Question 1

Sickle-cell anemia results from what type of mutation?

Accepted Answer

A)  silent
B)  missense
C)  nonsense
D)  frameshift
E)  base pair deletionF) A) and D)
G) D) and E)

Question 2

Each curve in the graph below shows the proportion of amino acid differences between a protein in two species that diverged from a common ancestral species. Which curve represents what would be expected if the protein were evolving according to a molecular clock?

Accepted Answer

A)  curve M
B)  curve H
C)  curve K
D)  curve L
E)  curve QF) B) and E)
G) C) and D)

Question 3

Only germ-line mutations are transmitted to the progeny.

Accepted Answer

A) True 
 B)False

Question 4

Depurination is a type of mutation where a purine base is lost, but the DNA backbone remains intact. Which of the following are likely to occur as a result of depurination?

Accepted Answer

A)  An incorrect base can be incorporated in the next round of replication.
B)  A deletion will occur, and there will be an overall loss of a base to the DNA strand.
C)  Repair enzymes will recognize the error and replace the defective nucleotide.
D)  An incorrect base can be incorporated in the next round of replication, and repair enzymes will recognize the error and replace the defective nucleotide.
E)  All of these choices are correct.F) A) and D)
G) B) and D)

Question 5

The enzyme _____ repairs breaks in the DNA sugar-phosphate backbone.

Accepted Answer

A)  DNA ligase
B)  DNA polymerase
C)  AP endonuclease
D)  uracyl glycosylase
E)  None of the other answer options is correct.F) D) and E)
G) A) and E)

Question 6

Why do RNA viruses and retroviruses have such high rates of mutation?

Accepted Answer

A)  because RNA polymerase is an unstable enzyme
B)  because RNA viruses and retroviruses initially cause host-cell mutations during replication
C)  because RNA is more fragile than DNA and is therefore more likely to be damaged
D)  because viral polymerases lack a proofreading mechanism
E)  because viral RNA can form stem-and-loop structuresF) None of the above
G) D) and E)

Question 7

Consider the tryptophan codon 5-UGG-3 in the standard genetic code (Table 4.1, shown below) . Can a single base change in this codon create a synonymous mutation? Can a single base change in this codon create a nonsense codon? -UGG-3 in the standard genetic code (Table 4.1, shown below) . Can a single base change in this codon create a synonymous mutation? Can a single base change in this codon create a nonsense codon?   A) yes; yes B) yes; no C) no; yes D) no; no" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  yes; yes
B)  yes; no
C)  no; yes
D)  no; noE) B) and C)
F) C) and D)

Question 8

The definition of mutation is "any heritable change in the genetic material." The qualifier "heritable" is necessary because:

Accepted Answer

A)  most changes in the genetic material are harmful to the organism.
B)  changes in the genetic material occur at random along the genome.
C)  changes in the genetic material occur without regard to the needs of the organism.
D)  most changes in the genetic material are repaired soon after they occur.E) A) and B)
F) A) and C)

Question 9

In the standard genetic code (Table 4.1, shown below) , what fraction of codons are nonsense codons?

Accepted Answer

A)  1/64
B)  2/64
C)  3/64
D)  4/64
E)  5/64F) B) and E)
G) C) and D)

Question 10

Which of the following enzymes is responsible for initiating certain types of base excision repair?

Accepted Answer

A)  DNA polymerase
B)  DNA ligase
C)  AP endonuclease
D)  DNA uracil glycosylase
E)  None of the other answer options is correct.F) All of the above
G) A) and B)

Question 11

The accompanying diagram shows three gene duplication events that gave rise to a gene family consisting of four sequences X1- X4. A researcher sequences the genes in two related species and discovers that each species has two copies. One species has copies X1 and X2, and the other has copies X3 and X4. The sequence of X1 is very close to that of X2, and the sequence of X3 is very close to that of X4; however, the (X1, X2)  pair is quite dissimilar from the (X3, X4)  pair. The most likely interpretation of this pattern is that speciation took place in the interval labeled: 1- X4. A researcher sequences the genes in two related species and discovers that each species has two copies. One species has copies X1 and X2, and the other has copies X3 and X4. The sequence of X1 is very close to that of X2, and the sequence of X3 is very close to that of X4; however, the (X1, X2)  pair is quite dissimilar from the (X3, X4)  pair. The most likely interpretation of this pattern is that speciation took place in the interval labeled:   A) M)  B) H)  C) K)  D) None of the answer options is correct." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  M) 
B)  H) 
C)  K) 
D)  None of the answer options is correct.E) B) and C)
F) None of the above

