front 1 The tryptophan operon is a repressible operon that is
- permanently turned
on
- turned on only when tryptophan is present in the growth
medium
- turned off only when glucose is present in the growth
medium
- turned on only when glucose is present in the growth
medium
- turned off whenever tryptophan is added to the growth
medium
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front 2 Which of the following, when taken up by the cell, binds to the
repressor so that the repressor no longer binds to the operator?
- ubiquitin
- inducer
- promoter
- repressor
- corepressor
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front 3 The lactose operon is likely to be transcribed when
- there is more glucose in
the cell than lactose
- the lactose levels within the cell is
low
- there is glucose but no lactose in the cell
- the
lactose level is high within the cell
- the oxygen level is
high and the lactose level is low
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front 4 For a repressible operon to be transcribed, which of the following
must occur?
- a corepressor must be
present
- RNA polymerase and the active repressor must be
present
- RNA polymerase must bind to the promoter, and the
repressor must be inactive
- RNA polymerase cannot be
present, and the repressor must be inactive
- RNA polymerase
must no occupy the promoter, and the repressor must be
inactive.
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front 5 In eukaryotes, general transcription factors
- are required for the
expression of specific protein-encoding genes
- bind to other
proteins or to a sequence element within the promoter called the
TATA box
- inhibit RNA polymerase binding to the promoter and
begin transcribing
- usually lead to a high level of
transcription even without additional specific transcription
factors
- bind to sequences just after the start site of
transcription
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front 6 Two potential devices that eukaryotic cells use to regulate
transcription are
- DNA methylation and
histone amplification
- DNA amplification and histone
methylation
- DNA acetylation and methylation
- DNA
methylation and histone modification
- histone amplification
and DNA acetylation
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front 7 The questions below refer to the following terms. Each term may be
used once, more than once, or not at all.
- inducer
- promoter
- RNA polymerase
- repressor
- operator
RNA polymerase binds to this region to initiate transcription | |
front 8 The questions below refer to the following terms. Each term may be
used once, more than once, or not at all.
- inducer
- promoter
- RNA polymerase
- repressor
- operator
Can inhibit transcription by blocking the binding of positively
acting transcription factors to the DNA | |
front 9 The questions below refer to the following terms. Each term may be
used once, more than once, or not at all.
- inducer
- promoter
- RNA polymerase
- repressor
- operator
Region between the promoter and the first gene which acts as an
"on-off switch." | |
front 10 The questions below refer to the following terms. Each term may be
used once, more than once, or not at all.
- inducer
- promoter
- RNA polymerase
- repressor
- operator
Product of the regulatory gene | |
front 11 The host range of a virus is determined by
- the enzymes carried by
the virus
- whether its nucleic acid is DNA or RNA
- the proteins in the host's cytoplasm
- the enzymes
produced by the virus before it infects the cell
- the
proteins on its surface and that of the host
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front 12 Which of the following is characteristic of the lytic cycle?
- many bacterial cells
containing viral DNA are produced
- viral DNA is incorporated
into the host genome
- the viral genome replicates without
destroying the host
- a large number of phages are released
at a time
- the virus-host relationship lasts for
generations
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front 13 Which of the following statements describes the lysogenic cycle of
lambda (λ) phage?
- after infection, the
viral genes immediately turn the host cell into a lambda-producing
factory, and the host cell then lyses
- most of the prophage
genes are activated by the product of a particular prophage
gene
- the phage genome replicates along with the host
genome
- certain environmental triggers can cause the phage to
exit the host genome, switching from the lytic to the lysogenic
- the phage DNA is incorporated by crossing over into any
nonspecific site on the host cell's DNA
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front 14 Which of the three types of viruses shown above would you expect to
include glycoproteins?
- I only
- II
only
- III only
- I and II only
- all three
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front 15 Viruses that infect bacteria are referred to as
- viralcidens
- bacteriocidins
- bacterialogens
- bacteriophages
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front 16 All viruses possess
- a capsid and an
envelope
- DNA as well as RNA
- a genome and a
capsid
- a nucleocapsid and envelope
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front 17 In the figure, when new viruses are being assembled (IV), what
mediates the assembly?
- host cell
chaperones
- assembly proteins coded for by the host
nucleus
- assembly proteins coded for by the viral genes
- viral RNA intermediates
- nothing; they
self-assemble
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front 18 As an embryo develops, new cells are produced as the result of
- differentiation
- preformation
- cell division
- morphogenesis
- epigenesis
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front 19 Fertilization normally
- reinstates diploidy
- follows gastrulation
- is required for
parthenogensis
- merges two diploid cells into one haploid
cell
- precedes ovulation
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front 20 Cells move to new positions as an embryo establishes its three germ
tissue layers during
- determination
- cleavage
- fertilization
- induction
- gastrulation
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front 21 What is the most logical sequence of steps for splicing foreign DNA
into a plasmid and inserting the plasmid into a bacterium?
