cloned gene using a BAC
E) attachment of the mutated gene to an existing mRNA to
be translated
Answer: A
29) Which of the following techniques used to analyze
gene function depends on the specificity of DNA base complementarity?
A) Northern blotting
B) use of RNAi
C) in vitro mutagenesis
D) in situ hybridization
E) restriction fragment analysis
Answer: C
30) Silencing of selected genes is often done using RNA
interference (RNAi). Which of the following questions would not be answered
with this process?
A) What is the function of gene 432 in this species of
annelid?
B) What will happen in this insect's digestion if gene
173 is not able to be translated?
C) Is gene HA292 responsible for this disorder in humans?
D) Will the disabling of this gene in Drosophila and in a
mouse cause similar results?
E) Is the gene on Drosophila chromosome 2L at this locus
responsible for part of its production of nitrogen waste?
Answer: C
31) In large scale, genome-wide association studies in
humans, correlation is sought between
A) lengthy sequences that might be shared by most members
of a population.
B) single nucleotide polymorphisms found only in persons
with a particular disorder.
C) single nucleotide polymorphisms found in families with
a particular introns sequence.
D) single nucleotide polymorphisms in two or more
adjacent genes.
E) large inversions that displace the centromere.
Answer: B
32) For a particular microarray assay (DNA chip), cDNA
has been made from the mRNAs of a dozen patients' breast tumor biopsies. The
researchers will be looking for
A) a particular gene that is amplified in all or most of
the patient samples.
B) a pattern of fluorescence that indicates which cells
are overproliferating.
C) a pattern shared among some or all of the samples that
indicates gene expression differing from control samples.
D) a group of cDNAs that act differently from those on
the rest of the grid.
E) a group of cDNAs that match those in non-breast cancer
control samples from the same population.
Answer: C
33) Which of the following is most closely identical to
the formation of twins?
A) cell cloning
B) therapeutic cloning
C) use of adult stem cells
D) embryo transfer
E) organismal cloning
Answer: E
34) In 1997, Dolly the sheep was cloned. Which of the following
processes was used?
A) use of mitochondrial DNA from adult female cells of
another ewe
B) replication and dedifferentiation of adult stem cells
from sheep bone marrow
C) separation of an early stage sheep blastula into
separate cells, one of which was incubated in a surrogate ewe
D) fusion of an adult cell's nucleus with an enucleated
sheep egg, followed by incubation in a surrogate
E) isolation of stem cells from a lamb embryo and
production of a zygote equivalent
Answer: D
35) Which of the following problems with animal cloning
might result in premature death of the clones?
A) use of pluripotent instead of totipotent stem cells
B) use of nuclear DNA as well as mtDNA
C) abnormal regulation due to variant methylation
D) the indefinite replication of totipotent stem cells
E) abnormal immune function due to bone marrow
dysfunction
Answer: C
36) Reproductive cloning of human embryos is generally
considered unethical. However, on the subject of therapeutic cloning there is a
wider divergence of opinion. Which of the following is a likely explanation?
A) Use of adult stem cells is likely to produce more cell
types than use of embryonic stem cells.
B) Cloning to produce embryonic stem cells may lead to
great medical benefits for many.
C) Cloning to produce stem cells relies on a different
initial procedure than reproductive cloning.
D) A clone that lives until the blastocyst stage does not
yet have human DNA.
E) No embryos would be destroyed in the process of
therapeutic cloning.
Answer: B
37) Which of the following is true of embryonic stem
cells but not of adult stem cells?
A) They can differentiate into many cell types.
B) They make up the majority of cells of the tissue from
which they are derived.
C) They can continue to replicate for an indefinite
period.
D) They can provide enormous amounts of information about
the process of gene regulation.
E) One aim of using them is to provide cells for repair
of diseased tissue.
Answer: B
38) A researcher is using adult stem cells and comparing
them to other adult cells from the same tissue. Which of the following is a
likely finding?
A) The cells from the two sources exhibit different
patterns of DNA methylation.
B) Adult stem cells have more DNA nucleotides than their
counterparts.
