Genetics Essentials: exam 4 do better Flashcards


Set Details Share
created 6 years ago by roxasiceblue
760 views
book cover
Genetics Essentials
Chapters 12, 13, 16, 18
updated 5 years ago by roxasiceblue
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:
1

Trp operon responding to tryptophan

A) Positive regulation of an inducible system
B) Negative regulation of an inducible system
C) Positive regulation of a repressible system
D) Negative regulation of a repressible system

D

2

Lac operon responding to lactose

A) Positive regulation of an inducible system
B) Negative regulation of an inducible system
C) Positive regulation of a repressible system
D) Negative regulation of a repressible system

B

3

Lac operon responding to glucose

A) Positive regulation of an inducible system
B) Negative regulation of an inducible system
C) Positive regulation of a repressible system
D) Negative regulation of a repressible system

C

4

7) Leu operon responding to leucine

A) Positive regulation of an inducible system
B) Negative regulation of an inducible system
C) Positive regulation of a repressible system
D) Negative regulation of a repressible system

D

5

Yeast genes responding to galactose

A) Positive regulation of an inducible system
B) Negative regulation of an inducible system
C) Positive regulation of a repressible system
D) Negative regulation of a repressible system

A

6

9) Yeast genes responding to tryptophan

A) Positive regulation of an inducible system
B) Negative regulation of an inducible system
C) Positive regulation of a repressible system
D) Negative regulation of a repressible system

C

7

The major cause of allele frequency change in short term population studies

A. Cladogenesis
B. Anagenesis
C. Genetic Drift
D. Allopatric
E. Sympatric

C

8

Involves changes in chromosome number

A. Cladogenesis
B. Anagenesis
C. Genetic Drift
D. Allopatric
E. Sympatric

E

9

Separated populations becoming new species
A. Cladogenesis
B. Anagenesis
C. Genetic Drift
D. Allopatric
E. Sympatric

D

10

Genetic changes accumulating within a species B
A. Cladogenesis
B. Anagenesis
C. Genetic Drift
D. Allopatric
E. Sympatric

B

11

The point of speciation

A. Cladogenesis
B. Anagenesis
C. Genetic Drift
D. Allopatric
E. Sympatric

A

12

20 ) The Ames test includes liver extract because
a) Ames hated liver
b) liver absorbs substances which might be toxic to the bacteria
c) liver metabolizes chemicals to a mutagenic form
d) this allows the testing of the affect of the chemicals on eukaryotic DNA

C

13

Which of the following is true
a) Proto-oncogenes are the gas pedal and tumor suppressor genes are the brakes
b) Proto-oncogenes are the brakes and tumor suppressor genes are the brakes
c) Proto-oncogenes are the gas pedal and tumor suppressor genes are the gas pedal
d) Proto-oncogenes are the brakes and tumor suppressor genes are the gas pedal

A

14

22) Linear relationship of number of mutations to evolutionary distance
A. Horizontal Gene transfer
B. Nonsynonymous substitutions
C. Synonymous substitutions
D. Molecular clock
E. Phylogenetic tree

D

15

23) Does not change amino acid sequence
A. Horizontal Gene transfer
B. Nonsynonymous substitutions
C. Synonymous substitutions
D. Molecular clock
E. Phylogenetic tree

C

16

24) Changes amino acid sequence
A. Horizontal Gene transfer
B. Nonsynonymous substitutions
C. Synonymous substitutions
D. Molecular clock
E. Phylogenetic tree

B

17

25) Large part of a chromosome moving to a different species
A. Horizontal Gene transfer
B. Nonsynonymous substitutions
C. Synonymous substitutions
D. Molecular clock
E. Phylogenetic tree

A

18

26) Representation of evolutionary distance and common ancestry

A. Horizontal Gene transfer
B. Nonsynonymous substitutions
C. Synonymous substitutions
D. Molecular clock
E. Phylogenetic tree

E

19

28) Which of the following statements is true?
a. In the absence of allolactose, the lac operon is constitutively transcribed.
b. In the absence of tryptophan, the genes of the trp operon are not expressed.
c. When a structural gene is under positive inducible control, a mutation that eliminates the activator will cause the structural gene to
be constitutively expressed.
d. When a structural gene is under positive repressible elimination of the repressor will cause the structural gene to not be expressed.
e. An inducible gene is transcribed when a specific substrate is present.

