Question 1

What are the differences between neutral mutations and silent mutations?

Accepted Answer

Neutral mutations and silent mutations a...

Question 2

Which of the following is the MOST common transposable element in humans?

Accepted Answer

A)   copia
B)   Alu
C)   Ac
D)   Ty
E)   PF) C) and E)
G) A) and E)

Question 3

Which of the following mutagens is MOST likely to cause a frameshift mutation?

Accepted Answer

A)   base analog
B)   alkylating agent
C)   intercalating agent
D)   ionizing radiation
E)   UV lightF) C) and D)
G) A) and B)

Question 4

Assume that a base-pair substitution mutation converts a DNA triplet (AAT)  to another DNA triplet (AAA) . A second mutation now changes the AAA triplet to the GAA triplet. (UUA and CUU code for leucine and UUU codes for phenylalanine.)  This second mutation is an example of a(n) :

Accepted Answer

A)   transversion.
B)   intragenic suppressor.
C)   loss-of-function mutation.
D)   intergenic suppressor.
E)   frameshift.F) B) and E)
G) A) and B)

Question 5

It is estimated that transposable elements compose approximately what percent of the human genome?

Accepted Answer

A)   
B)   1%
C)   10%
D)   50%
E)   99%F) B) and D)
G) None of the above

Question 6

Huntington's disease can strike at an earlier age and bring about a more rapid degeneration and death in successive generations within a family. This phenomenon can be explained by which mechanism?

Accepted Answer

A)   presence of a transposable element in the gene
B)   chronic exposure to mutagens in the environment
C)   expansion of a trinucleotide repeat in the coding sequence of the gene
D)   presence of an extra chromosome in the germ line
E)   absence of a gene product that is involved in DNA repairF) D) and E)
G) A) and B)

Question 7

Transposition can involve exchange of DNA sequences and recombination, which often leads to DNA:

Accepted Answer

A)   acetylation.
B)   rearrangements.
C)   condensation.
D)   repair.
E)   replication.F) B) and C)
G) None of the above

Question 8

Explain how UV light induces mutations in E. coli.

Accepted Answer

UV light induces mutations in E. coli by...

Question 9

To determine whether human exposure to radiation results in an increase in recessive mutations in the germ line, scientists can examine the sex ratio of children born to parents exposed to higher than normal radiation levels. Explain how and why the sex ratio might be affected by radiation exposure.

Accepted Answer

The sex ratio of children born to parent...

Question 10

How will the result of strand slippage on the newly synthesized strand differ from the result of strand slippage on the template strand?

Accepted Answer

The result of strand slippage on the new...

Question 11

The following nucleotide sequence is found in a short stretch of DNA: 5ʹ TGCC 3ʹ
3ʹ ACGG 5ʹ
Suppose a depurination event occurred within the top strand. If this mutant strand were used as a template for replication, what is the MOST likely sequence of the newly synthesized strand?

Accepted Answer

A)   3ʹ AAGG 5ʹ
B)   3ʹ TACC 5ʹ
C)   3ʹ AGGG 5ʹ
D)   3ʹ TTCC 5ʹ
E)   3ʹ AGG 5ʹF) None of the above
G) A) and D)

Question 12

What is the function of DNA glycosylases?

Accepted Answer

A)   to recognize and cleave phosphodiester bonds in DNA
B)   to recognize and remove modified bases from the sugar component of DNA
C)   to reattach the two parts of DNA that result from double-strand breaks
D)   to remove pyrimidine dimers from DNA of E. coli that result from exposure to UV light
E)   to prevent strand slippage during DNA replicationF) D) and E)
G) C) and E)

Question 13

Transposable elements that transpose through an RNA intermediate are retrotransposons. There are two types of retrotransposons: those that have direct repeats at each end, often called long terminal repeats (LTRs), and those that do not have these repeats. Pick an example of each type of retrotransposon and give (1) its basic structure and (2) its possible evolutionary history.

Accepted Answer

One example of a retrotransposon with lo...

