Campbell Biology Chapter 20 (powell_h)
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 20.1?
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? SEE IMAGE FOR FIGURE
A. SEE IMAGE
B. SEE IMAGE
C. SEE IMAGE
D. SEE IMAGE
E. SEE IMAGE
Answer: B
The DNA profiles that follow represent four different individuals.
51) 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
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.
54) 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
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.
55) 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
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.
56) 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
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.
57)
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
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.
58)
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
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.
60) 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
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.
61) 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
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.
62) 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
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.
63) 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
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.
64) 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
C) 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