E

20

30) What does an Internal Node represent on a phylogenetic tree?
A.Evolutionary time
B. A common ancestor
C. The point of evolution
D. Level of divergence

B

21

A repressor can only function in a
a) inducible system
b) repressible system
c) negatively regulated system
d) positively regulated system
e) all of these systems

E

22

Which of the following is likely to have the most serious mutational outcome
a) frameshift
b) missense
c) silent
d) transition
e) transversion

A

23

33) Why won’t the number of DNA mutations in a gene always be proportional to evolutionary time of separation?
A.Can’t read mutations from fossils
B.Not all living things use DNA as their genetic material
C.Mutations aren’t related to evolution
D.Some mutations occur less frequently since they change amino acids
E.Mutation rates change in different environments

D

24

Which of the following is not a transversion?
a) A to G
b) G to T
c) A to C
d) G to C
e) T to A

A

25

Operons which regulate the production of amino acids often have an attenuator/leader sequence in addition to the operator because:
a) Amino acids can be toxic and need to be tightly regulated
b) The attenuator actually determines expression level, not the operator
c) The enzymes produced by these operons would waste resources if produced when not needed
d) Attenuators need ribosomes to function

C

26

The main way that a species acquires new genes with novel functions is:
A. Gene duplication followed by divergence
B. Vertical gene transfer
C. Horizontal gene transfer
D. Mutation
E. Natural selection

A

27

What is the major factor defining a species?
A. Similar appearance
B. Reproductive isolation
C. Which genus it is part of
D. Common DNA sequences
E. Survival of the fittest

B

28

41) Uses methylation to determine which strand to change
A mismatch repair
B SOS response
C Tautomerization
D Acridine Dyes
E Direct repair

A

29

42) outcome of multiple UV damage
A mismatch repair
B SOS response
C Tautomerization
D Acridine Dyes
E Direct repair

B

30

43) Causes frameshifts
A mismatch repair
B SOS response
C Tautomerization
D Acridine Dyes
E Direct repair

D

31

44) Removes specific methyl groups

A mismatch repair
B SOS response
C Tautomerization
D Acridine Dyes
E Direct repair

E

32

45) Caused by the many double bonds in the nitrogenous bases

A mismatch repair
B SOS response
C Tautomerization
D Acridine Dyes
E Direct repair

C

33

47) A neural cell cannot give rise to a muscle cell. This is known as
A. totipotent cell
B. differentiation
C. determination
D. methylation
E. brains over brawn

C

34

The signal for high glucose levels in a bacterial cell is
A. high cAMP
B. low cAMP
C. high ATP
D. CAP binds to operator
E. Repressor binding

B

35

A wingless fruit fly is isolated from a population after exposure of the parental generation to EMS. Eventually the mutation is shown to have occurred within the coding sequence of a gene that changes a 5’-GGC-3’ codon (encoding glycine) to a 5’- AGC-3’ codon (encoding serine). Which term would not correctly describe this mutation?
a. Transversion
b. Induced
c. Substitution
d. Missense
e. Loss-of-function

A

36

3. Which of the following statements about an animal bearing a somatic mutation is true?
a. Some but not all of the animal's offspring will also carry the mutation.
b. All of the animal's offspring will carry the mutation.
c. Both the animal and its offspring will show the mutant trait.
d. The animal but not its offspring can be affected by the mutation
e. None of the above

D

37

Which of the following is most likely to cause a frameshift mutation?
a. Base analog
b. Alkylating agent
c. Intercalating agent
d. Ionizing radiation
e. UV light

C

38

9. In the absence of glucose, the CAP protein binds to a DNA sequence adjacent to the promoter of the lac operon. Binding of CAP helps RNA polymerase to bind to the promoter and allows for a high level of transcription of the lac operon. Regulation of the lac operon by the CAP protein is an example of
a. negative regulation.
b. positive regulation.
c. induction.
d. an allosteric effect.
e. constitutive expression.