Question 12

Any DNA "damage" is considered to be a mutation, even if it is immediately corrected by the action of DNA polymerase.

Accepted Answer

A) True 
 B)False

Question 13

A mutation consisting of a single-nucleotide deletion creates a frameshift in a long open reading frame. In the shifted reading frame, what is the expected average number of codons before a nonsense codon is encountered? (Round any fraction to the nearest whole number.)

Accepted Answer

A)  11
B)  13
C)  16
D)  21
E)  32F) C) and D)
G) A) and D)

Question 14

Incorrectly repaired double-stranded breaks in DNA can produce:

Accepted Answer

A)  duplications.
B)  deletions.
C)  inversions.
D)  translocations.
E)  All of these choices are correct.F) B) and C)
G) A) and C)

Question 15

_____ is the process where new genes evolve from duplicates of old ones.

Accepted Answer

A)  Duplication and divergence
B)  Inversion
C)  Reciprocal translocation
D)  Deletion
E)  Centromere dosageF) B) and E)
G) A) and B)

Question 16

Loss of a pyrimidine base is one of the most common types of DNA damage.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following statements applies to frameshift mutations?

Accepted Answer

A)  They cause the insertion or deletion of a single amino acid from the polypeptide chain.
B)  They create a premature stop codon at the site of mutation.
C)  They change the amino acid sequence downstream from the mutant site.
D)  They are known risk factors in most forms of cancer, including breast and colon cancer.
E)  They are known risk factors in breast cancer, but not colon cancer.F) None of the above
G) A) and B)

Question 18

In the standard genetic code, how many amino acids have codons that allow synonymous mutations in the first position?

Accepted Answer

A)  0
B)  2
C)  8
D)  16
E)  20F) B) and D)
G) A) and E)

Question 19

A nonsense mutation:

Accepted Answer

A)  changes the identity of one amino acid in a polypeptide chain.
B)  shifts the reading frame of a messenger RNA.
C)  is usually due to a nucleotide substitution in the third position of a codon.
D)  changes a codon for an amino acid into a codon for chain termination.E) All of the above
F) A) and D)

Question 20

Any deviation in normal gene dosage is lethal.

Accepted Answer

A) True 
 B)False

Exam 14: Mutation and Dna Repair

Which of the following statements applies to frameshift mutations?

Correct Answer
verified

In the standard genetic code (Table 4.1, shown below) , what fraction of codons are nonsense codons? $In the standard genetic code (Table 4.1, shown below) , what fraction of codons are nonsense codons? A) 1/64 B) 2/64 C) 3/64 D) 4/64 E) 5/64$

Correct Answer
verified

The definition of mutation is "any heritable change in the genetic material." The qualifier "heritable" is necessary because:

Correct Answer
verified

_____ is the process where new genes evolve from duplicates of old ones.

Correct Answer
verified

In the standard genetic code, how many amino acids have codons that allow synonymous mutations in the first position?

Correct Answer
verified

Depurination is a type of mutation where a purine base is lost, but the DNA backbone remains intact. Which of the following are likely to occur as a result of depurination?

Correct Answer
verified

Correct Answer
verified

Incorrectly repaired double-stranded breaks in DNA can produce:

Correct Answer
verified

Only germ-line mutations are transmitted to the progeny.

Correct Answer
verified

Any DNA "damage" is considered to be a mutation, even if it is immediately corrected by the action of DNA polymerase.

Correct Answer
verified

Which of the following enzymes is responsible for initiating certain types of base excision repair?