- transform bacteria with
a recombinant DNA molecule
- cut the plasmid DNA using
restriction enzymes (endonuclease)
- extract plasmid DNA from
bacterial cells
- hydrogen-bond the plasmid DNA to nonplasmid
DNA fragments
- use ligase to seal plasmid DNA to nonplasmid
DNA
- II, III, V, IV, I
- III, II, IV, V, I
- III, IV, V, I, II
- IV, V, I,
II, III
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front 22 Which of the following uses labeled probes to visualize the
expression of genes in whole tissues and organisms?
- RT-PCR
- in situ
hybridization
- DNA microarrays
- RNA interference
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front 23 Which of the following is used to make complementary DNA (cDNA) from RNA?
- restriction enzymes
- gene cloning
- DNA ligase
- gel
electrophoresis
- reverse transcriptase
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front 24 The reason for using Taq polymerase for PCR is that
- it is heat stable and
can withstand the temperature changes of the cycler
- only
minute amounts are needed for each cycle of PCR
- it binds
more readily than other polymerases to primer
- it has
regions that are complementary to primers
- all of these are
correct
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front 25 DNA microarrays have made a huge impact on genomic studies because they
- can be used to eliminate
the function of any gene in the genome
- can be used to
introduce entire genomes into bacterial cells
- allow the
expression of many or even all of the genes in the genome to be
compared at once
- allow physical maps of the genome to be
assembled in a very short time
- dramatically enhance the
efficiency of restriction enzymes
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front 26 Which of the following describes the transfer of polypeptide
sequences to a membrane to analyze gene expression?
- southern blotting
- northern blotting
- western blotting
- eastern
blotting
- RT-PCR
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front 27 Which enzyme was used to produce the molecule in the figure above?
- ligase
- a
restriction enzyme (endonuclease)
- RNA polymerase
- DNA polymerase
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front 28 In 1997, Dolly the sheep was cloned. Which of the following processes
was used?
- replication and
dedifferentiation of adult stem cells from sheep bone marrow
- separation of an early stage blastula into separate cells, one
of which was incubated in a surrogate ewe
- fusion of an
adult cell's nucleus with an enucleated sheep egg, followed by
incubation in a surrogate
- isolation of stem cells from a
lamb embryo and production of a zygote equivalent
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front 29 Which of the following is in the correct order for one cycle of
polymerase chain reaction (PCR)?
- denature DNA; add fresh
enzyme; anneal primers; add dNTPs; extend primers
- anneal
primers; denature DNA; extend primers
- extend primers;
anneal primers; denature DNA
- denature DNA; anneal primers;
extend primers
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front 30 Genetically engineered plants ___
- are more difficult to
develop than genetically engineered animals
- include
transgenic rice plants that can grow in water of high salinity
- are used in research but not yet in commercial agricultural
production
- are banned throughout the world
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front 31 Scientists developed a set of guidelines to address the safety of DNA
technology. Which of the following is one of the adopted safety measure?
- microorganisms used in
recombinant DNA experiments are genetically crippled to ensure that
they cannot survive outside of the laboratory
- genetically
modified organisms are not allowed to be part of our food
supply
- transgenic plants are engineered so that the plant
genes cannot hybridize
- experiments involving HIV or other
potentially dangerous viruses have been banned
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front 32 Plasmids are used as vectors in plant and bacterial genetic
engineering. However, there is a major difference in the fate of genes
introduced into bacteria on most bacterial plasmids and into plants on
tumor-inducing (Ti) plasmids. What is this difference?
- in bacteria genes are
stably expressed; in plants, gene expression is always lost
quickly
- gene expression tends to decrease rapidly and
unpredictably in bacteria; gene expression is much more stable in
plants
- bacterial plasmids are circular DNAs; Ti plasmid DNA
is linear
- bacterial plasmids and the genes they carry
usually are not integrated into the chromosome; Ti plasmids and the
genes they carry are integrated into the chromosome
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front 33 The segment of DNA shown in the figure above 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, B, C
- C, A,
B
- B, A, C
- C, A, B
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front 34 In a hypothetical situation, the genes for sex pills construction and
for tetracycline resistance are located together on the same plasmid
within a particular bacterium. If this bacterium readily performs
conjugation involving a copy of this plasmid, then the result should be
- a bacterium that has
undergone transduction
- the rapid spread of tetracycline
resistance to other bacteria in that habitat
- the subsequent
loss of tetracycline resistance from this bacterium
- the
production of endospores among the bacterium's progeny
- the
temporary possession by this bacterium of a completely diploid
gene
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front 35 Which of these statements about prokaryotes is correct?
