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Flashcards in exam 2 Deck (102):
1

Which scientist below are principal contributors to regulation of the trp operon?

charles yanofsky

2

Which scientist(s) below is/are principal contributor(s) to regulation of the Trp Operon? YES… respond to the same item again.

A. Charles Yanofsky

3

Which microorganism is touted as the fastest growing bacterium?

A. Vibrio natriegens

4

Which microorganism is touted as the fastest growing bacterium? YES… respond to the same item again.

A. Vibrio natriegens

5

Which is true about biological reduction of nitrogen gas to ammonia?

A. Can be accomplished by free-living organisms in Domains Archaea and Bacteria.
B. Can be accomplished by a variety of symbioses between prokaryotes and eukaryotic macro organisms.
C. Is thermodynamically exergonic but requires high input of cellular energy (ATP).
D. Is catalyzed by an enzyme that typically contains iron and molybdenum co-factors.
E. All of the above are true.

6

Which of the below principles(s) apply to the tendency of systems to go from a lower state of order to a more organized system?

A. entropy
B. First Law of Thermodynamics
C. Second Law of Thermodynamics
D. Chemiosomotic Theory
E. None of the above

7

Enzyme(s) by which bacteria assimilate gaseous molecular nitrogen is/are

A. nitrogenase

8

The Ames test…

A. assesses chemical mutagenicity

9

A bacterium experiencing a severe amino acid shortage

A. may exhibit Stringent Response.
B. will contain elevated levels of ppGpp.
C. will continue biosynthesis of amino acids.
D. will have a high level of uncharged tRNA.
E. will have all of the above properties.

10

Bacterial cells cannot be diploid because…

A. they do not reproduce sexually.

11

Which of the below contributed most to our understanding of sex in bacteria?

A. Joshua Lederberg and Edward Tatum

12

The microorganism that has been exploited to introduce genes from bacteria into plants

A. is Agrobacterium tumefaciens.
B. .
C. is a bacterium.
D. has a tumor-inducing plasmid.

13

Strains of Escherichia coli with F-factor that has integrated into the chromosome are known as

hfr strains

14

Which mechanism(s) do NOT protect nitrogenase from denaturation by molecular oxygen?

A. fixation of nitrogen under aerobic conditions

15

Plasmid copy number is which of the below

A. The ratio between the numbers of a specific plasmid inside a bacterial cell and the number of chromosomes.

16

Nonsense mutations

A. occur when translation “stop codons” are prematurely inserted into mRNA.
B. stop translation of the mRNA into a functional protein.
C. have been given trivial names of “Amber,” Opal,” and “Ochre.”
D. often result in a defective gene product.
E. All of the above

17

Nonsense-suppressor mutations

A. allow a translation stop codon to be ignored.
B. require a change in tRNA specificity.
C. restore in the original, wild phenotype.
D. result in substitution of an amino acid into the position specified by the stop codon in the mRNA.
E. All of the above.

18

Which of the below discovered that a non-living “transforming” material could change an avirulent strain of a bacterium into a virulent, pathogenic microorganism?

. Fred Griffith

19

What was the microorganism used in the above discovery?

A. Streptococcus pneumoniae

20

Who discovered that bacterial conjugation was polar (one way, from donor to recipient)?

A. William Hayes

21

Housekeeping genes are

A. constitutively expressed.
B. essential to growth and life of the cell.
C. useful to determine whether a cell is active even without culturing it.
D. all of the above.
E. none of the above

22

This computer scientist at University of Indiana writes for Scientific American. He/she wrote about Central Dogma in a treatise entitled “Gödel, Escher, Bach: An Eternal Golden Braid.”

A. Douglas Hofstadter

23

Early, seminal experiments that distinguished between genetic exchange mechanisms of bacteria that require physical contact and those that do not employed which of the below?

A. auxotrophic mutants.
B. Escherichia coli
C. U-tube with sintered glass
D. strains of bacteria with multiple biosynthetic deficiencies
E. all of the above.

24

Which pathway produces the most ATP by substrate-level phosphorylation?

A. Embden-Meyerhof-Parnas

25

Which pathway produces the most ATP

A. Electron transport chains coupled to chemiosmosis

26

Who was curator for the genetic map of Escherichia coli for many years?

A. Barbara Bachman

27

The most frequently used eukaryotic microorganism for genetic engineering and recombinant DNA research is which of the below?