B

39

11) Photoreactivation repairs DNA using
A. Blue light
B. UV light
C. ATP
D. ligase
E. Elmerʼs glue

A

40

Which of the following kinds of mutations is most likely to be null loss-of-function?
a. Transition
b. Transversion
c. Frameshift
d. Missense

C

41

In Burkitt lymphoma patients, despite translocation, the oncogene c-MYC remains intact in its new location. Yet c-MYC is believed to be responsible for the lymphoma because
a. the c-MYC DNA sequence undergoes hypermethylation.
b. the c-MYC DNA sequence is intact but is inverted in the new position.
c. the c-MYC gene is placed under the control of B-cell-specific gene promoter.
d. the c-MYC gene is placed under the control of B-cell-specific gene regulatory sequences.

D

42

The lac repressor functions as a tetramer and requires binding of all four sites before it releases because:
a) Four is a lucky number for geneticists
b) A tetramer binds the DNA better
c) A tetramer is more accurate in finding DNA sequences
d) This assures that lactose levels are high before the operon turns on

D

43

The open reading frame in the leader region of the trp operon is deleted. The effect will be:
A. Termination of most transcripts
B. No termination of most transcripts
C. Improper translation of the structural genes
D. Normal regulation of transcription
E. Random regulation of transcription

A

44

Which element of the lac operon can act in cis or trans?
a. Operator
b. I gene
c. Structural genes
d. Promoter
e. CAP-binding site

B

45

18. Which statement about the genetic code is not true?
a. Coding sequences are read in groups of three adjacent nucleotides.
b. No codon normally specifies more than one amino acid.
c. Each species of organisms has its own unique genetic code.
d. Some amino acids are specified by more than one codon.
e. Genetic messages are punctuated with start and stop signals.

C

46

In catabolite repression of the lac operon, glucose affects most directly the
a. catabolite-activating protein
b. level of ATP.
c. lac repressor.
d. lac operator.
e. level of cAMP.

E

47

Myoglobin is a protein in muscle cells that consists of a single polypeptide. If you are concerned with interactions between amino acids that stabilize its overall three-dimensional structure in muscle cells, you are concerned with its _____________ structure.
a. quaternary
b. tertiary
c. secondary
d. primary
e. None of the above

B

48

A mutant E. coli strain, grown under conditions that normally induce the lac operon, does not produce ß-galactosidase. What is a possible genotype of the cells?
a. lacI+ lacP+ lacO+ lacZ+ lacY– lacA+
b. lacI+ lacP+ lacOc lacZ+ lacY+ lacA+
c. lacl+ lacP+ lacO+ lacZ+ lacY+ lacA+
d. lacI+ lacP– lacO+ lacZ+ lacY+ lacA+

D

49

Which event is not normally associated with development of cancer?
a. Inactivation of a tumor-suppressor gene in a cell
b. Inactivation of a proto-oncogene in a cell
c. Infection of a cell with a virus that carries an oncogene
d. Chromosome rearrangements including insertions and deletions
e. Activation of genes encoding telomerase in somatic cells
.

B

50

28. Control of the E. coli lac operon by lac I is most accurately described as
a. negative inducible.
b. negative repressible.
c. positive inducible.
d. positive repressible

A

51

An operon is controlled by a repressor. When the repressor binds to a small molecule, it binds to DNA near the operon. The operon is constitutively expressed if a mutation prevents the repressor from binding to the small molecule. Control of this operon is
a. negative inducible.
b. negative repressible.
c. positive inducible.
d. positive repressible

B

52

33. transversion
a. pyrimidine dimers
b. nucleotide-excision repair
c. A•T--> G•C
d. dominant
e. A•T --> C•G

E

53

34. xeroderma pigmentosum
a. pyrimidine dimers
b. nucleotide-excision repair
c. A•T--> G•C
d. dominant
e. A•T --> C•G

B

54

35. gain-of-function mutant
a. pyrimidine dimers
b. nucleotide-excision repair
c. A•T--> G•C
d. dominant
e. A•T --> C•G

D

55

36. ultraviolet light
a. pyrimidine dimers
b. nucleotide-excision repair
c. A•T--> G•C
d. dominant
e. A•T --> C•G

A

56

37. transition a. pyrimidine dimers
b. nucleotide-excision repair
c. A•T--> G•C
d. dominant
e. A•T --> C•G

