Question 1

Which DNA repair mechanism can be template-independent and require polymerase activity?

Accepted Answer

A)  Post-replication repair 
B)  Mismatch repair 
C)  Light-dependent repair 
D)  Error-prone repair 
E)  Excision repair 
A)  Post-replication repair 
B)  Mismatch repair 
C)  Light-dependent repair 
D)  Error-prone repair 
E)  Excision repair D

Question 2

Which of the following statements about the mismatch repair pathway is not correct?

Accepted Answer

A)  MutH contains a GATC-specific endonuclease activity 
B)  Cleavage of the unmethylated strand only occurs 3' to the mismatch 
C)  This system of repair utilizes MutH, MutL, MutS, and UvrD 
D)  The repair system can distinguish the template strand from the newly synthesized strand 
E)  All of these are correct 
A)  MutH contains a GATC-specific endonuclease activity 
B)  Cleavage of the unmethylated strand only occurs 3' to the mismatch 
C)  This system of repair utilizes MutH, MutL, MutS, and UvrD 
D)  The repair system can distinguish the template strand from the newly synthesized strand 
E)  All of these are correct B

Question 3

Living cells contain numerous enzymes that constantly scan DN,searching for damaged or incorrectly paired nucleotides.When detected,these defects are corrected by:

Accepted Answer

A)  DNA scanning enzymes 
B)  RNA polymerase 
C)  DNA repair enzymes 
D)  DNA polymerase 
E)  Ligase 
A)  DNA scanning enzymes 
B)  RNA polymerase 
C)  DNA repair enzymes 
D)  DNA polymerase 
E)  Ligase C

Question 4

Which of the following disease is not associated with a defect in a DNA repair pathway?

Accepted Answer

A)  Bloom syndrome 
B)  Werner syndrome 
C)  Rothmund-Thomson syndrome 
D)  Cystic Fibrosis 
E)  Fanconi anemia 
A)  Bloom syndrome 
B)  Werner syndrome 
C)  Rothmund-Thomson syndrome 
D)  Cystic Fibrosis 
E)  Fanconi anemia

Question 5

Which of the following molecules carries out single-strand assimilation?

Accepted Answer

A)  XPA 
B)  MutD 
C)  RecA 
D)  RecBCD 
E)  UvrD 
A)  XPA 
B)  MutD 
C)  RecA 
D)  RecBCD 
E)  UvrD

Question 6

Mutation is a random and non-adaptive process.This was first proven by:

Accepted Answer

A)  Lysenko and Lamarck, using the removal of mouse tails as an environmental stress. 
B)  Joshua and Esther Lederberg, using the removal of mouse tails as an environmental stress. 
C)  Lysenko and Lamarck, using replica plated E. coli and streptomycin as an environmental stress. 
D)  Joshua and Esther Lederberg, using replica-plated E. coli and streptomycin as an environmental stress 
E)  Mutation is not a random, nonadaptive process. 
A)  Lysenko and Lamarck, using the removal of mouse tails as an environmental stress. 
B)  Joshua and Esther Lederberg, using the removal of mouse tails as an environmental stress. 
C)  Lysenko and Lamarck, using replica plated E. coli and streptomycin as an environmental stress. 
D)  Joshua and Esther Lederberg, using replica-plated E. coli and streptomycin as an environmental stress 
E)  Mutation is not a random, nonadaptive process.

Question 7

X-shaped recombination intermediates formed from Holliday model recombination are known as:

Accepted Answer

A)  Tai molecules 
B)  Chi forms 
C)  Holliday forms 
D)  X forms 
E)  None of these 
A)  Tai molecules 
B)  Chi forms 
C)  Holliday forms 
D)  X forms 
E)  None of these

Question 8

Some mutagenic agents only affect replicating DNA; others are mutagenic to replicating and non-replicating DNA.Which of the following mutagens does not belong to the second class?

Accepted Answer

A)  Alkylating agents 
B)  Base analogs 
C)  Nitroud acid 
D)  All of these 
E)  None of these 
A)  Alkylating agents 
B)  Base analogs 
C)  Nitroud acid 
D)  All of these 
E)  None of these

Question 9

How do tautomeric shifts cause alterations in the pairing potential of nitrogenous bases?

