4321741
Descripción
Test por Nadia Siddique, actualizado hace más de 1 año
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Creado por Nadia Siddique
hace casi 9 años
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|
Pregunta 1
Pregunta
The first step in the polymerase chain reaction (PCR) is
Respuesta
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Denaturation
-
Cooling
-
Annealing
-
Primer extension
Pregunta 2
Pregunta
In a polymerase chain reaction, a synthetic sequence of nucleotides are involved in
Respuesta
-
Denaturing
-
Heating
-
Cooling
-
Copying
-
All of the above
Pregunta 3
Pregunta
Bacteria protect themselves from viruses by fragmenting viral DNA upon entry with
Respuesta
-
Ligases
-
Endonucleases
-
Methylases
-
Vectors
-
Probes
Pregunta 4
Pregunta
When "sticky ends" are paired, they can be joined by
Respuesta
-
Restriction Enzymes
-
pSC101
-
Methylases
-
X-gal
-
DNA ligase
Pregunta 5
Pregunta
One of the most useful methods for identifying a specific gene is
Respuesta
-
Western blot
-
Southern blot
-
Eastern blot
-
Magnetic resonance imaging
-
Thin chromatography
Pregunta 6
Pregunta
The Polymerase Chain Reaction is used to:
Respuesta
-
amplify a small amount of DNA
-
cleave bacterial plasmids
-
seal "sticky ends"
-
identify target plasmids
-
none of the above
Pregunta 7
Pregunta
When tryptophan is present in the medium, the transcription of tryptophan producing genes in E. coli is stopped by a helix-turn-helix regulator binding to the
Respuesta
-
trp repressor
-
trp operon
-
trp promoter
-
trp operator
-
trp polymerase
Pregunta 8
Pregunta
When tryptophan is present in the environment of E. coli, the tryptophan binds to the
Respuesta
-
trp operon
-
trp promoter
-
trp operator
-
trp repressor
-
trp polymerase
Pregunta 9
Pregunta
The operon that controls tryptophan producing genes in E. coli consists of _______________
Respuesta
-
activator
-
regulator
-
promoter
-
operator
-
repressor
Pregunta 10
Pregunta
In order for a gene to be transcribed, RNA polymerase must have access to the DNA helix and be able to bind to the genes
Respuesta
-
activator
-
regulator
-
promoter
-
operator
-
repressor
Pregunta 11
Pregunta
In the function of the lac operon in E. coli, the lac genes are transcribed in the presence of lactose because
Respuesta
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RNA polymerase binds to the operator
-
the repressor cannot bind to the promoter
-
an isomer of lactose binds to the repressor
-
CAP does not bind to the operator
-
of the absence of cAMP
Pregunta 12
Pregunta
The role of methylation of DNA is now viewed as
Respuesta
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interfering with DNA transcription by blocking base pairing between cytosine and guanine
-
complexing with enhancers to prevent transcription
-
prevention of mutation
-
insuring that genes that are turned off, stay off
-
irrelevant to gene transcription
Pregunta 13
Pregunta
E. coli is able to use foods other than glucose in the absence of available glucose, because falling levels of glucose cause an increase of
Respuesta
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cAMP
-
CAP
-
lactase
-
glu operon
-
tRNA
Pregunta 14
Pregunta
In the absence of glucose, E. coli can import lactose to change into glucose and galactose because CAP binds to the
Respuesta
-
cAMP
-
DNA
-
lac operon
-
operator
-
repressor
Pregunta 15
Pregunta
Which is not part of the lac operon?
Respuesta
-
repressor
-
activator protein
-
operator
-
promoter
-
structural gene
Pregunta 16
Pregunta
In an operon the location of the regulatory region occurs ________ the structural genes.
Respuesta
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after
-
within
-
before
Pregunta 17
Pregunta
Which of the following is part of an operon?
Respuesta
-
structural genes
-
operator
-
promoter
-
a CAP binding site
-
all of the above
Pregunta 18
Pregunta
Transcription is initiated when RNA polymerase binds to
Respuesta
-
promoter
-
initiator
-
codon
-
transcriptor
Pregunta 19
Pregunta
In eukaryotes, there are _______________ codons that specify amino acids
Respuesta
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21
-
24
-
61
-
64
-
100
Pregunta 20
Pregunta
In eukaryotes, the "start" codon also specifies the amino acid,
Respuesta
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phenylalanine
-
valine
-
methionine
-
aspartate
Pregunta 21
Pregunta
In transcription, the nucleotide sequence CAT in DNA would specify _______________ in mRNA.
