Question 1

Which of the following is not associated with a bacterial ribosome?

Accepted Answer

A)   It is a 70s holoenzyme.
B)   It has a peptide (P)  site.
C)   It has an exit site.
D)   Its small subunit provides the enzymes for making peptide bonds.
E)   It has an amino acid (
A)   site.F) C) and E)
G) D) and E)

Question 2

Erythromcycin, a macrolide, inhibits protein synthesis _______.

Accepted Answer

A)   by binding to the ribosome, preventing translocation due to interference with the attachment of mRNA
B)   by preventing the formation of the initiation complex
C)   by interfering with both the initiation and elongation stages of translation
D)   by binding to the tRNA preventing peptide bond formation between amino acidsE) B) and C)
F) A) and D)

Question 3

Which of the following is not a type of microRNA?

Accepted Answer

A)   tRNA
B)   miRNA
C)   Antisense RNA
D)   Riboswitch
E)   siRNAF) B) and C)
G) B) and E)

Question 4

A bacteriophage transfers a random fragment of DNA of the previous host to the current host. This is an example of _______.

Accepted Answer

A)   conjugation
B)   generalized transduction
C)   specialized transduction
D)   the creation of an Hfr cellE) None of the above
F) All of the above

Question 5

The smallest unit of heredity is a chromosome.

Accepted Answer

A) True 
 B)False

Question 6

DNA Polymerase III _______.

Accepted Answer

A)   synthesizes the primer
B)   removes the primer
C)   joins Okazaki fragments
D)   unzips the DNA helix
E)   proofreads new DNAF) All of the above
G) None of the above

Question 7

The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called ________.

Accepted Answer

A)   ribosomal RNA
B)   messenger RNA
C)   transfer RNA
D)   primer RNA
E)   ribozymesF) A) and B)
G) A) and C)

Question 8

What type of mutation alters the base but not the amino acid being coded for?

Accepted Answer

A)   Silent
B)   Back
C)   Point
D)   Nonsense
E)   MissenseF) A) and D)
G) B) and D)

Question 9

Full induction of the lactose operon requires _______.

Accepted Answer

A)   lactose present
B)   lactose and glucose present
C)   lactose present without glucose
D)   lactose and arabinose presentE) A) and C)
F) All of the above

Question 10

Which of the following is not true of conjugation?

Accepted Answer

A)   Involves direct contact between cells
B)   Transfers genes for drug resistance
C)   Transfers genes for enzymes and adherence molecules
D)   Involves the action of bacteriophage
E)   The donor retains a copy of the transferred genesF) B) and D)
G) All of the above

Question 11

The duplication of a cell's DNA is called _______.

Accepted Answer

A)   mitosis
B)   replication
C)   transcription
D)   translation
E)   mutationF) B) and C)
G) A) and E) B

Question 12

The enzyme that helps pack DNA into the cell by coiling the DNA into a tight bundle is _______.

Accepted Answer

A)   DNA ligase
B)   DNA polymerase
C)   DNA helicase
D)   DNA gyrase
E)   primaseF) B) and C)
G) All of the above D

Question 13

Which is incorrect about purines?

Accepted Answer

A)   They are only found in DNA, not in RNA.
B)   They are nitrogenous bases.
C)   They are always paired with a speci?c pyrimidine.
D)   They include adenine and guanine.
E)   They are found within nucleotides.F) A) and E)
G) A) and C)

Question 14

Semiconservative replication refers to _______.

Accepted Answer

A)   each base bonding at the 1' position of the sugar
B)   a purine always bonding to a pyrimidine
C)   one helix strand that runs from the 5' to 3' direction and the other strand that runs from the 3' to 5' direction
D)   an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA moleculeE) A) and B)
F) A) and C)

Question 15

The enzyme that can proofread replicating DNA, detect incorrect bases, excise them, and correctly replace them is _______.

