Question 1

A mutation has occurred during DNA replication while the cell was preparing to divide.As a result of this,the codon ACU of mRNA has now become ACC.Interestingly,there is no change to the protein being made.Why not?

Accepted Answer

A)  This is a silent mutation.
B)  The original amino acid isoleucine was changed to leucine,but they are the same variation of amino acid so no change to the protein.
C)  The mutation was fixed,and even though the codon is now ACC the correct amino acid is put into place for the normal protein.
D)  This is not a mutation that causes a big change,so there is no change to the protein being made.E) C) and D)
F) B) and D)

Question 2

Which of the following is incorrect about transfer RNA?

Accepted Answer

A)  has a bottom hairpin loop with an anticodon
B)  has an anticodon that is complementary to a codon
C)  contains a binding site for an amino acid
D)  the initiator tRNA that binds to the P site has the anticodon UAC
E)  initiator tRNA in bacteria carries tryptophanF) A) and D)
G) A) and E)

Question 3

Which of the following is not a type of bacterial DNA recombination?

Accepted Answer

A)  transformation
B)  conjugation
C)  mitosis
D)  transductionE) B) and C)
F) B) and D)

Question 4

A screening system called the _____ test is used for detecting chemicals with carcinogenic potential.

Accepted Answer

A)  Koch
B)  Ames
C)  mutation
D)  cancer
E)  IowaF) B) and D)
G) C) and E)

Question 5

DNA Polymerase I

Accepted Answer

A)  removes primers.
B)  adds bases to new DNA chain.
C)  seals DNA gaps.
D)  proofreads DNA chain.E) B) and D)
F) A) and D)

Question 6

The lactose repressor

Accepted Answer

A)  is transcribed with the structural lac genes.
B)  is activated by binding lactose.
C)  is inactivated by binding lactose.
D)  requires lactose for its transcription.E) B) and C)
F) A) and D)

Question 7

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) All of the above
G) D) and E)

Question 8

Eukaryotic chromosomes differ from prokaryotic chromosomes because only eukaryotes have

Accepted Answer

A)  histone proteins.
B)  chromosomes in a nucleus.
C)  several to many chromosomes.
D)  elongated,not circular,chromosomes.
E)  All of the choices are correct.F) C) and D)
G) D) and E)

Question 9

DNA polymerase III

Accepted Answer

A)  is needed for adding nucleotides during mRNA synthesis.
B)  synthesizes new DNA only in the 5' to 3' direction.
C)  cannot add nucleotides to the lagging strand.
D)  synthesizes an RNA primer.E) A) and B)
F) None of the above

Question 10

In Griffith's experiments with Streptococcus pneumoniae,rough nonencapsulated Streptococci were converted into smooth encapsulated Streptococci in the presence of the heat-killed smooth encapsulated Streptococci.Which microbial process had Griffith identified?

Accepted Answer

A)  transduction
B)  conjugation
C)  transformation
D)  cloningE) C) and D)
F) A) and C)

Question 11

Structural genes code for

Accepted Answer

A)  ribosomal RNA molecules.
B)  transfer RNA molecules.
C)  cellular proteins.
D)  gene expression elements.E) A) and B)
F) B) and D)

Question 12

Lactose is a corepressor in the lac operon.

Accepted Answer

A) True 
 B)False

Question 13

Gene regulation can involve a protein repressor that blocks _____ from initiating transcription.

Accepted Answer

A)  DNA polymerase I
B)  DNA polymerase III
C)  RNA polymerase
D)  mRNA
E)  rRNAF) A) and C)
G) A) and D)

Question 14

A frameshift is caused by ______ mutations.

Accepted Answer

A)  missense and insertion
B)  missense and nonsense
C)  nonsense and deletion
D)  deletion and insertion
E)  insertion and nonsenseF) B) and E)
G) A) and C)

Question 15

Microorganisms exhibit genomes contained on

Accepted Answer

A)  chromosomes.
B)  plasmids.
C)  mitochondrial DNA.
D)  chloroplast DNA.
E)  All of the choices are correct depending on the type of microorganism observed.F) B) and E)
G) A) and B)

Question 16

Introns have no detectable functions.

Accepted Answer

A) True 
 B)False

Question 17

A _____ is a specific segment of DNA that codes for the production of one functional product.

Accepted Answer

A)  intron
B)  exon
C)  gene
D)  operator
E)  tripletF) C) and E)
G) C) and D)

Question 18

In bacteria,initiator tRNA carries formyl methionine.

Accepted Answer

A) True 
 B)False

Question 19

If a codon for alanine is GCA,then the anticodon is

Accepted Answer

A)  GCA.
B)  CGT.
C)  ACG.
D)  CGU.
E)  UGC.F) C) and D)
G) B) and E)

Question 20

The antiparallel arrangement within DNA molecules 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 runs from the 3' to 5' direction.
D)  an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.E) B) and D)
F) B) and C)

Exam 9: Microbial Genetics

DNA Polymerase I

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The antiparallel arrangement within DNA molecules refers to

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Gene regulation can involve a protein repressor that blocks _____ from initiating transcription.

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A frameshift is caused by ______ mutations.

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Which of the following is incorrect about transfer RNA?

Correct AnswerverifiedShow Answer

The lactose repressor

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Eukaryotic chromosomes differ from prokaryotic chromosomes because only eukaryotes have

Correct AnswerverifiedShow Answer

In bacteria,initiator tRNA carries formyl methionine.

Correct AnswerverifiedShow Answer

Lactose is a corepressor in the lac operon.

Correct AnswerverifiedShow Answer

A screening system called the _____ test is used for detecting chemicals with carcinogenic potential.

Correct AnswerverifiedShow Answer

A mutation has occurred during DNA replication while the cell was preparing to divide.As a result of this,the codon ACU of mRNA has now become ACC.Interestingly,there is no change to the protein being made.Why not?

Correct AnswerverifiedShow Answer

In Griffith's experiments with Streptococcus pneumoniae,rough nonencapsulated Streptococci were converted into smooth encapsulated Streptococci in the presence of the heat-killed smooth encapsulated Streptococci.Which microbial process had Griffith identified?

Correct AnswerverifiedShow Answer

Structural genes code for

Correct AnswerverifiedShow Answer

Introns have no detectable functions.

Correct AnswerverifiedShow Answer

Which of the following is not a type of bacterial DNA recombination?

Correct AnswerverifiedShow Answer

DNA polymerase III

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If a codon for alanine is GCA,then the anticodon is

Correct AnswerverifiedShow Answer

A _____ is a specific segment of DNA that codes for the production of one functional product.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Microorganisms exhibit genomes contained on

Correct AnswerverifiedShow Answer

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