Accepted Answer

Watson and Crick pointed out that the st

Question 10

Restoration of the wild type phenotype in a mutant organism can result from which of the following types of mutations?

Accepted Answer

A)  Back mutation 
B)  Suppressor mutation 
C)  Forward mutation 
D)  Back mutation and Suppressor mutation 
E)  Suppressor mutation and Forward mutation 
A)  Back mutation 
B)  Suppressor mutation 
C)  Forward mutation 
D)  Back mutation and Suppressor mutation 
E)  Suppressor mutation and Forward mutation

Question 11

Which of the following mutations is described correctly?

Accepted Answer

A)  Phenylketonuria: An autosomal recessive disease resulting in the overproduction of phenyalanine hydroxylase 
B)  Alkaptonuria: An autosomal recessive disease which inactivates homogentistic acid oxidase 
C)  Albinism: An autosomal dominant trait, which blocks the synthesis of melanin from tyrosine 
D)  Tyrosinemia: A lack of a tyrosine catabolic enzyme, which leads to an decrease in tyrosine in the blood and urine 
E)  All of these 
A)  Phenylketonuria: An autosomal recessive disease resulting in the overproduction of phenyalanine hydroxylase 
B)  Alkaptonuria: An autosomal recessive disease which inactivates homogentistic acid oxidase 
C)  Albinism: An autosomal dominant trait, which blocks the synthesis of melanin from tyrosine 
D)  Tyrosinemia: A lack of a tyrosine catabolic enzyme, which leads to an decrease in tyrosine in the blood and urine 
E)  All of these

Question 12

Which of the following organisms has never experienced a genetic mutation?

Accepted Answer

A)  E. coli 
B)  Humans 
C)  Drosophila 
D)  T4 virus 
E)  All of these have experienced genetic mutations 
A)  E. coli 
B)  Humans 
C)  Drosophila 
D)  T4 virus 
E)  All of these have experienced genetic mutations

Question 13

Which of the following is not exhibited Fragile X syndrome?

Accepted Answer

A)  An X chromosome which contains up to 1000 copies of the CCG repeat at one site 
B)  Inherited mental retardation 
C)  A correlation between the number of repeats and the severity of the defects 
D)  The phenomenon of "anticipation" 
E)  Decreasing numbers of the CCG repeat in successive generations 
A)  An X chromosome which contains up to 1000 copies of the CCG repeat at one site 
B)  Inherited mental retardation 
C)  A correlation between the number of repeats and the severity of the defects 
D)  The phenomenon of "anticipation" 
E)  Decreasing numbers of the CCG repeat in successive generations

Question 14

Which of the following statements about radiation induced mutations is true?

Accepted Answer

A)  X rays, cosmic rays, and UV rays are all classified as ionizing radiation 
B)  Ionizing radiation results in raising electrons to an atom's outer orbitals, a state referred to as excitation 
C)  In mammals, chronic irradiation is as effective in inducing mutations as acute irradiation 
D)  UV radiation results in the formation of purine dimers and purine hydrates 
E)  X rays can result in gross changes of chromosome structure, such as large deletions, duplications and inversions 
A)  X rays, cosmic rays, and UV rays are all classified as ionizing radiation 
B)  Ionizing radiation results in raising electrons to an atom's outer orbitals, a state referred to as excitation 
C)  In mammals, chronic irradiation is as effective in inducing mutations as acute irradiation 
D)  UV radiation results in the formation of purine dimers and purine hydrates 
E)  X rays can result in gross changes of chromosome structure, such as large deletions, duplications and inversions

Question 15

Which of the following mutations or techniques was not used in deducing the pathway of T4 morphogenesis?

Accepted Answer

A)  Auxitrophic mutations 
B)  Temperature-sensitive mutations 
C)  Suppressor-sensitive mutations 
D)  Electron micrsoscopy 
E)  Biochemical analysis 
A)  Auxitrophic mutations 
B)  Temperature-sensitive mutations 
C)  Suppressor-sensitive mutations 
D)  Electron micrsoscopy 
E)  Biochemical analysis

Question 16

Base-pair substitutions in which the purine in one strand of DNA is replaced with a different purine,and the pyrimidine in the complementary strand is replaced with a different pyrimidine are known as:

Accepted Answer

A)  Isomers 
B)  Transitions 
C)  Transversions 
D)  Inversions 
E)  None of these 
A)  Isomers 
B)  Transitions 
C)  Transversions 
D)  Inversions 
E)  None of these

Question 17

Which of the following proteins is vital to the process of recombination?