A. Saccharomyces cerevisiae

28

Who discovered that a non-living “transforming” material could change a “rough” strain of a bacterium into a “smooth” slimy culture?

A. Fred Griffith

29

Who subsequently demonstrated that the “transforming principle” was DNA?

A. Avery, MacLeod, and McCarty

30

Which microorganism was used in the above studies?

A. Streptococcus pneumoniae

31

Under optimal conditions, the complete transfer of the entire chromosome during an Hfr × F- mating between two strains of Escherichia coli takes approximately __________ minutes.

100

32

Transfer of genetic information between prokaryotes that does NOT require direct physical contact between the donor and recipient cells and does NOT require a bacterial virus is called

A. transformation.

33

Lectins

A. are proteins with an affinity for monosaccharide residues.
B. may be used for ABO-typing of blood.
C. are involved in host-plant selection for nitrogen-fixing symbioses between bacteria and legumes.
D. are produced by legumes (e.g., bean, pea, clover).
E. are all of the above.

34

Cells from which plasmids have been removed by treatment with acridine orange or similar agents are typically termed as being

cured

35

Okasaki fragments

A. accommodate the fact that DNA polymerase must synthesize the new strand from 5’ to 3’

36

The capability of a bacterial strain or species to take up naked DNA is called

competence

37

What principal metabolic advantage does fermentation confer to the cell?

A. Oxidizes reduced electron carriers such as NADH

38

The rolling circle mechanism of DNA replication is utilized

A. by Eukarya.
B. during conjugative transfer of DNA into an F- recipient.
C. Both A and B

39

The most abundant single protein in the biosphere is

A. a key enzyme of the Calvin-Benson-Bassham cycle.
B. RuBisCO.
C. A and B.

40

Which of the below mapping methods yields information on the polar relationship of two genes, e.g., whether gene B is between A and C?

A. interrupted conjugation of Hfr strains

41

For this course, we have adopted which terminology as our definition of a “gene?”

A. DNA polynucleotide sequence that codes for a gene product, e.g., protein, tRNA, rRNA.
B. cistron
C. A and B

42

Auxotrophic mutant bacteria

B. may undergo reversion to their prototrophic forms.

43

Small Interfering, siRNA, or “Silencer RNA” is used to

B. suppress expression of specific genes

44

Who of the below developed a “chemiosmotic” theory that provided a unified mechanism for how ATP was made during respiration and in the light reactions of photosynthesis?

A. Peter Mitchell

45

Nitrogenase

A. is an enzyme.
B. may catalyze reduction of substrates other than nitrogen gas.
C. is highly conserved in Domains Bacteria and Archaea.

46

The use of terminal electron acceptors other than molecular oxygen at the end of an electron transport chain is

A. anaerobic respiration

47

The principle that spontaneous mutations in bacteria are rare and random

A. was supported by a fluctuation analysis experiment.
B. was demonstrated by Max Delbrück and Salvador Luria.
C. was demonstrated using Poisson Distribution.
D. was supported by following acquisition of mutant characteristics during the growth of Escherichia coli in the absence of selection pressures.
E. All of the above

48

The key enzyme(s) by which bacteria assimilate relatively-HIGH concentrations of ammonia is / are

glutamate dehydrogenase or other amino acid dehydrogenases

49

Which bacteriophages tend to be specialized transducing phage?

A. temperate phages
B. phage that integrate their genomes into the host bacterial chromosome.
C. A and B

50

What is the standard unit for mapping the genes on the E. coli chromosome?

minuite

51

What is a “bacteroid? How does it differ from the bacterium form?

Symbiotic form of members of genera Rhizobium or Bradyrhizobium with leguminous plants.

52

Provide correct scientific names for the most common Eukaryotic and Prokaryotic microorganism used for elucidation of gene transcription regulation, in genetic engineering and recombinant DNA research. Designate to which Domain they belong.

Escherichia coli = Bacteria
Saccharomyces cerevisiae = Eukarya

53

Why did Lederberg and Tatum use multiple auxotrophic mutants, i.e., strains with deficiencies in biosynthetic capabilities in several places, in their experiment that demonstrated conjugation in bacteria? Why did others follow up on this same strategy? In a few concise sentences, explain how these strategies might be relevant to spontaneous mutation.

Each mutation has reversion rate of 10*-8 per cell per generation. Thus, 10 in a billion cells will revert to wild type. By using 3 mutants, the likelihood of all three reverting to wild type is infinitesimally small.

