Question 1

An example of a genetic disorder in humans that results from a loss-of-function mutation is:

Accepted Answer

A)  cystic fibrosis.
B)  achondroplasia.
C)  Huntington disease.
D)  myotonic dystrophy.
E)  None of the answers is correct.F) A) and E)
G) A) and B)

Question 2

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) A) and C)
G) B) and C)

Question 3

Transposable elements are found:

Accepted Answer

A)  mainly in higher plants.
B)  mainly in animals, particularly in mammals.
C)  mainly in eukaryotes.
D)  mainly in prokaryotes.
E)  in practically all organisms.F) A) and D)
G) B) and E)

Question 4

A codon for the amino acid serine undergoes a transversion so that it now codes for threonine.A transversion at a different site in the same codon then suppresses the first mutation.Give the nucleotides in the original codon, the transition mutation, and the transversion suppressor.(Note: There are two possible answers.)

Accepted Answer

AGC (serine)$\rightarrow$ACC (threonine)$\rightarrow$UCC (serine) AGU (serine)$\rightarrow$ ACU (threonine)$\rightarrow$ UCU (serine)

Question 5

Which of the following characterizes the mode of transposition of retrotransposons?

Accepted Answer

A)  It involves an RNA intermediate.
B)  It involves the initial synthesis of transposase.
C)  It involves the production of a protein repressor.
D)  It only occurs in nondividing host genomes.
E)  It requires inverted repeats at each end of the retrotransposon.F) A) and B)
G) A) and E)

Question 6

Most transposable elements are flanked by direct DNA repeats.What is the significance of these direct repeats?

Accepted Answer

The direct repeats indicate that stagger...

Question 7

What is an evolutionary consequence of transposable elements?

Accepted Answer

A)  Transposons play a large role in the expansion of eukaryotic genomes in size.
B)  Transposons are involved in extensive genome rearrangements.
C)  Transposon insertions can cause new DNA sequences that alter gene expression patterns.
D)  All of the answers are correct.
E)  None of the answers is correct.F) B) and E)
G) None of the above

Question 8

Which of the following is a form of direct DNA repair?

Accepted Answer

A)  Base-excision repair
B)  Nucleotide excision repair
C)  Homologous recombination
D)  Mismatch repair
E)  PhotoreactivationF) C) and D)
G) A) and E)

Question 9

Achondroplasia is a form of dwarfism that is inherited in humans as an autosomal dominant.A survey in a small country showed that, within a 2-year period, there were 12 children with normal parents born with this disorder out of a total of 420, 000 births.What is the mutation rate in mutations/locus/generation?

Accepted Answer

A)  1) 4 × 10-5
B)  2) 8 × 10-6
C)  2) 5 × 10-5
D)  2) 8 × 10-5
E)  7) 4 × 10-6F) C) and D)
G) D) and E) A

Question 10

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)  Reactivation
D)  Nucleotide-excision repair
E)  Homologous recombinationF) A) and B)
G) A) and C)

Question 11

Insertion or removal of one or more nucleotide base pairs in DNA within a gene often results in a _____ mutation.

Accepted Answer

A)  transition
B)  frameshift
C)  reversion
D)  transversion
E)  suppressorF) A) and B)
G) B) and D)

Question 12

Which of the following types of mutations does NOT lead to a change in the amino acid sequence of the gene product?

Accepted Answer

A)  Missense
B)  Nonsense
C)  Neutral
D)  Silent
E)  Loss-of-functionF) All of the above
G) C) and D)

Question 13

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) B) and D)
G) C) and E)

Question 14

How do intergenic and intragenic suppressor mutations differ?

Accepted Answer

Intergenic suppressor mutations are supp...

Question 15

What is the difference between a mutagen and a carcinogen?

Accepted Answer

A mutagen is any agent that causes an in...

Question 16

Which of the following statements about somatic mutations is FALSE?

Accepted Answer

A)  Some may give rise to cancers in humans and other animals.
B)  They may be inherited by daughter cells after cell division.
C)  They may result in inactive gene products of the mutated genes.
D)  They may result from both frameshift and base-pair substitution mutations.
E)  They may be inherited in the offspring of mutated individuals.F) All of the above
G) A) and E) E

Question 17

Assume that during DNA replication in a bacterium a mistake is made and a G is inserted into the newly synthesized DNA strand opposite a T in the template DNA strand.If this mistake is not repaired before the next round of DNA replication, what mutation will eventually result?

Accepted Answer

A)  A-to-G base substitution
B)  A-to-C base substitution
C)  A-to-T base substitution
D)  G-to-A base substitution
E)  C-to-A base substitutionF) All of the above
G) A) and C)

Question 18

The tinman mutation discovered in Drosophila is an example of how a geneticist can use mutants to study their effects on:

Accepted Answer

A)  gene expression.
B)  a biological system.
C)  missense mutations.
D)  genetic suppression.
E)  normal development.F) B) and D)
G) C) and E)

Question 19

Which of the following base changes in DNA is an example of a transition?

Accepted Answer

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

Question 20

Assume you are a geneticist and you're asked to examine the effects of a radiation leak that occurred at a facility in Iraq several years ago.How would you assess the level of mutations caused by this leak?