Respuesta
-
TAC
-
GAU
-
CAT
-
GTU
-
GUA
Pregunta 22
Pregunta
The genetic code consists of groups of three nucleotides called
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-
codons
-
introns
-
anticodons
-
reading frame
-
triplets
Pregunta 23
Pregunta
The function of tRNA is to
Respuesta
-
provide a site for polypeptide synthesis
-
transport amino acids to the ribosome
-
travel to the ribosome to direct the assembly of polypeptides
-
transcribe DNA
-
translate DNA
Pregunta 24
Pregunta
In the formation of an initiation complex, a _______________ is positioned first.
Respuesta
-
met-tRNA
-
ser-tRNA
-
tyr-rRNA
-
mval-tRNA
-
cyst-tRNA
Pregunta 25
Pregunta
The function of mRNA is to
Respuesta
-
provide a site for polypeptide synthesis
-
transport amino acids to the ribosome
-
travel to the ribosome to direct the assembly of polypeptides
-
transcribe DNA
-
translate DNA
Pregunta 26
Pregunta
The process of _______________ cuts introns from the primary transcript and the final "processed" mRNA is produced.
Respuesta
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RNA cleaving
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RNA translocation
-
RNA splicing
-
RNA elongation
-
RNA releasing
Pregunta 27
Pregunta
In the process of translation,
Respuesta
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a strand of mRNA is formed with nucleotide sequences complementary to those of DNA
-
nucleotide sequences of tRNA are established
-
a polypeptide is formed in response to the rRNA nucleotide sequence
-
rRNA is synthesized with sequences complementary to those of tRNA
-
a polypeptide is formed as dictated by the nucleotide sequence in mRNA
Pregunta 28
Pregunta
In mRNA, the series of nucleotides CCC specifies
Respuesta
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serine
-
proline
-
alanine
-
arginine
-
stop
Pregunta 29
Pregunta
A molecule of tRNA with the anticodon AAA will transport the amino acid
Respuesta
-
phenylalanine
-
lysine
-
glycine
-
leucine
-
alanine
Pregunta 30
Pregunta
As polypeptides are formed at the ribosome, elongation continues until _______________ is exposed.
Respuesta
-
a release factor
-
an intron
-
a nonsense codon
-
an exon
-
polypeptidases
Pregunta 31
Pregunta
Which one of the following is not a kind of RNA?
Respuesta
-
mRNA
-
tRNA
-
rRNA
-
nRNA
-
All of the above are kinds of RNA
Pregunta 32
Pregunta
The direct result of transcription is
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-
a duplicate DNA molecule
-
nRNA
-
protein
-
mRNA
-
none of the above
Pregunta 33
Pregunta
The direct result of translation is
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-
duplicate DNA
-
mRNA
-
protein
-
nRNA (nuclear RNA)
-
none of the above
Pregunta 34
Pregunta
Which one of the following is not associated with transcription?
Respuesta
-
tRNA
-
mRNA
-
nRNA
-
rRNA
-
all of the above
Pregunta 35
Pregunta
Which one of the following is not associated with translation?
Respuesta
-
tRNA
-
mRNA
-
rRNA
-
anticodons
-
All are involved with translation
Pregunta 36
Pregunta
According to Chargaff's rule, the following proportion exists in DNA
Respuesta
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A=G
-
C=G
-
T=G
-
A>T
-
C>G
Pregunta 37
Pregunta
The actual synthesis of DNA in E. coli is the function of
Respuesta
-
polymerase I
-
primase
-
primer
-
polymerase III
-
ligase
Pregunta 38
Pregunta
Since the first nucleotides cannot be linked in a newly synthesized strand in DNA replication, ___________ is required.