54

Discuss Operon Theory

• What is the principal Domain of biological organisms within which Operon Theory was developed? And does it have theoretical meaning outside of that Domain?
• What is an operon? Define it. What are defining components of an operon (sites, genes)?
• What does it do? I.e., what enzymes or other gene products does it control and what do they do for the cell?
• Why are operons important, and what do they explain in biology?
• Who won the Nobel for articulating operon theory; which operon did they use as their model?

55

Uncoupled transport of electrons via an electron transport system to a terminal electron acceptor tends to generate

heat

56

Which of the below developed a “chemiosmotic” theory that provided a unified mechanism for how ATP was made during respiration AND in the light reactions of photosynthesis?

petere mitchell

57

Enzyme(s) by which bacteria assimilate ammonia is/are

nitrogenase

58

The most common organism used in genetic engineering and recombinant DNA research is which of the below?

A. The common gut bacterium, Escherichia coli

59

Hfr strains of Escherichia coli

A. are characterized by an F-factor that has integrated into the chromosome.
B. may form an F’ plasmid that contains chromosomal genetic material.
C. are “male” or donor cells.
D. have sex pili.
E. are characterized by all of the above

60

What principal metabolic advantage does fermentation confer to the cell?

A. Oxidizes reduced electron carriers such as NADH

61

This Harvard M.D. wrote several novels about genetic engineering, most recently the novel NEXT; some of his novels were made into movies, e.g., JURASSIC PARK, THE ANDROMEDA STRAIN

michael crichton

62

Auxotrophic mutants

A. have biosynthetic deficiencies relative to the prototroph.
B. only express their mutant phenotype under certain defined conditions (e.g., high temperature).
D. are useful in determining potential carcinogenicity of chemicals.

63

The enzyme nitrogenase

A. consists of two kinds of subunits.
B. may catalyze reduction of substrates other than nitrogen gas.
C. is highly conserved in Domains Bacteria and Archaea.

64

“ABLE WAS I ERE I SAW ELBA,” “WAS IT A BAR OR A BAT I SAW” and “HE GODDAM MAD DOG EH” are

B. palindromes of alphabetic letters.
C. analogous to insertion sequence sites.
D. analogous to recognition sites for restriction endonucleases.

65

This computer scientist at University of Indiana writes for Scientific American. He/she wrote about Central Dogma in a treatise covering “Gödel, Escher, Bach: An Eternal Golden Braid.”

A. Douglas Hofstadter

66

The most abundant single protein on Planet Earth

B. RuBisCO.

67

The key enzyme(s) by which bacteria assimilate relatively-HIGH concentrations of ammonia is

A. glutamine synthetase.
B. glutamate synthase (GOGAT

68

Nonsense mutations

A. occur when translation “stop codons” are prematurely inserted into mRNA.
B. stop translation of the mRNA into a functional protein.
C. have been given trivial names of “Amber,” Opal,” and “Ochre.”
D. often result in a defective gene product.
E. All of the above.

69

Nonsense-suppressor mutations

A. allow a translation stop codon to be ignored.
B. require a change in tRNA specificity.
C. restore in the original, wild phenotype.
D. result in substitution of an amino acid into the position specified by the stop codon in the mRNA.
E. All of the above.

70

The binding site for the DNA-dependent messenger-RNA polymerase is which of the below?

promoter

71

Which is true about biological reduction of nitrogen gas to ammonia?

A. Can be accomplished by free-living organisms in Domains Archaea and Bacteria.
B. Can be accomplished by a variety of symbioses between prokaryotes and eukaryotic macro organisms.
C. Is thermodynamically exergonic but requires high input of cellular energy (ATP).
D. Is catalyzed by an enzyme that typically contains iron and molybdenum co-factors.
E. All of the above are true

72

Which of the below is NOT a pathway of CO2 fixation that supports autotrophic growth (either chemolithotrophic or photolithotrophic)?

B. Anapleurotic CO2 fixation pathways

73

The DNA site on operons to which the regulator (repressor) protein may bind is known as which of the below?

operator

74

Lectins

A. are proteins with an affinity for monosaccharide residues.
B. may be used for ABO-typing of blood.
C. are involved in host-plant selection for nitrogen-fixing symbioses between bacteria and legumes.
D. are produced by legumes (e.g., bean, pea, clover).
E. are all of the above.

