Chapter 12 Microbiology

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9. Bacterial chromosomes, unlike eukaryotic chromosomes, often consist of a single replicon.

True

False

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13. DNA functions as a storage molecule, holding genetic information for the lifetime of a cellular organism and allowing that information to be duplicated and passed on to its progeny.

True

False

14. Initiation of translation in eukaryotes is similar to that in prokaryotes except that more initiation factors are required in eukaryotes.

True

False

15. The basic differences between RNA and DNA reside in their sugar and pyrimidine bases; RNA has ribose and uracil whereas DNA has deoxyribose and thymine.

True

False

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18. Eukaryotic mRNAs are modified by addition of a poly(A) sequences at the 3' end and 7-methyl guanosine at the 5' end.

True

False

19. The noncoding sequences located between the start codon and the stop codon in interrupted genes are called introns.

True

False

20. The B form of the DNA double helix contains a wider major groove and a narrower minor groove because the two polynucleotide strands are not positioned directly opposite one another in the helical cylinder.

True

False

21. The coding sequence in the DNA of __________ is normally continuous; that is, it is not interrupted by noncoding sequences.

Prokaryotes

Plants

Mammals

Most insects

22. The Y-shaped part of the DNA molecule where the actual replication process occurs is called the replication __________.

Tongue

Fork

Junction

Splice

23. Which of the following nitrogenous bases is usually found in RNA but not in DNA?

Adenine

Thymine

Uracil

Guanine

24. The protein coding sequences in interrupted genes are called exons.

True

False

25. The portion of the tRNA molecule that binds to the codon on the mRNA is called the

C-codon

Anticodon

Complimentary codon

Paracodon

26. The genetic information in DNA is divided into units called

Proteins

Genes

Genotype

Phenotype

27. When a DNA molecule is replicated, the daughter molecules contain one strand of parental DNA and one strand of newly synthesized DNA; this is called __________ replication.

Hemiconservative

Conservative

Semiconservative

Dispersive

28. The transcribed and translated region of a gene is the __________ region.

Leader

Promoter

Coding

Trailer

29. Some microbial proteins are spliced after translation in a reaction that results in removal of one or more internal intervening sequences called inteins.

True

False

30. The genetic code is usually translated in a nonoverlapping fashion.

True

False

31. Which of the following is not a termination codon?

AUG

UAA

UAG

UGA

32. Which of the following is not a complementary base pair usually found in DNA molecules?

Adenine-thymine

Guanine-cytosine

Adenine-uracil

All of the choices

33. The region at which the RNA polymerase binds is the __________ region.

Leader

Promoter

Coding

Trailer

34. In __________ ribosomes can attach to the mRNA and begin translation even though transcription has not been completed.

Prokaryotes

Eukaryotes

Fungi

Protozoa and some plants

35. The chromosomes of most bacteria are comprised of

Double-stranded circular molecules

Double-stranded linear molecules

Single-stranded circular molecules

Single-stranded linear molecules

36. Posttranscriptional modifications that yield eukaryotic mRNAs include which of the following?

Splicing to remove introns

5' poly (A) tracts  

3' caps

All of the choices

37. Which of the following is the initiator codon?

AUG

UAA

UAG

UGA

38. RNA polymerase II of eukaryotes is responsible for transcribing

RRNA

MRNA

TRNA

All of the above

39. During replication the 2 strands of the DNA molecule are unwound from one another by enzymes called

Ligases

Unwindases

Helicases

Primases

40. The expressed regions of split genes are called

Exons

Endons

Introns

Codons

41. The genetic code is translated in groups of __________ bases

Two

Three

Four

Five

42. ________ molecules deliver amino acids to ribosomes during translation.

Messenger RNA (mRNA)

Transfer RNA (tRNA)

Ribosomal (rRNA)

Heterogeneous nuclear RNA (hnRNA)

43. Prokaryotic DNA replication occurs at a rate of

750–1,000 base pairs per second

750–1,000 base pairs per minute

50–100 base pairs per second.

50–100 base pairs per minute.