Respuesta
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DNA primer
-
DNA ligase
-
DNA polymerase
-
RNA primer
-
helicase
Pregunta 39
Pregunta
The fact that some viruses use DNA to direct their heredity was demonstrated by
Respuesta
-
finding radioactive sulfur from a bacteriophage in a bacterium
-
finding radioactive phosphorus from a bacterium in a bacteriophage
-
finding that radioactive phosphorus from a bacteriophage had mutated in bacterium
-
finding radioactive phosphorus from a bacteriophage in a bacterium
-
finding radioactive sulfur from a bacterium in a bacteriophage
Pregunta 40
Pregunta
Okazaki fragments are used to elongate
Respuesta
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the leading strand toward the replication fork
-
the lagging strand toward the replication fork
-
both strands in both directions
-
the leading strand away from the replication fork
-
the lagging strand away from the replication fork
Pregunta 41
Pregunta
In nucleic acids, the free hydroxyl group is attached to the _______________ carbon of the sugar.
Respuesta
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5'
-
4'
-
3'
-
2'
-
1'
Pregunta 42
Pregunta
A single enzyme is specified by a single
Respuesta
-
gene
-
chromosome
-
nucleosome
-
nucleotide
-
histone
Pregunta 43
Pregunta
In replication of DNA, the helix is opened and untwisted by
Respuesta
-
ribase
-
primase
-
deoxase
-
helicase
-
ligase
Pregunta 44
Pregunta
_______________ join DNA fragments to the lagging strand
Respuesta
-
telomeres
-
centromeres
-
helicases
-
ligases
-
polymerases
Pregunta 45
Pregunta
Which statement about the elongation of the lagging strand during DNA replication is correct?
Respuesta
-
It is synthesized in a 3' --> 5' direction.
-
It progresses (grows) toward the replication fork
-
It requires a short RNA primer to proceed.
-
It is synthesized by DNA ligase
-
It is synthesized continuously
Pregunta 46
Pregunta
If one side of a DNA molecule contains the following sequence of nucleotides, AGTCCG, the complementary sequence on the other side would be:
Respuesta
-
GCCTGA
-
AGTCCG
-
TCAGGC
-
CTGAAT
-
none of the above
Pregunta 47
Pregunta
During your summer job at Virotech, you isolate a previously unknown virus. Analysis of its genome reveals that it is composed of a double stranded DNA molecule containing 14% T (thymine). Based on this information, what would you predict the %C (cytosine) to be?
Respuesta
-
14%
-
28%
-
36%
-
72%
-
can't tell!
Pregunta 48
Pregunta
The process of acquiring a gene from another organism is called transformation.
Respuesta
- True
- False
Pregunta 49
Pregunta
The Hershey-Chase experiment showed that the virus protein is responsible for directing the production of new viruses.
Respuesta
- True
- False
Pregunta 50
Pregunta
The two sides of the double helix structure of DNA are held together with hydrogen bonds.
Respuesta
- True
- False
Pregunta 51
Pregunta
DNA replication is called semiconservative because half of each of the two new strands of DNA is "old" DNA from the original DNA molecule and half is "new" DNA.
Respuesta
- True
- False
Pregunta 52
Pregunta
Genetic engineering has been used to do all of the following except:
Respuesta
-
make plants more resistant to frost
-
make plants more resistant to disease
-
make plants more resistant to herbicides
-
improve the nutritional balance of plants
-
all of the above
Pregunta 53
Pregunta
According to Mendel, which of the following cause an organism's size, colour and markings?
Respuesta
-
Chromosomes
-
Genes
-
Alleles
-
Factors
Pregunta 54
Pregunta
Which term is associated with eukaryotic DNA?
Respuesta
-
chrosome
-
histone
-
telomere
-
all of the above
Pregunta 55
Pregunta
If 28% of a segment of DNA is composed of guanine, how much of the segment is adenine?
Respuesta
-
7%
-
22%
-
28%
-
There is no way to determine this.
Pregunta 56
Pregunta
How did the work of Franklin and Wilkins contribute to the discovery of the structure of DNA?
Respuesta
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They determined the rule of base pairing
-
They determined that DNA has an X shape
-
They determined the double helix structure
-
They determined that the strands run antiparallel
Pregunta 57
Pregunta
Which of these findings made Watson and Crick confident that their DNA model was correct?
Respuesta
-
Chargaff's base-pairing ratios
-
Pauling's three-strand model
-
Franklin's early disagreement with the double helix theory
-
All of the above
Pregunta 58
Pregunta
What would have been the results of Meselson and Stahl's experiment if DNA had undergone conservative replication?