Question 14

Helen has type I osteogenesis imperfecta (OI) , a genetic skeletal disorder. Shown below is her DNA sequence for a portion of the coding region of the collagen type I gene, which contains the mutation responsible for her disorder. The corresponding wild-type sequence is shown also (only one DNA strand is shown in each case) .  What type of mutation does Helen carry?

Accepted Answer

A)   missense
B)   nonsense
C)   silent
D)   deletion
E)   frameshiftF) C) and E)
G) B) and E)

Question 15

Which of the following is characteristic of retrotransposons?

Accepted Answer

A)   They use transposase to transpose to new sites.
B)   They have inverted repeats at each of their ends.
C)   They transpose through an RNA intermediate.
D)   They make transposase.
E)   They are found only in prokaryotes.F) None of the above
G) C) and E)

Question 16

What is the difference between a mutagen and a carcinogen?

Accepted Answer

A mutagen is a substance or agent that c...

Question 17

A mutation that changes a GC base pair to AT is a(n) :

Accepted Answer

A)   transition.
B)   transversion.
C)   induced mutation.
D)   missense mutation.
E)   synonymous mutation.F) A) and E)
G) C) and D)

Question 18

Strains of E. coli that are defective in mismatch repair have very high levels of spontaneous mutagenesis. Studies have shown that in wild-type strains A:C and G:T mispairings (as opposed to the normal A:T and G:C pairings)  that occur during DNA replication are more likely than other mispairings (A:G, etc.)  to be detected and repaired in these mismatch repair-proficient, wild-type strains. Which of the following types of base substitutions would you expect to be most common among the spectrum of spontaneous mutations created by the mutant mismatch repair-defective strains?

Accepted Answer

A)   A-to-C
B)   C-to-A
C)   G-to-C
D)   A-to-G
E)   A-to-TF) B) and E)
G) B) and D)

Question 19

Fragile-X syndrome is an example of a disease caused by what type of mutation?

Accepted Answer

A)   nonsense mutation
B)   frameshift mutation
C)   expanding nucleotide repeat
D)   loss-of-function mutation
E)   gain-of-function mutationF) C) and E)
G) C) and D)

Question 20

The disorder xeroderma pigmentosum is associated with a defect in what type of DNA repair system?

Accepted Answer

A)   mismatch repair
B)   base-excision repair
C)   photoreactivation
D)   nucleotide-excision repair
E)   homologous recombinationF) A) and B)
G) C) and D)

Exam 18: Gene Mutations and Dna Repair

Explain how UV light induces mutations in E. coli.

Correct Answer
Answered by ExamLex AI
UV light induces mutations in E. coli by...
View Answer

To determine whether human exposure to radiation results in an increase in recessive mutations in the germ line, scientists can examine the sex ratio of children born to parents exposed to higher than normal radiation levels. Explain how and why the sex ratio might be affected by radiation exposure.

Correct Answer
Answered by ExamLex AI
The sex ratio of children born to parent...
View Answer

How will the result of strand slippage on the newly synthesized strand differ from the result of strand slippage on the template strand?

Correct Answer
Answered by ExamLex AI
The result of strand slippage on the new...
View Answer

Which of the following mutagens is MOST likely to cause a frameshift mutation?

Correct Answer
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Correct Answer
Answered by ExamLex AI
One example of a retrotransposon with lo...
View Answer

Which of the following is the MOST common transposable element in humans?

Correct Answer
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It is estimated that transposable elements compose approximately what percent of the human genome?

Correct Answer
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Assume that a base-pair substitution mutation converts a DNA triplet (AAT) to another DNA triplet (AAA) . A second mutation now changes the AAA triplet to the GAA triplet. (UUA and CUU code for leucine and UUU codes for phenylalanine.) This second mutation is an example of a(n) :

Correct Answer
verified

The disorder xeroderma pigmentosum is associated with a defect in what type of DNA repair system?

Correct Answer
verified

Transposition can involve exchange of DNA sequences and recombination, which often leads to DNA:

Correct Answer
verified

Which of the following is characteristic of retrotransposons?

Correct Answer
verified

What is the difference between a mutagen and a carcinogen?

Correct Answer
Answered by ExamLex AI
A mutagen is a substance or agent that c...
View Answer

Fragile-X syndrome is an example of a disease caused by what type of mutation?