Correct Answer
verified

Loss of a pyrimidine base is one of the most common types of DNA damage.

Correct Answer
verified

Each curve in the graph below shows the proportion of amino acid differences between a protein in two species that diverged from a common ancestral species. Which curve represents what would be expected if the protein were evolving according to a molecular clock?

Correct Answer
verified

Sickle-cell anemia results from what type of mutation?

Correct Answer
verified

Consider the tryptophan codon 5-UGG-3 in the standard genetic code (Table 4.1, shown below) . Can a single base change in this codon create a synonymous mutation? Can a single base change in this codon create a nonsense codon?

Correct Answer
verified

Any deviation in normal gene dosage is lethal.

Correct Answer
verified

A nonsense mutation:

Correct Answer
verified

A mutation consisting of a single-nucleotide deletion creates a frameshift in a long open reading frame. In the shifted reading frame, what is the expected average number of codons before a nonsense codon is encountered? (Round any fraction to the nearest whole number.)

Correct Answer
verified

Why do RNA viruses and retroviruses have such high rates of mutation?

Correct Answer
verified

The enzyme _____ repairs breaks in the DNA sugar-phosphate backbone.

Correct Answer
verified

Exam 14: Mutation and Dna Repair

Which of the following statements applies to frameshift mutations?

Correct AnswerverifiedShow Answer

In the standard genetic code (Table 4.1, shown below) , what fraction of codons are nonsense codons?

Correct AnswerverifiedShow Answer

The definition of mutation is "any heritable change in the genetic material." The qualifier "heritable" is necessary because:

Correct AnswerverifiedShow Answer

_____ is the process where new genes evolve from duplicates of old ones.

Correct AnswerverifiedShow Answer

In the standard genetic code, how many amino acids have codons that allow synonymous mutations in the first position?

Correct AnswerverifiedShow Answer

Depurination is a type of mutation where a purine base is lost, but the DNA backbone remains intact. Which of the following are likely to occur as a result of depurination?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Incorrectly repaired double-stranded breaks in DNA can produce:

Correct AnswerverifiedShow Answer

Only germ-line mutations are transmitted to the progeny.

Correct AnswerverifiedShow Answer

Any DNA "damage" is considered to be a mutation, even if it is immediately corrected by the action of DNA polymerase.

Correct AnswerverifiedShow Answer

Which of the following enzymes is responsible for initiating certain types of base excision repair?

Correct AnswerverifiedShow Answer

Loss of a pyrimidine base is one of the most common types of DNA damage.

Correct AnswerverifiedShow Answer

Each curve in the graph below shows the proportion of amino acid differences between a protein in two species that diverged from a common ancestral species. Which curve represents what would be expected if the protein were evolving according to a molecular clock?

Correct AnswerverifiedShow Answer

Sickle-cell anemia results from what type of mutation?

Correct AnswerverifiedShow Answer

Consider the tryptophan codon 5-UGG-3 in the standard genetic code (Table 4.1, shown below) . Can a single base change in this codon create a synonymous mutation? Can a single base change in this codon create a nonsense codon?

Correct AnswerverifiedShow Answer

Any deviation in normal gene dosage is lethal.

Correct AnswerverifiedShow Answer

A nonsense mutation:

Correct AnswerverifiedShow Answer

A mutation consisting of a single-nucleotide deletion creates a frameshift in a long open reading frame. In the shifted reading frame, what is the expected average number of codons before a nonsense codon is encountered? (Round any fraction to the nearest whole number.)

Correct AnswerverifiedShow Answer

Why do RNA viruses and retroviruses have such high rates of mutation?

Correct AnswerverifiedShow Answer

The enzyme _____ repairs breaks in the DNA sugar-phosphate backbone.

Correct AnswerverifiedShow Answer

Correct Answer
verified

In the standard genetic code (Table 4.1, shown below) , what fraction of codons are nonsense codons? $In the standard genetic code (Table 4.1, shown below) , what fraction of codons are nonsense codons? A) 1/64 B) 2/64 C) 3/64 D) 4/64 E) 5/64$

Correct Answer
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