C

57

2) Which feature of gene regulation is present only in prokaryotic genomes?
A. Gene dosage
B. Activators
C. Enhancers
D. Alternative splicing
E. Attenuators

E

58

8) The corepressor of tryptophan biosynthesis is
A. tRNATrp
B. Tryptophan
C. Tryptophanase
D. Tryptophan attenuator
E. None of the above

B

59

What is a silent mutation?
a) A change that adds or deletes a base from a codon
b) A change causing the protein to start in the wrong place
c) A change from an amino acid codon to a stop codon
d) A change in a degenerate codon position that doesn't change the meaning of the codon
e) A change from a codon for one amino acid to a codon for another amino acid

D

60

Which of the following crosses will result in hybrid dysgenesis?
a) P- male X P- female
b) P+ male X P+ female
c) P+ male X P- female
d) P- male X P+ female

C

61

In the presence of lactose and glucose, which of the following bacteria will not produce high levels of lacZ
A. I+O+Z+
B. I+OCZ+
C. ISO+Z+
D. I-O+Z+
E. None will produce lacZ

E

62

Approximately how big would the average fragment size be following digestion with a restriction enzyme that recognizes a 6 base pair sequence?
a) 500 bp
b) 1000 bp
c) 2500 bp
d) 4000 bp
e) 6000 bp

D

63

Which factor binds to the TATA box in eukaryotic Pol II promoters
A. TFIA
B. TFIID
C. TFIIID
D. TFIB
E. TFIIIB

B

64

ddNTP is missing the hydroxyl at the
a) 5’ and 3’ position
b) 1’ and 2’ position
c) 2’ and 3’ position
d) 2’ and 5’ position
e) 4’ and 5’ position

C

65

40) Insertion sequences (IS) inserted in the genome are flanked by:
a) Inverted genomic repeats and Inverted sequence elements
b) Direct genomic repeats and Direct sequence elements
c) Inverted genomic repeats and Direct sequence elements
d) Direct genomic repeats and inverted sequence elements

D

66

You perform interrupted-mating experiments on three Hfr strains (A, B, and C). Genes are transferred (from last to first) in the following order from each strain: strain A, thi-his-gal-lac-pro; strain B, lac-gal-his-thi-thr; strain C, azi-leu-thr-thi-his. How are the F factors in these strains oriented?
a. A and B are oriented in the same direction.
b. B and C are oriented in the same direction.
c. A and C are oriented in the same direction.
d. All of them are oriented in the same direction.

C

67

A bacterium of genotype a+b+c+d+ is the donor in a cotransformation mapping. The recipient is a–b–c–d–. Data from the transformed cells are shown below. What is the order of the genes?
a+ and d+ 2
d+ and c+ 0
b+ and d+ 5
a+ and c+ 5
b+ and a+ 0
c+ and b+ 0
a. a c b d
b. a d c b
c. c b a d
d. c a d b

D

68

A co-transduction experiment is carried out to map genes A, B and C in E. coli. Out of 10 million phage lambda tested, 250 cotransduced A and C, 25 cotransduced B and C and none cotransduced A and B. This indicates that:
A. All three are on different chromosomes
B. A and B are on different chromosomes
C. B and C are the closest markers
D. A and B are the closest markers
E. C is the middle marker

E

69

The response of the yeast Gal4 (galactose) gene to galactose is an example of
A. an inducible system with negative regulation
B. a repressible sytem with negative regulation
C. an inducible system with positive regulation
D. a repressible sytem with positive regulation

C

70

A wingless fruit fly is isolated from a population after exposure of the parental generation to EMS. Eventually the mutation is shown to have occurred within the coding sequence of a gene that changes a 5’-GGC-3’ codon (encoding glycine) to a 5’-GGG-3’ codon (encoding glycine). Which term would not correctly describe this mutation?
a. Transversion
b. Induced
c. Substitution
d. Missense
e. Loss-of-function

D

71

The signal for high glucose levels in a bacterial cell is
A. high cAMP
B. low cAMP
C. high ATP
D. CAP binds to operator
E. Repressor binding

B

72

The genes which act as the brakes for cell growth are the
A. proto-oncogenes
B. slow-down genes
C. oncogenes
D. growth-halting genes
E. tumor-suppressor genes