C) The two kinds of cells have virtually identical gene
expression patterns in microarrays.
D) The nonstem cells have fewer repressed genes.
E) The nonstem cells have lost the promoters for more
genes.
Answer: A
39) In animals, what is the difference between
reproductive cloning and therapeutic cloning?
A) Reproductive cloning uses totipotent cells, whereas
therapeutic cloning does not.
B) Reproductive cloning uses embryonic stem cells,
whereas therapeutic cloning does not.
C) Therapeutic cloning uses nuclei of adult cells
transplanted into enucleated nonfertilized eggs.
D) Therapeutic cloning supplies cells for repair of
diseased or injured organs.
Answer: D
40) The first cloned cat, called Carbon Copy, was a
calico, but she looked significantly different from her female parent. Why?
A) The environment, as well as genetics, affects
phenotypic variation.
B) Fur color genes in cats are influenced by differential
acetylation patterns.
C) Cloned animals have been found to have a higher
frequency of transposon activation
D) X inactivation in the embryo is random and produces
different patterns.
E) The telomeres of the parent's chromosomes were shorter
than those of an embryo.
Answer: D
41) In recent times, it has been shown that adult cells
can be induced to become pluripotent stem cells (iPS). In order to make this
conversion, what has been done to the adult cells?
A) A retrovirus is used to introduce four specific
regulatory genes.
B) The adult stem cells must be fused with embryonic
cells.
C) Cytoplasm from embryonic cells is injected into the
adult cells.
D) An adenovirus vector is used to transfer embryonic
gene products into adult cells.
E) The nucleus of an embryonic cell is used to replace the
nucleus of an adult cell.
Answer: A
42) Let us suppose that someone is successful at
producing induced pluripotent stem cells (iPS) for replacement of pancreatic
insulin-producing cells for people with type 1 diabetes. Which of the following
could still be problems?
I. the possibility that, once introduced into the
patient, the iPS cells produce nonpancreatic cells
II. the failure of the iPS cells to take up residence in
the pancreas
III. the inability of the iPS cells to respond to
appropriate regulatory signals
A) I only
B) II only
C) III only
D) I and II
E) all of them
Answer: E
43) Genetic engineering is being used by the
pharmaceutical industry. Which of the following is not currently one of the
uses?
A) production of human insulin
B) production of human growth hormone
C) production of tissue plasminogen activator
D) genetic modification of plants to produce vaccines
E) creation of products that will remove poisons from the
human body
Answer: E
44) Genetically engineered plants
A) are more difficult to engineer than animals.
B) include a transgenic rice plant that can help prevent
vitamin A deficiency.
C) are being rapidly developed, but traditional plant breeding
programs are still the only method used to develop new plants.
D) are able to fix nitrogen themselves.
E) are banned throughout the world.
Answer: B
45) Scientists developed a set of guidelines to address
the safety of DNA technology. Which of the following is one of the adopted
safety measures?
A) Microorganisms used in recombinant DNA experiments are
genetically crippled to ensure that they cannot survive outside of the
laboratory.
B) Genetically modified organisms are not allowed to be
part of our food supply.
C) Transgenic plants are engineered so that the plant
genes cannot hybridize.
D) Experiments involving HIV or other potentially
dangerous viruses have been banned.
E) Recombinant plasmids cannot be replicated.
Answer: A
46) One successful form of gene therapy has involved
delivery of an allele for the enzyme adenosine deaminase (ADA) to bone marrow
cells of a child with SCID, and delivery of these engineered cells back to the
bone marrow of the affected child. What is one major reason for the success of
this procedure as opposed to many other efforts at gene therapy?
A) The engineered bone marrow cells from this patient can
be used for any other SCID patient.
B) The ADA-introduced allele causes all other
ADA-negative cells to die.
C) The engineered cells, when reintroduced into the
patient, find their way back to the bone marrow.
D) No vector is required to introduce the allele into
ADA-negative cells.
E) The immune system fails to recognize cells with the
variant gene.
Answer: C
47) Which of the following is one of the technical
reasons why gene therapy is problematic?