Accepted Answer

A)  RecA 
B)  CroA 
C)  HemA 
D)  Gyrase 
E)  Topoisomerase 
A)  RecA 
B)  CroA 
C)  HemA 
D)  Gyrase 
E)  Topoisomerase

Question 18

Mutations that involve changes at specific sites in a gene are referred to as:

Accepted Answer

A)  Frameshift mutations 
B)  Nonsense mutations 
C)  Misssense mutations 
D)  Point mutations 
E)  None of these 
A)  Frameshift mutations 
B)  Nonsense mutations 
C)  Misssense mutations 
D)  Point mutations 
E)  None of these

Question 19

Which of the following is a known mutagen?

Accepted Answer

A)  UV light 
B)  Thalidomide 
C)  Irradiation 
D)  UV light and Irradiation 
E)  All of these 
A)  UV light 
B)  Thalidomide 
C)  Irradiation 
D)  UV light and Irradiation 
E)  All of these

Question 20

What is the net effect of a tautomeric shift event,and the subsequent replication required to segregate the mismatched base pair? 1.A:T to G:C base pair substitution
2)G:C to A:T base pair substitution
3)A:C to G:T base pair substitution

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  All of these 
A)  1 
B)  2 
C)  3 
D)  1 and 2 
E)  All of these

Exam 13: Mutation,DNA Repair,And Recombination

Which DNA repair mechanism can be template-independent and require polymerase activity?

Which of the following statements about the mismatch repair pathway is not correct?

Living cells contain numerous enzymes that constantly scan DN,searching for damaged or incorrectly paired nucleotides.When detected,these defects are corrected by:

Which of the following disease is not associated with a defect in a DNA repair pathway?

Which of the following molecules carries out single-strand assimilation?

Mutation is a random and non-adaptive process.This was first proven by:

X-shaped recombination intermediates formed from Holliday model recombination are known as:

Some mutagenic agents only affect replicating DNA; others are mutagenic to replicating and non-replicating DNA.Which of the following mutagens does not belong to the second class?

How do tautomeric shifts cause alterations in the pairing potential of nitrogenous bases?

Restoration of the wild type phenotype in a mutant organism can result from which of the following types of mutations?

Which of the following mutations is described correctly?

Which of the following organisms has never experienced a genetic mutation?

Which of the following is not exhibited Fragile X syndrome?

Which of the following statements about radiation induced mutations is true?

Which of the following mutations or techniques was not used in deducing the pathway of T4 morphogenesis?

Base-pair substitutions in which the purine in one strand of DNA is replaced with a different purine,and the pyrimidine in the complementary strand is replaced with a different pyrimidine are known as:

Which of the following proteins is vital to the process of recombination?

Mutations that involve changes at specific sites in a gene are referred to as:

Which of the following is a known mutagen?

What is the net effect of a tautomeric shift event,and the subsequent replication required to segregate the mismatched base pair? 1.A:T to G:C base pair substitution 2)G:C to A:T base pair substitution 3)A:C to G:T base pair substitution

The Science Of Genetics

Cellular Reproduction

Mendelism The Basic Principles Of Inheritance

Extensions Of Mendelism

The Chromosomal Basis Of Mendelism

Variation In Chromosome Number And Structure

Linkage,Crossing Over,And Chromosome Mapping In …

The Genetics Of Bacteria And Their Viruses

DNA And The Molecular Structure Of Chromosomes

Replication Of DNA And Chromosomes

Transcription And RNA Processing

Translation And The Genetic Code

The Techniques Of Molecular Genetics

Genomics

Applications Of Molecular Genetics

Transposable Genetics Elements

Regulation Of Gene Expression In Prokaryotes

Regulation Of Gene Expression In Eukaryotes

The Genetic Control Of Animal Development

The Genetic Basis Of Cancer

Inheritance Of Complex Traits

Population Genetics

Evolutionary Genetics

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