44. Split or interrupted genes have been found in eukaryotes but not in prokaryotes.

True

False

45. A complex consisting of a single mRNA molecule with several ribosomes is called a

Polysome

Multisome

Maxisome

None of the choices

46. The principle of transformation was first demonstrated by which of the following individuals or groups of individuals?

Avery, MacLeod, and McCarty

Griffith

Hershey and Chase

Watson and Crick

47. Which of the following is not a pyrimidine?

Adenine

Cytosine

Thymine

Uracil

48. The strand of DNA for a particular gene that is copied by the RNA polymerase to form mRNA is called the __________ strand.

Leading

Template

Transcription

Copy

49. The genetic code is said to be __________ because more than one codon will specify a particular amino acid.

Ambiguous

Degenerate

Multiplicative

Repetitious

50. How many different termination codons are used in translation?

One

Two

Three

Four

51. Ribosomes consist of __________ separate subunits that come together as part of the initiation process and dissociate immediately after termination.

Two

Three

Four

Five

52. Which of the following individuals or groups of individuals demonstrated that the transforming principle was DNA?

Avery, MacLeod, and McCarty

Griffith

Hershey and Chase

Watson and Crick

53. Over twisting or under twisting of helical DNA generates

Hypertwists

Hypotwists

Hypercoils

Supercoils

54. Which of the following is true about the structure of DNA?

Purine and pyrimidine bases are attached to the 1'-carbon of the deoxyribose sugars.

Purine and pyrimidine bases are joined by phosphodiester bonds.

Adjacent bases are stacked on top of each other, one base pair every 0.34 nm.  

All of the choices

55. Which of the following is not considered the final product of the expression of a gene?

A polypeptide chain

An mRNA molecule

A tRNA molecule

An rRNA molecule

56. In eukaryotes a series of __________ residues are added to the 3' end of an RNA molecule as part of the posttranscriptional processing used to produce functional mRNA.

Adenine

Guanine

Cytosine

Uracil

57. Key sequences exist within promoters, which vary somewhat among various promoters but are sufficiently constant that they can be represented by a sequence of bases most often found at each position. These representations are called __________ sequences.

Convergence

Idealized

Consensus

Common

58. The __________ reaction sequentially links adjacent amino acids into the growing polypeptide chain.

Dipeptidation

Transpeptidation

Peptidation

Propeptidation

59. When RNA polymerase catalyzes the addition of a nucleotide to a growing mRNA chain, a byproduct of this reaction is

Phosphate

Pyrophosphate

Orthophosphate

Water

60. The energy needed for protein synthesis is provided by the hydrolysis of

ATP

GTP

UTP

ATP and GTP

ATP and UTP

61. The process by which the base sequence of all or a portion of a DNA molecule is used to direct the synthesis of an RNA molecule is called

Replication

Transcription

Reverse transcription

Translation

62. What is the minimum number of aminoacyl-tRNA synthetase enzymes needed to attach amino acids to all the various tRNA molecules?

20

61

64

As many as there are different tRNAs

63. DNA replication is a complex process, and as a result the frequency of error is quite high.

True

False

64. The unexpressed regions of split genes are called

Exons

Endons

Introns

Codons

65. Because of its larger size, the replication rate of eukaryotic genomes is significantly faster than the replication rate of prokaryotic genomes.

True

False

66. In order to add a single amino acid to a growing polypeptide chain, a grand total of __________ molecules or ATP or GTP are utilized.

Two

Three

Four

Six

67. Each chromosome has one or more __________ site(s) where replication begins.

Promoter

Replicon

Origin

Bifurcate

68. Which of the following is in the coding region of a gene?

Promoter

Leader

Trailer

None of the choices

69. A section of DNA that codes for a protein or other functional product is called a(n)

Codon

Gene

Replicon

Anticodon

70. The Pribnow box of E. coli

Is centered approximately 35 bp upstream of the start site of transcription

Is centered between 7 and 13 bp upstream of the start codon

Is centered approximately 10 bp upstream of the start site of transcription

Is located at the site of addition of poly (A) in eukaryotic mRNAs

71. The transcribed, but not translated, sequence that is immediately upstream of the region and encodes the functional product is called the __________ region.