75

Which of the below mapping methods will give information on the polar relationship of two genes, e.g., whether gene B is between A and C?

C. interrupted conjugation

76

Who was curator for the genetic map of Escherichia coli for many years?

D. Barbara Bachman

77

For this course, we have adopted which of the following term(s) as our definition of a “gene

A. Polynucleotide sequence that codes for a gene product, e.g., protein, tRNA, rRNA.
B. cistron

78

Which of the below used radioisotopes to demonstrate that the DNA and not the protein components of bacteriophages directed infection of the host cell?

A. Hershey and Chase

79

Which pathway produces the least ATP by substrate-level phosphorylation?

D. Oxidative Pentose Phosphate Pathway

80

Which of the below showed that mutations in bacteria are rare and spontaneous?

A. Max Delbrück and Salvador Luria

81

Which of the below won a Nobel Prize for what we now call “operon theory?”

A. Francois Jacob and Jacques Monod

82

Who won the Nobel for discovering transposons?

A. Barbara McClintock

83

Which group below has a specialized cell that compartmentalizes nitrogen fixation and sequesters it from oxygenic photosynthesis?

A. filamentous cyanobacteria

84

The principle that bacteria do NOT develop mutants in response to environmental pressures

A. was supported by a fluctuation analysis experiment.
B. was demonstrated by Max Delbrück and Salvador Luria.
C. was demonstrated using Poisson Distribution.
D. was supported by following acquisition of mutant characteristics during the growth of Escherichia coli in the absence of selection pressures.
E. All of the above

85

Under optimal conditions, the complete transfer of the entire chromosome during an Hfr × F- mating between two strains of Escherichia coli takes approximately __________ minutes.

100

86

The transfer of genetic information between prokaryotes that requires direct physical contact between the donor and recipient cells and requires a bacterial virus is called

A. transformation.
B. transduction.
C. Transcendental Meditation.
D. conjugation.
E. none of the above

87

PCR

B. is an in vitro technology.
C. is a method that exponentially amplifies specific segments of template DNA.
D. requires a thermo-stable DNA polymerase

88

Which of the below discovered that a non-living “transforming” material could change an avirulent strain of a bacterium into a virulent, pathogenic microorganism?

A. Fred Griffith

89

What was the microorganism used in the above discovery?

B. Saccharomyces cerevisiae

90

Who discovered that bacterial conjugation was polar (one way, from donor to recipient

A. William Hayes

91

Which mechanism(s) may protect nitrogenase from denaturation by molecular oxygen?

A. Fixation of nitrogen only under anaerobic conditions
B. Compartmentalization of the nitrogen fixation process
C. Partial uncoupling of the respiratory chain (electron transport system) to effect rapid reduction of oxygen
D. oxygen transport proteins such as hemoglobins to sequester oxygen from nitrogenase
E. All of the above

92

The total metabolic capability of an organism is known as its

A. metabalome.

93

Early, seminal experiments that distinguished between genetic exchange mechanisms of bacteria that require physical contact and those that do not employed which of the below?

A. auxotrophic mutants.
B. Escherichia coli
C. U-tube with sintered glass
D. strains of bacteria with multiple biosynthetic deficiencies
E. all of the above.

94

Why did Lederberg and Tatum use multiple auxotrophic mutants in their experiment that demonstrated conjugation in bacteria?

A. They wished to avoid the possibility that spontaneous mutations might result in restoration of the wild-type phenotype

95

Which mechanism of horizontal gene transfer in prokaryotes involves direct physical contact between the donor and recipient cells?

conjugation

96

Which of the below were Nobel Laureates in recognition of their development of DNA sequencing technology?

A. Walter Gilbert and Frederick Sanger

97

RuBisCO” is an enzyme.

TRUE

98

The F- (female) recipient of a successful transfer of the F plasmid becomes a male or F+ cell.

TRUE

99

Which substrate(s) is/are used in a facile assay of nitrogenase activity?

acetylene

100

Nigericin, 2,4-dinitrophenol and valinomycin are

A. respiratory uncoupling agents.
B. ionophores

101

Mutants of bacteria that are defective in biosynthetic capability relative to the wild type can be selected using which of the below?

A. Use of penicillin counter-selection against prototrophs

102

Small Interfering, siRNA, or “Silencer RNA” is used

A. suppress transcription of specific genes.