E

73

The histone core consists of
A. Four polypeptides
B. Six polypeptides
C. Eight polypeptides
D. Nine polypeptides

C

74

47) ras

A. Gap gene
B. cyclin
C. proto-oncogene
D. tumor suppressor gene
E. Coordinate gene

C

75

49) retinablasoma gene
A. Gap gene
B. cyclin
C. proto-oncogene
D. tumor suppressor gene
E. Coordinate gene

D

76

62) Determines the proper position of neuron outgrowth in mice and humans
A. Antennaepedia
B. Hox
C. Ultrabithorax
D. Homeotic genes

B

77

Operons allow coordinate regulation of genes involved in the same processes

A. Always True
B. Always False
C. Usually True
D. Usually False

C

78

Multigene families
A. Are always involved in immune functions
B. Use the same promoter
C. Have the same sequence
D. Encode protein subunits
E. Probably arose through gene duplication

E

79

The majority of genes identified by genomics:
A. Are involved in translation
B. Are involved in transcription
C. Have no clearly identified function
D. Only make non-coding RNA
E. Are uniformly distributed on the chromosomes

C

80

59) Antibody diversity is increased by
A. Break-chew-add
B. Somatic hypermutation
C. Somatic hypomutation
D. Somatic-Chew-Break
E. Break-chew-hypermutation

B

81

Two-dimension gels separate proteins based on
A. size and size
B. hydrophobicity and size
C. hydrophobicity and charge
D. size and color
E. charge and size

E

82

Relative fitness is:
A. The percentage of a given genotype found in the next generation
B. The percentage of a given phenotype found in the next generation
C. The number of animals that survive in a population
D. The number of offspring an individual with a certain genotype will produce
E. The chances of an individual with a certain phenotype surviving for a year

A

83

23) Needs visible light to work
A mismatch repair
B photoreactivation
C Tautomerization
D Acridine Dyes
E excision repair

B

84

24) Causes frameshifts
A mismatch repair
B photoreactivation
C Tautomerization
D Acridine Dyes
E excision repair

D

85

25) Needs Pol I and ligase to complete the repair
A mismatch repair
B photoreactivation
C Tautomerization
D Acridine Dyes
E excision repair

E

86

26) Caused by the many double bonds in the nitrogenous bases

A mismatch repair
B photoreactivation
C Tautomerization
D Acridine Dyes
E excision repair

C

87

A phage with a genome of 10,000 base pairs has a Cot 1/2 value of 5. What is the expected Cot 1/2 of a phage with a 20,000 base pair genome?
a) 5
b) 10
c) 2.5
d) 20
e) cannot be determined with the information provided

B

88

2) Used to add restriction site to the ends of cDNAs
a) Steroid hormone
b) linker
c) Short tandem repeats
d) Haematopoesis
e) DAM methylase

B

89

3) Different numbers of these are detected in DNA fingerprinting
a) Steroid hormone
b) linker
c) Short tandem repeats
d) Haematopoesis
e) DAM methylase

C

90

4) Derived from cholesterol
a) Steroid hormone
b) linker
c) Short tandem repeats
d) Haematopoesis
e) DAM methylase

A

91

5) Study of the formation of blood vessels
a) Steroid hormone
b) linker
c) Short tandem repeats
d) Haematopoesis
e) DAM methylase

D

92

6) Helps mark the old strand during DNA replication

a) Steroid hormone
b) linker
c) Short tandem repeats
d) Haematopoesis
e) DAM methylase

E

93

A bacteria mutant for lacY (galactoside permease) will be:
A. always repressed for lac operon transcription
B. constitutively on for lac operon transcription
C. normally inducible for lac operon transcription
D. have a lower induced response for lac operon transcription

A

94

Which of the Following is true?
A. Inversions and reciprocal translocations both interfere with recombination
B. Inversions and reciprocal translocations both interfere with forming gametes with the correct chromosome balance
C. Inversions interfere with forming gametes with the correct chromosome balance, reciprocal translocations with recombination
D. Inversions interfere with recombination, reciprocal translocations with forming gametes with the correct chromosome balance