Accepted Answer

A)   DNA ligase
B)   DNA polymerase
C)   DNA helicase
D)   DNA gyrase
E)   primaseF) All of the above
G) A) and B)

Question 16

During replication, each parent DNA strand serves as a ______ for synthesis of new DNA strands.

Accepted Answer

A)   copy point
B)   template
C)   comparison molecule
D)   scaffold
E)   reservoirF) B) and D)
G) C) and D)

Question 17

Which is incorrect about inducible operons?

Accepted Answer

A)   They have genes turned off by a buildup of end product.
B)   They are often for use in catabolic pathways.
C)   They are normally turned off.
D)   They are turned on by the substrate of the enzyme.
E)   They include the lac operon.F) C) and E)
G) C) and D)

Question 18

The development of virulent, toxin-producing bacterial strains due to the presence of a temperate phage can occur through the process of ________.

Accepted Answer

A)   bacterial conjugation
B)   transformation
C)   generalized transduction
D)   specialized transductionE) A) and B)
F) None of the above

Question 19

Split genes _______.

Accepted Answer

A)   are common in bacteria and eukaryotes
B)   only have exons initially transcribed to mRNA
C)   have introns located only at the beginning and end of a coding region
D)   are acted upon by spliceosomes to excise introns and then join exonsE) B) and D)
F) All of the above

Question 20

Looking at your results of the Ames test using bacteriological agar medium plates lacking the amino acid histidine, you ?nd that there are many colonies growing on the agar. How do you interpret this result?

Accepted Answer

A)   The bacterium has turned its operon genes on, producing proteins necessary for growth.
B)   The chemical being tested is mutagenic.
C)   The bacterium does not have any plasmids, so it cannot grow on the medium.
D)   The drug being tested has no inhibitory effect on the bacterium; therefore, it is not a good antibiotic to give for treatment of disease.E) All of the above
F) A) and D) B

Exam 9: Microbial Genetics

Which of the following is not associated with a bacterial ribosome?

Correct AnswerverifiedShow Answer

Erythromcycin, a macrolide, inhibits protein synthesis _______.

Correct AnswerverifiedShow Answer

Which of the following is not a type of microRNA?

Correct AnswerverifiedShow Answer

A bacteriophage transfers a random fragment of DNA of the previous host to the current host. This is an example of _______.

Correct AnswerverifiedShow Answer

The smallest unit of heredity is a chromosome.

Correct AnswerverifiedShow Answer

DNA Polymerase III _______.

Correct AnswerverifiedShow Answer

The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called ________.

Correct AnswerverifiedShow Answer

What type of mutation alters the base but not the amino acid being coded for?

Correct AnswerverifiedShow Answer

Full induction of the lactose operon requires _______.

Correct AnswerverifiedShow Answer

Which of the following is not true of conjugation?

Correct AnswerverifiedShow Answer

The duplication of a cell's DNA is called _______.

Correct AnswerverifiedB

The enzyme that helps pack DNA into the cell by coiling the DNA into a tight bundle is _______.

Correct AnswerverifiedD

Which is incorrect about purines?

Correct AnswerverifiedShow Answer

Semiconservative replication refers to _______.

Correct AnswerverifiedShow Answer

The enzyme that can proofread replicating DNA, detect incorrect bases, excise them, and correctly replace them is _______.

Correct AnswerverifiedShow Answer

During replication, each parent DNA strand serves as a ______ for synthesis of new DNA strands.

Correct AnswerverifiedShow Answer

Which is incorrect about inducible operons?

Correct AnswerverifiedShow Answer

The development of virulent, toxin-producing bacterial strains due to the presence of a temperate phage can occur through the process of ________.

Correct AnswerverifiedShow Answer

Split genes _______.

Correct AnswerverifiedShow Answer

Looking at your results of the Ames test using bacteriological agar medium plates lacking the amino acid histidine, you ?nd that there are many colonies growing on the agar. How do you interpret this result?

Correct AnswerverifiedB

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B

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D

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B