A) Most cells with an engineered gene do not produce gene
product.
B) Most cells with engineered genes overwhelm other cells
in a tissue.
C) Cells with transferred genes are unlikely to
replicate.
D) Transferred genes may not have appropriately
controlled activity.
E) mRNA from transferred genes cannot be translated.
Answer: D
48) As genetic technology makes testing for a wide
variety of genotypes possible, Which of the following is likely to be an
increasingly troublesome issue?
A) use of genotype information to provide positive
identification of criminals
B) using technology to identify genes that cause criminal
behaviors
C) the need to legislate for the protection of the
privacy of genetic information
D) discrimination against certain racial groups because
of major genetic differences
E) alteration of human phenotypes to prevent early
disease
Answer: C
49) Which enzyme was used to produce the molecule in
Figure ?
A) ligase
B) transcriptase
C) a restriction enzyme
D) RNA polymerase
E) DNA polymerase
Answer: C
50) The segment of DNA shown in Figure 20.2 has
restriction sites I and II, which create restriction fragments A, B, and C.
Which of the gels produced by electrophoresis shown below best represents the
separation and identity of these fragments?
A. A
B. B
C. C
D. D
E. E
Answer: B
51. The DNA profiles that follow represent four different
individuals.
Which of the following statements is consistent with
the results?
A) B is the child of A and C.
B) C is the child of A and B.
C) D is the child of B and C.
D) A is the child of B and C.
E) A is the child of C and D.
Answer: B
52) Which of the following statements is most likely
true?
A) D is the child of A and C.
B) D is the child of A and B.
C) D is the child of B and C.
D) A is the child of C and D.
E) B is the child of A and C.
Answer: B
53) Which of the following are probably siblings?
A) A and B
B) A and C
C) A and D
D) C and D
E) B and D
Answer: D
54. A eukaryotic gene has "sticky ends" produced by
the restriction endonuclease EcoRI. The gene is added to a mixture containing
EcoRI and a bacterial plasmid that carries two genes conferring resistance to
ampicillin and tetracycline. The plasmid has one recognition site for EcoRI
located in the tetracycline resistance gene. This mixture is incubated for
several hours, exposed to DNA ligase, and then added to bacteria growing in
nutrient broth. The bacteria are allowed to grow overnight and are streaked on
a plate using a technique that produces isolated colonies that are clones of
the original. Samples of these colonies are then grown in four different media:
nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient
broth plus ampicillin and tetracycline, and nutrient broth without antibiotics.
Bacteria that contain the plasmid, but not the
eukaryotic gene, would grow
A) in the nutrient broth plus ampicillin, but not in the
broth containing tetracycline.
B) only in the broth containing both antibiotics.
C) in the broth containing tetracycline, but not in the
broth containing ampicillin.
D) in all four types of broth.
E) in the nutrient broth without antibiotics only.
Answer: D
55. A eukaryotic gene has "sticky ends" produced by
the restriction endonuclease EcoRI. The gene is added to a mixture containing
EcoRI and a bacterial plasmid that carries two genes conferring resistance to
ampicillin and tetracycline. The plasmid has one recognition site for EcoRI
located in the tetracycline resistance gene. This mixture is incubated for
several hours, exposed to DNA ligase, and then added to bacteria growing in
nutrient broth. The bacteria are allowed to grow overnight and are streaked on a
plate using a technique that produces isolated colonies that are clones of the
original. Samples of these colonies are then grown in four different media:
nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient
broth plus ampicillin and tetracycline, and nutrient broth without antibiotics.
Bacteria containing a plasmid into which the
eukaryotic gene has integrated would grow in
A) the nutrient broth only.
B) the nutrient broth and the tetracycline broth only.
C) the nutrient broth, the ampicillin broth, and the
tetracycline broth.
D) all four types of broth.
E) the ampicillin broth and the nutrient broth.