Leader

Promoter

Coding

Trailer

72. The process by which the base sequence of an RNA molecule is used to direct the synthesis of a protein is called

Replication

Transcription

Reverse transcription

Translation

73. RNA polymerase III of eukaryotes is responsible for transcribing

RRNA

MRNA

TRNA

All of the above

74. A bacterial __________ is the nontranscribed region of the DNA to which RNA polymerase binds in order to initiate transcription.

Operon

Operator

Promoter

Initiatior

75. All prokaryotes initiate the synthesis of proteins with formylmethionine.

True

False

76. The stop codons are translated codons; that is, they specify amino acids to be inserted into the last position of a growing polypeptide chain.

True

False

Chapter 12 Microbiology

1. The __________ is the collection of characteristics of an organism that an investigator observes.

2.

What first name or nickname would you like us to use?

2. The __________ describes the specific set of genes an organism possesses.

3. As prokaryotes normally only have one set of genes, they are called __________.

4. The two strands of a DNA molecule are __________; that is, they are oriented in opposite directions.

5. Aminoacyl-tRNA synthetases catalyze covalent addition of __________ __________ to tRNAs. (2 words)

6. On mRNA molecules, a nontranslated sequence called the ___________ usually precedes the initiation codon.

7. Messenger RNA molecules that direct the synthesis of more than one polypeptide are said to be __________.

8. A consensus sequence in the untranslated leader sequence of a prokaryotic mRNA which serves as a ribosome binding site is called the _____ - _____ sequence.

9. Bacterial chromosomes, unlike eukaryotic chromosomes, often consist of a single replicon.

10. MRNA molecules have a nontranslated sequence called the __________ , which is located downstream of the termination codon.

11. Hershey and Chase demonstrated that when the bacteriophage T2 infected its host cell, the __________ is injected into the host but the __________ remained outside. (answer, answer)

12. Proteins that recognize unfolded polypeptides and help them fold into their proper conformations are called ______________.

13. DNA functions as a storage molecule, holding genetic information for the lifetime of a cellular organism and allowing that information to be duplicated and passed on to its progeny.

14. Initiation of translation in eukaryotes is similar to that in prokaryotes except that more initiation factors are required in eukaryotes.

15. The basic differences between RNA and DNA reside in their sugar and pyrimidine bases; RNA has ribose and uracil whereas DNA has deoxyribose and thymine.

16. In eukaryotes a so-called cap consisting of __________ is attached to the 5' end of the molecule during posttranscriptional modification of hnRNA to produce functional mRNA.

17. Splicing of eukaryotic heteronuclear RNA is catalyzed by ______________.

18. Eukaryotic mRNAs are modified by addition of a poly(A) sequences at the 3' end and 7-methyl guanosine at the 5' end.

19. The noncoding sequences located between the start codon and the stop codon in interrupted genes are called introns.

20. The B form of the DNA double helix contains a wider major groove and a narrower minor groove because the two polynucleotide strands are not positioned directly opposite one another in the helical cylinder.

21. The coding sequence in the DNA of __________ is normally continuous; that is, it is not interrupted by noncoding sequences.

22. The Y-shaped part of the DNA molecule where the actual replication process occurs is called the replication __________.

23. Which of the following nitrogenous bases is usually found in RNA but not in DNA?

24. The protein coding sequences in interrupted genes are called exons.

25. The portion of the tRNA molecule that binds to the codon on the mRNA is called the

26. The genetic information in DNA is divided into units called

27. When a DNA molecule is replicated, the daughter molecules contain one strand of parental DNA and one strand of newly synthesized DNA; this is called __________ replication.

28. The transcribed and translated region of a gene is the __________ region.

29. Some microbial proteins are spliced after translation in a reaction that results in removal of one or more internal intervening sequences called inteins.