Correct Answer
verified

Correct Answer
verified

Correct Answer
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The following nucleotide sequence is found in a short stretch of DNA: 5ʹ TGCC 3ʹ 3ʹ ACGG 5ʹ Suppose a depurination event occurred within the top strand. If this mutant strand were used as a template for replication, what is the MOST likely sequence of the newly synthesized strand?

Correct Answer
verified

A mutation that changes a GC base pair to AT is a(n) :

Correct Answer
verified

What are the differences between neutral mutations and silent mutations?

Correct Answer
Answered by ExamLex AI
Neutral mutations and silent mutations a...
View Answer

What is the function of DNA glycosylases?

Correct Answer
verified

Huntington's disease can strike at an earlier age and bring about a more rapid degeneration and death in successive generations within a family. This phenomenon can be explained by which mechanism?

Correct Answer
verified

Exam 18: Gene Mutations and Dna Repair

Explain how UV light induces mutations in E. coli.

Correct AnswerAnswered by ExamLex AIUV light induces mutations in E. coli by...View AnswerShow Answer

Correct AnswerAnswered by ExamLex AIThe sex ratio of children born to parent...View AnswerShow Answer

How will the result of strand slippage on the newly synthesized strand differ from the result of strand slippage on the template strand?

Correct AnswerAnswered by ExamLex AIThe result of strand slippage on the new...View AnswerShow Answer

Which of the following mutagens is MOST likely to cause a frameshift mutation?

Correct AnswerverifiedShow Answer

Correct AnswerAnswered by ExamLex AIOne example of a retrotransposon with lo...View AnswerShow Answer

Which of the following is the MOST common transposable element in humans?

Correct AnswerverifiedShow Answer

It is estimated that transposable elements compose approximately what percent of the human genome?

Correct AnswerverifiedShow Answer

Assume that a base-pair substitution mutation converts a DNA triplet (AAT) to another DNA triplet (AAA) . A second mutation now changes the AAA triplet to the GAA triplet. (UUA and CUU code for leucine and UUU codes for phenylalanine.) This second mutation is an example of a(n) :

Correct AnswerverifiedShow Answer

The disorder xeroderma pigmentosum is associated with a defect in what type of DNA repair system?

Correct AnswerverifiedShow Answer

Transposition can involve exchange of DNA sequences and recombination, which often leads to DNA:

Correct AnswerverifiedShow Answer

Which of the following is characteristic of retrotransposons?

Correct AnswerverifiedShow Answer

What is the difference between a mutagen and a carcinogen?

Correct AnswerAnswered by ExamLex AIA mutagen is a substance or agent that c...View AnswerShow Answer

Fragile-X syndrome is an example of a disease caused by what type of mutation?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The following nucleotide sequence is found in a short stretch of DNA: 5ʹ TGCC 3ʹ 3ʹ ACGG 5ʹ Suppose a depurination event occurred within the top strand. If this mutant strand were used as a template for replication, what is the MOST likely sequence of the newly synthesized strand?

Correct AnswerverifiedShow Answer

A mutation that changes a GC base pair to AT is a(n) :

Correct AnswerverifiedShow Answer

What are the differences between neutral mutations and silent mutations?

Correct AnswerAnswered by ExamLex AINeutral mutations and silent mutations a...View AnswerShow Answer

What is the function of DNA glycosylases?

Correct AnswerverifiedShow Answer

Huntington's disease can strike at an earlier age and bring about a more rapid degeneration and death in successive generations within a family. This phenomenon can be explained by which mechanism?

Correct AnswerverifiedShow Answer

Correct Answer
Answered by ExamLex AI
UV light induces mutations in E. coli by...
View Answer

Correct Answer
Answered by ExamLex AI
The sex ratio of children born to parent...
View Answer

Correct Answer
Answered by ExamLex AI
The result of strand slippage on the new...
View Answer

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
One example of a retrotransposon with lo...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
A mutagen is a substance or agent that c...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
Answered by ExamLex AI
Neutral mutations and silent mutations a...
View Answer

Correct Answer
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Correct Answer
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