Respuesta
-
one band containing only 14N
-
one band containing only 15N
-
two bands: one of 15N and 14N
-
three bands: one of 15N, one of 14N, and one of 1:1 14N:15N
Pregunta 59
Pregunta
Which characteristics of the structure of DNA results in a lagging strand and a leading strand during DNA replication?
Respuesta
-
its phosphate backbone
-
its antiparallel strands
-
the ratio of purines to pyrimidines
-
the full twist every ten nucleotides
Pregunta 60
Pregunta
What is the function of DNA ligase in replication?
Respuesta
-
It initiates a replication bubble
-
It prevents DNA strands from tangling
-
It places nucleotides to form a new DNA strand
-
It fills gaps on the lagging strand
Pregunta 61
Pregunta
Which method do prokaryotes use to compact DNA?
Respuesta
-
Spooling around a histone
-
Forming a nucleosome
-
Supercoiling
-
Winding into solenoids
Pregunta 62
Pregunta
Where are telomeres located?
Respuesta
-
At ends of chromosomes
-
On the leading strand
-
At the replication fork
-
On prokaryotic plasmids
Pregunta 63
Pregunta
What is the name of Beadle and Tatum's original hypothesis?
Respuesta
-
One gene-one sequence hypothesis
-
One gene-one enzyme hypothesis
-
One gene-one peptide hypothesis
-
One gene-one polypeptide hypothesis
Pregunta 64
Pregunta
What is the sequence of information transfer, as outlined by the central dogma?
Respuesta
-
DNA -> tRNA -> mRNA --> polypeptide
-
DNA -> mRNA -> tRNA --> polypeptide
-
DNA -> mRNA -> rRNA --> polypeptide
-
DNA -> rRNA -> tRNA --> polypeptide
Pregunta 65
Pregunta
Where is the TATA box found?
Respuesta
-
In the termination sequence that stops DNA polymerase
-
In the termination sequence that stops RNA polymerase
-
In the promoter that enables the binding of DNA polymerase
-
In the promoter that enables the binding of RNA polymerase
Pregunta 66
Pregunta
What happens during capping and tailing?
Respuesta
-
A methyl 5' tail and poly(A) cap are added
-
A methyl 3' tail and poly(A) cap are added
-
A methyl 5' cap and poly(A) tail are added
-
A methyl 3' cap and poly(A) tail are added
Pregunta 67
Pregunta
How is the lac operon inhibited?
Respuesta
-
The lac repressor is not synthesized by the lacl gene
-
RNA polymerase is inhibited by high concentrations of allolactase
-
The lac repressor is inhbited by high concentrations of allolactase
-
Allolactase is not present to bind with the lac repressor
Pregunta 68
Pregunta
Which term refers to a point mutation that results in a different amino acid in a particular position?
Respuesta
-
Missense mutation
-
Silent mutation
-
Nonsense mutation
-
Frameshift mutation
Pregunta 69
Pregunta
What is the molecular tool scientists use to cut a DNA fragment from a larger piece of DNA?
Respuesta
-
Restriction enzymes
-
DNA primase
-
Methylase
-
DNA ligase
Pregunta 70
Pregunta
After excising a DNA fragment that contains a target gene, what should a molecular biologist do?
Respuesta
-
Introduce a vector into a suitable organism
-
Isolate a desired gene or DNA fragment
-
Select the transformed cells
-
Insert the gene into a vector
Pregunta 71
Pregunta
Which chemical compound can be used to stain a completed electrophoresis gel?
Respuesta
-
Ethidium bromide
-
Loading dye
-
Molecular marker
-
DNA polymerase
Pregunta 72
Pregunta
During PCR, double-stranded DNA is separated into two single strands of DNA. What is this step called?
Respuesta
-
Splicing
-
Denaturation
-
Extension
-
Annealing
Pregunta 73
Pregunta
After 8 PCR cycles, how many target sequences have been synthesized?
Respuesta
-
8
-
16
-
240
-
256
Pregunta 74
Pregunta
How does genetic therapy differ from traditional methods of treating a disease?
Respuesta
-
It targets the effects of the disease
-
In some cases, it fixes the genetic code itself
-
It reverses the damage done to the body
-
It replaces the need for organ transplant
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