- bacterial cells
conjugate to mutually exchange genetic material
- their
genetic material is confined within vesicles known as plasmids
- they divide by binary fission, without mitosis or meiosis
- the persistence of bacteria throughout evolutionary time is due
to their genetic homogeneity (in other words, sameness..)
- genetic variation in bacteria is not known to occur, because of
their asexual mode of reproduction
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front 36 An R plasmid encodes
- antibiotics resistance
in bacteria
- rates of metabolic pathways
- repressor
for gene expression
- regulation of an operon
- reverse transcriptase in HIV
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front 37 In Fred Griffith's experiments, harmless R strain pneumococcus became
lethal S strain pneumococcus as the result of which of the following?
- horizontal gene transfer
- transduction
- conjugation
- transformation
- genetic
recombination
- 2 only
- 4
only
- 2 and 5
- 1, 3, and 5
- 1, 4, and 5
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front 38 Use the following answers for the following questions. The answers
may be used once, more than once, or not at all.
- transduction
- transposition
- translation
- transformation
- conjugation
External DNA is taken up by a cell | |
front 39 Use the following answers for the following questions. The answers
may be used once, more than once, or not at all.
- transduction
- transposition
- translation
- transformation
- conjugation
DNA is transferred from one bacterium to another by bacteriophage | |
front 40 Use the following answers for the following questions. The answers
may be used once, more than once, or not at all.
- transduction
- transposition
- translation
- transformation
- conjugation
A plasmid is exchanged between bacteria through a pilus | |
front 41 In which feature(s) should one be able to locate a complete
chromosome of a bacterium?
- nucleolus
- prophage
- endospore
- nucleoid
- 4 only
- 1 and
3
- 3 and 4
- 2 and 3
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front 42 From earliest to latest, the overall sequence of early development
proceeds in which of the following sequences?
- first cell division
--> synthesis of embryo's DNA begins --> acrosomal reaction
--> cortical reaction
- cortical reaction --> synthesis
of embryo's DNA begins -> acrosomal reaction --> first cell
division
- cortical reaction --> acrosomal reaction -->
first cell division --> synthesis of embryo's DNA begins
- acrosomal reaction --> cortical reaction --> synthesis of
embryo's DNA begins --> first cell division
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front 43 Which of the following are characteristic of the lytic cycle and
lysogenic cycle respectively?
- Lytic: viral DNA is
incorporated into the host genome. Lysogenic: kills the host cell
and many are released
- Lytic: the viral genome replicates
without destroying the host. Lysogenic: kills the host cell and many
are released.
- Lytic: a large number of phages are released
at a time by budding. Lysogenic: after infection, the viral genes
immediately turn the host cell into a lambda-producing factory,
doing which the host cell lyses and dies.
- Lytic: a large
number of phages are released at a time by killing the host cell.
Lysogenic: the phage genome replicates along with the host genome
and can switch to lytic form when conditions are not favorable.
- I
- II
- IV
- III
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front 44 Which statements regarding the lac and trp operons
are correct?
- The lac operon is
repressible because its default is "on." This means that
its genes are almost always being expressed.
- The lac operon
is inducible, and the trp operon is repressible.
- The trp
operon is repressible because its default is "on." This
means that its genes are almost always being expressed.
- The
inducible operon is turned on by the presence of the end product,
and the repressible operon is turned off by the presence of the
substrate.
- The signal molecule (i.e. the molecule that binds
to the repressor) for the trp operon is tryptophan, and the signal
molecule for the lac operon is allolactose.
- The signal
molecule (i.e. the molecule that binds to the repressor) for the trp
operon is tryptophan, and the signal molecule for the lac operon is
lactose.
- The inducible operon is turned on by the presence of
substrate (allolactose), and the repressible operon is turned off by
the presence of the end product (tryptophan)
- V, VI, VII, VIII
- I, IV, VI, VII
- I, III, IV, VI
- II, III, IV,
VI
- II, III, V, VIII
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front 45 What are the main ways that a bacterium can gain new DNA?
- Conjugation in which a
plasmid is exchanged between bacteria through a pilus
- Transformation, in which a plasmid is exchanged between bacteria
through a pilus
- Transformation, during which DNA is
assimilated from the surrounding environment by a
bacterium/cell
- Transduction, during which DNA is assimilated
from the surrounding environment by a bacterium/cell
- Transduction, in which DNA is transferred from one bacterium to
another by a virus
- Conjugation, in which DNA is transferred
from one bacterium to another by a virus
- II, V, VI
- I,
III, V
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