D

95

The response of the lac operon to glucose is an example of
A. an inducible system with negative regulation
B. a repressible sytem with negative regulation
C. an inducible system with positive regulation
D. a repressible sytem with positive regulation

D

96

26) adds a side group onto the rings of DNA bases
A xeroderma pigmentosa
B photoreactivation
C alkylating agents
D Acridine Dyes
E excision repair

C

97

27) cuts out a set number of bases of single stranded DNA
A xeroderma pigmentosa
B photoreactivation
C alkylating agents
D Acridine Dyes
E excision repair

E

98

28) increased sensitivity to UV light
A xeroderma pigmentosa
B photoreactivation
C alkylating agents
D Acridine Dyes
E excision repair

A

99

29) repairs DNA in bacteria, but not people
A xeroderma pigmentosa
B photoreactivation
C alkylating agents
D Acridine Dyes
E excision repair

B

100

30) intercalates into DNA A xeroderma pigmentosa
B photoreactivation
C alkylating agents
D Acridine Dyes
E excision repair

D

101

Which nucleotide is methylated in eukaryotic DNA to indicate a region which should be inactivated through compression?
a) ATP
b) CTP
c) GTP
d) TTP

B

102

What is a missense mutation?
a) A change that adds or deletes a base from a codon
b) A change causing the protein to start in the wrong place
c) A change from an amino acid codon to a stop codon
d) A change in a degenerate codon position that doesn't change the meaning of the codon
e) A change from a codon for one amino acid to a codon for another amino acid

E

103

Pick from the following:
a. Pericentric inversions cause dicentric and acentric chromosomes, paracentric does not
b. Paracentric inversions cause dicentric and acentric chromosomes, pericentric does not
c. Both Pericentric and paracentric inversions cause dicentric and acentric chromosomes
d. Neither Pericentric nor paracentric inversions cause dicentric and acentric chromosomes

B

104

Phage lambda’s decision to go lytic or lysogenic is a model for
A. A binary developmental decision
B. Randomness of protein binding to DNA
C. Multiple choice selection
D. Enhancer activation of developmental pathways
E. Repressors binding to operator sites

A

105

The response of the trp operon to tryptophan is an example of
a) an inducible system with negative regulation
b) a repressible sytem with negative regulation
c) an inducible system with positive regulation
d) a repressible sytem with positive regulation

B

106

A bacterium of genotype a+b+c+d+ is the donor in a cotransformation mapping. The recipient is a–b–c–d–. Data from the transformed cells are shown below. What is the order of the genes?
a+ and b+ 2
a+ and c+ 0
a+ and d+ 5
b+ and c+ 5
b+ and d+ 0
c+ and d+ 0
a. a c b d
b. a d c b
c. c b a d
d. c a d b

C

107

By measuring the UV-melting curves for the DNA of two different organisms (A and B) in the same solution and concentration, we have found the following melting temperatures (Tm): Tm(A)= 70.2 C and Tm(B)=75.6 C. Which of the following is correct?
a. Both DNA molecules are equally thermally stable.
b. Both DNA molecules have equimolar A,C,G,T
c. A has more guanine than B
d. B has more guanine than A

D

108

An immunization confers future resistance because of
A. Immunogens
B.antigens
C. junctional diversity
D. memory cells
E. somatic hypermutation

D

109

B Cells get their name from
A.Bone Marrow
B. Bursa
C. They are the second cells in the order A, B, C, etc.
D. Best
E. Botulin

B

110

What is the difference between a structural gene and a regulator gene?

a. Structural genes are transcribed into mrNa, but regulator genes are not. b. Structural genes have complex structures; regulator genes have simple structures. c. Structural genes encode proteins that function in the structure of the cell; regulator genes carry out metabolic reactions. d. Structural genes encode proteins; regulator genes control the transcription of structural genes.

D

111

In a negative repressible operon, the regulator protein is synthesized as

a. an active activator. b. an inactive activator. c. an active repressor. d. an inactive repressor.

D

112

In the presence of allolactose, the lac operon repressor

a. binds to the operator. b. binds to the promoter. c. cannot bind to the operator. d. binds to the regulator gene.