30. The genetic code is usually translated in a nonoverlapping fashion.

31. Which of the following is not a termination codon?

32. Which of the following is not a complementary base pair usually found in DNA molecules?

33. The region at which the RNA polymerase binds is the __________ region.

34. In __________ ribosomes can attach to the mRNA and begin translation even though transcription has not been completed.

35. The chromosomes of most bacteria are comprised of

36. Posttranscriptional modifications that yield eukaryotic mRNAs include which of the following?

37. Which of the following is the initiator codon?

38. RNA polymerase II of eukaryotes is responsible for transcribing

39. During replication the 2 strands of the DNA molecule are unwound from one another by enzymes called

40. The expressed regions of split genes are called

41. The genetic code is translated in groups of __________ bases

42. ________ molecules deliver amino acids to ribosomes during translation.

43. Prokaryotic DNA replication occurs at a rate of

44. Split or interrupted genes have been found in eukaryotes but not in prokaryotes.

45. A complex consisting of a single mRNA molecule with several ribosomes is called a

46. The principle of transformation was first demonstrated by which of the following individuals or groups of individuals?

47. Which of the following is not a pyrimidine?

48. The strand of DNA for a particular gene that is copied by the RNA polymerase to form mRNA is called the __________ strand.

49. The genetic code is said to be __________ because more than one codon will specify a particular amino acid.

50. How many different termination codons are used in translation?

51. Ribosomes consist of __________ separate subunits that come together as part of the initiation process and dissociate immediately after termination.

52. Which of the following individuals or groups of individuals demonstrated that the transforming principle was DNA?

53. Over twisting or under twisting of helical DNA generates

54. Which of the following is true about the structure of DNA?

55. Which of the following is not considered the final product of the expression of a gene?

56. In eukaryotes a series of __________ residues are added to the 3' end of an RNA molecule as part of the posttranscriptional processing used to produce functional mRNA.

57. Key sequences exist within promoters, which vary somewhat among various promoters but are sufficiently constant that they can be represented by a sequence of bases most often found at each position. These representations are called __________ sequences.

58. The __________ reaction sequentially links adjacent amino acids into the growing polypeptide chain.

59. When RNA polymerase catalyzes the addition of a nucleotide to a growing mRNA chain, a byproduct of this reaction is

60. The energy needed for protein synthesis is provided by the hydrolysis of

61. The process by which the base sequence of all or a portion of a DNA molecule is used to direct the synthesis of an RNA molecule is called

62. What is the minimum number of aminoacyl-tRNA synthetase enzymes needed to attach amino acids to all the various tRNA molecules?

63. DNA replication is a complex process, and as a result the frequency of error is quite high.

64. The unexpressed regions of split genes are called

65. Because of its larger size, the replication rate of eukaryotic genomes is significantly faster than the replication rate of prokaryotic genomes.

66. In order to add a single amino acid to a growing polypeptide chain, a grand total of __________ molecules or ATP or GTP are utilized.

67. Each chromosome has one or more __________ site(s) where replication begins.

68. Which of the following is in the coding region of a gene?

69. A section of DNA that codes for a protein or other functional product is called a(n)

70. The Pribnow box of E. coli

71. The transcribed, but not translated, sequence that is immediately upstream of the region and encodes the functional product is called the __________ region.

72. The process by which the base sequence of an RNA molecule is used to direct the synthesis of a protein is called

73. RNA polymerase III of eukaryotes is responsible for transcribing

74. A bacterial __________ is the nontranscribed region of the DNA to which RNA polymerase binds in order to initiate transcription.

75. All prokaryotes initiate the synthesis of proteins with formylmethionine.

76. The stop codons are translated codons; that is, they specify amino acids to be inserted into the last position of a growing polypeptide chain.

5. Aminoacyl-tRNA synthetases catalyze covalent addition of to tRNAs. (2 words)

8. A consensus sequence in the untranslated leader sequence of a prokaryotic mRNA which serves as a ribosome binding site is called the _ - _ sequence.

11. Hershey and Chase demonstrated that when the bacteriophage T2 infected its host cell, the is injected into the host but the remained outside. (answer, answer)