Accepted Answer

Compare the rates of cancer, gene mutati...

Exam 13: Gene Mutations, Transposable Elements, and Dna Repair

An example of a genetic disorder in humans that results from a loss-of-function mutation is:

Correct Answer
verified

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

Correct Answer
verified

Transposable elements are found:

Correct Answer
verified

Correct Answer
verified
AGC (serine)\(\rightarrow\)ACC (threonine)\(\rightarrow\)UCC (serine) AGU (serine)\(\rightarrow\) ACU (threonine)\(\rightarrow\) UCU (serine)

Which of the following characterizes the mode of transposition of retrotransposons?

Correct Answer
verified

Most transposable elements are flanked by direct DNA repeats.What is the significance of these direct repeats?

Correct Answer
verified
The direct repeats indicate that stagger...
View Answer

What is an evolutionary consequence of transposable elements?

Correct Answer
verified

Which of the following is a form of direct DNA repair?

Correct Answer
verified

Correct Answer
verified
A

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

Correct Answer
verified

Insertion or removal of one or more nucleotide base pairs in DNA within a gene often results in a _____ mutation.

Correct Answer
verified

Which of the following types of mutations does NOT lead to a change in the amino acid sequence of the gene product?

Correct Answer
verified

Which of the following is characteristic of retrotransposons?

Correct Answer
verified

How do intergenic and intragenic suppressor mutations differ?

Correct Answer
verified
Intergenic suppressor mutations are supp...
View Answer

What is the difference between a mutagen and a carcinogen?

Correct Answer
verified
A mutagen is any agent that causes an in...
View Answer

Which of the following statements about somatic mutations is FALSE?

Correct Answer
verified
E

Assume that during DNA replication in a bacterium a mistake is made and a G is inserted into the newly synthesized DNA strand opposite a T in the template DNA strand.If this mistake is not repaired before the next round of DNA replication, what mutation will eventually result?

Correct Answer
verified

The tinman mutation discovered in Drosophila is an example of how a geneticist can use mutants to study their effects on:

Correct Answer
verified

Which of the following base changes in DNA is an example of a transition?

Correct Answer
verified

Assume you are a geneticist and you're asked to examine the effects of a radiation leak that occurred at a facility in Iraq several years ago.How would you assess the level of mutations caused by this leak?

Correct Answer
verified
Compare the rates of cancer, gene mutati...
View Answer

Exam 13: Gene Mutations, Transposable Elements, and Dna Repair

An example of a genetic disorder in humans that results from a loss-of-function mutation is:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Transposable elements are found:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedAGC (serine)\(\rightarrow\)ACC (threonine)\(\rightarrow\)UCC (serine) AGU (serine)\(\rightarrow\) ACU (threonine)\(\rightarrow\) UCU (serine)

Which of the following characterizes the mode of transposition of retrotransposons?

Correct AnswerverifiedShow Answer

Most transposable elements are flanked by direct DNA repeats.What is the significance of these direct repeats?

Correct AnswerverifiedThe direct repeats indicate that stagger...View AnswerShow Answer

What is an evolutionary consequence of transposable elements?

Correct AnswerverifiedShow Answer

Which of the following is a form of direct DNA repair?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedA

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

Correct AnswerverifiedShow Answer

Insertion or removal of one or more nucleotide base pairs in DNA within a gene often results in a _____ mutation.

Correct AnswerverifiedShow Answer

Which of the following types of mutations does NOT lead to a change in the amino acid sequence of the gene product?

Correct AnswerverifiedShow Answer

Which of the following is characteristic of retrotransposons?

Correct AnswerverifiedShow Answer

How do intergenic and intragenic suppressor mutations differ?

Correct AnswerverifiedIntergenic suppressor mutations are supp...View AnswerShow Answer

What is the difference between a mutagen and a carcinogen?

Correct AnswerverifiedA mutagen is any agent that causes an in...View AnswerShow Answer

Which of the following statements about somatic mutations is FALSE?

Correct AnswerverifiedE

Assume that during DNA replication in a bacterium a mistake is made and a G is inserted into the newly synthesized DNA strand opposite a T in the template DNA strand.If this mistake is not repaired before the next round of DNA replication, what mutation will eventually result?

Correct AnswerverifiedShow Answer

The tinman mutation discovered in Drosophila is an example of how a geneticist can use mutants to study their effects on:

Correct AnswerverifiedShow Answer

Which of the following base changes in DNA is an example of a transition?

Correct AnswerverifiedShow Answer

Assume you are a geneticist and you're asked to examine the effects of a radiation leak that occurred at a facility in Iraq several years ago.How would you assess the level of mutations caused by this leak?

Correct AnswerverifiedCompare the rates of cancer, gene mutati...View AnswerShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
AGC (serine)\(\rightarrow\)ACC (threonine)\(\rightarrow\)UCC (serine) AGU (serine)\(\rightarrow\) ACU (threonine)\(\rightarrow\) UCU (serine)

Correct Answer
verified

Correct Answer
verified
The direct repeats indicate that stagger...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Intergenic suppressor mutations are supp...
View Answer

Correct Answer
verified
A mutagen is any agent that causes an in...
View Answer

Correct Answer
verified
E

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Compare the rates of cancer, gene mutati...
View Answer