Answer: E
56. A eukaryotic gene has "sticky ends" produced by
the restriction endonuclease EcoRI. The gene is added to a mixture containing
EcoRI and a bacterial plasmid that carries two genes conferring resistance to
ampicillin and tetracycline. The plasmid has one recognition site for EcoRI
located in the tetracycline resistance gene. This mixture is incubated for
several hours, exposed to DNA ligase, and then added to bacteria growing in
nutrient broth. The bacteria are allowed to grow overnight and are streaked on
a plate using a technique that produces isolated colonies that are clones of
the original. Samples of these colonies are then grown in four different media:
nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient
broth plus ampicillin and tetracycline, and nutrient broth without antibiotics.
Bacteria that do not take up any plasmids would grow
on which media?
A) the nutrient broth only
B) the nutrient broth and the tetracycline broth
C) the nutrient broth and the ampicillin broth
D) the tetracycline broth and the ampicillin broth
E) all three broths
Answer: A
57. A group of six students has taken samples of their own
cheek cells, purified the DNA, and used a restriction enzyme known to cut at
zero, one, or two sites in a particular gene of interest.
Why might they be conducting such an experiment?
A) to find the location of this gene in the human genome
B) to prepare to isolate the chromosome on which the gene
of interest is found
C) to find which of the students has which alleles
D) to collect population data that can be used to assess
natural selection
E) to collect population data that can be used to study
genetic drift
Answer: C
58. A group of six students has taken samples of their own
cheek cells, purified the DNA, and used a restriction enzyme known to cut at
zero, one, or two sites in a particular gene of interest.
Their next two steps, in order, should be
A) use of a fluorescent probe for the gene sequence, then
electrophoresis.
B) electrophoresis of the fragments followed by
autoradiography.
C) electrophoresis of the fragments, followed by the use
of a probe.
D) use of a ligase that will anneal the pieces, followed
by Southern blotting.
E) use of reverse transcriptase to make cDNA, followed by
electrophoresis.
Answer: C
A group of six students has taken samples of their own
cheek cells, purified the DNA, and used a restriction enzyme known to cut at
zero, one, or two sites in a particular gene of interest.
59) Analysis of the data obtained shows that two students
each have two fragments, two students each have three fragments, and two
students each have one only. What does this demonstrate?
A) Each pair of students has a different gene for this
function.
B) The two students who have two fragments have one
restriction site in this region.
C) The two students who have two fragments have two
restriction sites within this gene.
D) The students with three fragments are said to have
"fragile sites."
E) Each of these students is heterozygous for this gene.
Answer: B
60. CML (chronic myelogenous leukemia) results from a
translocation between human chromosomes 9 and 22. The resulting chromosome 22
is significantly shorter than usual, and it is known as a Philadelphia (Ph')
chromosome. The junction at the site of the translocation causes overexpression
of a thymine kinase receptor. A new drug (Gleevec or imatinib) has been found
to inhibit the disease if the patient is treated early.
Which of the following would be a reasonably
efficient technique for confirming the diagnosis of CML?
A) searching for the number of telomeric sequences on
chromosome 22
B) looking for a Ph' chromosome in a peripheral blood
smear
C) enzyme assay for thymine kinase activity
D) FISH study to determine the chromosomal location of
all chromosome 22 fragments
E) identification of the disease phenotype in review of
the patient's records
Answer: D
61. CML (chronic myelogenous leukemia) results from a
translocation between human chromosomes 9 and 22. The resulting chromosome 22
is significantly shorter than usual, and it is known as a Philadelphia (Ph')
chromosome. The junction at the site of the translocation causes overexpression
of a thymine kinase receptor. A new drug (Gleevec or imatinib) has been found
to inhibit the disease if the patient is treated early.
Why would Gleevec most probably cause remission of
the disease?
A) It reverses the chromosomal translocation.
B) It eliminates the Ph' chromosome.
C) It removes Ph'-containing progenitor cells.
D) The drug inhibits the replication of the affected
chromosome.
E) The drug inhibits the specific thymine kinase
receptor.