C

113

In the trp operon, what happens to the trp repressor in the absence of tryptophan?

a. It binds to the operator and represses transcription. b. It cannot bind to the operator and transcription takes place. c. It binds to the regulator gene and represses transcription. d. It cannot bind to the regulator gene and transcription takes place.

B

114

Most transcriptional activator proteins affect transcription by interacting with

a. introns. b. the basal transcription apparatus. c. DNa polymerase. d. nucleosomes.

B

115

In rNa silencing, sirNas and mirNas usually bind to which part of the mrNa molecules that they control?

a. 5' Utr b. 5'cap c. 3' poly(a) tail d. 3'Utr

D

116

Which of the following changes is a transition base substitution?

A.Adenine is replaced by thymine. B.Cytosine is replaced by adenine. C.Guanine is replaced by adenine. D.three nucleotide pairs are inserted into DNA.

C

117

Base analogs are mutagenic because of which characteristic?

a. They produce changes in DNA polymerase that cause it to malfunction. b. They distort the structure of DNA. c. They are similar in structure to the normal bases. d. They chemically modify the normal bases.

C

118

Which type of mutation in telomerase can be associated with cancer cells?

A. Mutations that produce an inactive form of telomerase B.Mutations that decrease the expression of telomerase. C.Mutations that increase the expression of telomerase D. All of the above

C

119

Chronic myelogenous leukemia is usually associated with which type of chromosome rearrangement?

a. Duplication b. Deletion c. Inversion d. Translocation

D

120

Which of the following is an example of postzygotic reproductive isolation? a. Sperm of species a dies in the oviduct of species B before fertilization can take place. b. Zygotes that are hybrids between species a and B are spontaneously aborted early in development. c. the mating seasons of species a and B do not overlap. d. Males of species a are not attracted to the pheromones produced by the females of species B.

B

121

In general, changes in which types of sequences are expected to exhibit the slowest rates?

a. Synonymous changes in amino acid–coding regions of exons b. Nonsynonymous changes in amino acid–coding regions of
exons c. Changes in introns d. Changes in pseudogen

B

122

A gene contains a frameshift mutations. Which kind of mutagen would be capable of reversing this mutation ?

A. alkylating agent

B. base analog

C. intercalating agent

D. deaminating chemical

C

123

Which is NOT true of transposable elements ?

A.Many will possess short terminal inverted repeats

B.They often generate short flanking direct repeats

C.They are mobile DNA

D.Their movement will not cause mutations

D

124

What kind of transposition causes an increase in the copy number of transposable elements ?

A.mutagenic transposition

B.All transpositions increase copy number

C.nonreplicative transposition

D.replicative transposition

D

125

What kind of mutation repair does NOT involve the removing and repairing of nucleotides ?

A.nucleotide-excision repair

B.mismatch repair

C. direct repair

D.base-excision repair

C

126

How can spontaneous mutations arise?

A.They can occur during DNA tautomeric shifts

B. They can arise during DNA replication

C.They can arise from depurination and deamination

D.All of these can cause spontaneous mutations

D

127

The class of proteins known as cyclins

A.phosphorylate other cellular proteins

B.act as inhibitors of kinases

C.oscillate in concentration during the cell cycle

D.Express at a steady level throughout the cell cycle

C

128

In normal somatic cells, chromosomes shorten each generation. In cancer cells you notice that the chromosomes are not shortening, even after many cell divisions. A mutation in the expression of which gene might lead to this observation ?

A.DNA polymerase

B.telomerase

C. DNA-repair genes

D.retinoblastoma

B

129

What is the unique property of metastatic cancers?

A.They lose contact inhibition

B.They spread to other tissues

C.They usually arise from mutations

D.They grow out of control

B

130

Helix-turn-helix and zinc finger are structural motifs of
A. Enhancer/promoter interaction
B. DNA binding proteins
C. Methylation enzymes
D. Catabolic enzyme complexes
E. Spliceosomes for primary and alternative splice sites

B

131

27) Which feature of gene regulation is present only in eukaryotes?
A. Alternative splicing
B. mRNA half-life
C. Operons
D. DNA methylation
E. Helix-turn-helix transcriptional activators

A

132

15) Most tumor suppressor genes are
A. mutant
B. DNA binding proteins
C. recessive
D. neutral in effect
E. dominant

C