Answer: E
62. CML (chronic myelogenous leukemia) results from a
translocation between human chromosomes 9 and 22. The resulting chromosome 22
is significantly shorter than usual, and it is known as a Philadelphia (Ph')
chromosome. The junction at the site of the translocation causes overexpression
of a thymine kinase receptor. A new drug (Gleevec or imatinib) has been found
to inhibit the disease if the patient is treated early.
One possible use of transgenic plants is in the
production of human proteins, such as vaccines. Which of the following is a
possible hindrance that must be overcome?
A) prevention of transmission of plant allergens to the
vaccine recipients
B) prevention of vaccine-containing plants being consumed
by insects
C) use of plant cells to translate non-plant-derived mRNA
D) inability of the human digestive system to accept
plant-derived protein
E) the need to cook all such plants before consuming them
Answer: A
63. Pharmacogenetics is an increasingly important discipline
that uses genetic information to tailor the prescription of drug treatments to
individuals. In the case of chemotherapy for breast cancer, for example,
different patients need and/or respond to different treatments.
Patients whose tumors are HER-2 positive respond to
herceptin whereas other patients do not. Patients whose tumors have estrogen
receptors will be best served if
A) their estrogen receptors are blocked by using RNAi.
B) their estrogen release is activated and/or elevated.
C) the estrogen receptors are blocked by other molecules
that can use the same receptors.
D) they are given herceptin as well as estrogen.
E) they are given a complete hysterectomy.
Answer: C
64. Pharmacogenetics is an increasingly important discipline
that uses genetic information to tailor the prescription of drug treatments to
individuals. In the case of chemotherapy for breast cancer, for example,
different patients need and/or respond to different treatments.
Breast tumor biopsy specimens can be typed for a
number of gene expression patterns. Together, these can provide risk analysis
for the likely aggressive growth and metastasis of the tumor. How can this most
help the physician and patient?
A) Some patients want to know as much as possible.
B) This can help them to decide whether and what kind of
chemotherapy is warranted.
C) This can help them decide whether the tumor should be
removed.
D) Some physicians may use the information to decide what
to do, but not tell the patient.
E) This can help to aggregate health statistics.
Answer: B
65) Which of the following tools of recombinant DNA
technology is incorrectly paired with its use?
A) restriction enzymeanalysis of
RFLPs
B) DNA ligasecutting DNA,
creating sticky ends of restriction fragments
) DNA polymerasepolymerase chain
reaction to amplify sections of DNA
D) reverse transcriptaseproduction
of cDNA from mRNA
E) electrophoresisseparation of
DNA fragments
Answer: B
66) 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.
Answer: C
67) A paleontologist has recovered a bit of tissue from
the 400-year-old preserved skin of an extinct dodo (a bird). To compare a
specific region of the 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 blotting
Answer: B
68) DNA technology has many medical applications. Which
of the following is not done routinely at present?
A) production of hormones for treating diabetes and
dwarfism
B) production of microbes that can metabolize toxins
C) introduction of genetically engineered genes into
human gametes
D) prenatal identification of genetic disease alleles
E) genetic testing for carriers of harmful alleles
Answer: C
69) In recombinant DNA methods, the term vector can refer
to
A) the enzyme that cuts DNA into restriction fragments.
B) the sticky end of a DNA fragment.
C) a SNP marker.
D) a plasmid used to transfer DNA into a living cell.
E) a DNA probe used to identify a particular gene.
Answer: D
70) Which of the following would not be true of cDNA
produced using human brain tissue as the starting material?
A) It could be amplified by the polymerase chain
reaction.
B) It could be used to create a complete genomic library.
C) It was produced from mRNA using reverse transcriptase.
D) It could be used as a probe to detect genes expressed
in the brain.
E) It lacks the introns of the human genes.
Answer: B
71) Expression of a cloned eukaryotic gene in a bacterial
cell involves many challenges. 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.
Answer: A
72) Which of the following sequences in double-stranded
DNA is most likely to be recognized as a cutting site for a restriction enzyme?
A) AAGG
TTCC
B) AGTC
TCAG
C) GGCC
CCGG
D) ACCA
TGGT
E) AAAA
TTTT
Answer: C
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