Question 1

Approximately what percentage of the 4,288 open reading frames of E. coli have no known or annotated function?

Accepted Answer

A)  10 
B)  14 
C)  24 
D)  52 
E)  70 
A)  10 
B)  14 
C)  24 
D)  52 
E)  70 C

Question 2

What is transcription-coupled repair and why is it important for the cell?

Accepted Answer

Transcriptionally active genes that are damaged need to be repaired. A cell unable to transcribe a gene due to recent DNA damage will be at an extreme disadvantage. The nucleotide excision repair mechanism is used. A protein recognizes a stalled RNA pol and UvrAB is hijacked to begin the repair process.

Question 3

Why does a genetic experiment using recombination generally involve screening hundreds of millions of cells to find a few recombinants that form visible colonies?

Accepted Answer

The whole process of recombination is very random and typically of low efficiency. A bacterium first has to receive the appropriate piece of DNA, and then it must recombine the right portion of it to reap any benefit.

Question 4

Which of the following is the activator of the SOS response?

Accepted Answer

A)  RecA 
B)  LexA 
C)  FtsZ 
D)  sulA 
E)  uvrA 
A)  RecA 
B)  LexA 
C)  FtsZ 
D)  sulA 
E)  uvrA

Question 5

The experiment outlined below is a/an ________ test. The role of the rat liver homogenate is to ________.

Accepted Answer

A)  pathogenicity; provide growth factors such as amino acids that the pathogen may require 
B)  pathogenicity; chemically modify the test chemical 
C)  Ames; control for spontaneous mutations 
D)  Ames; provide growth factors such as amino acids that the pathogen may require 
E)  Ames; chemically modify the test chemical 
A)  pathogenicity; provide growth factors such as amino acids that the pathogen may require 
B)  pathogenicity; chemically modify the test chemical 
C)  Ames; control for spontaneous mutations 
D)  Ames; provide growth factors such as amino acids that the pathogen may require 
E)  Ames; chemically modify the test chemical

Question 6

Spontaneous mutations can be caused by

Accepted Answer

A)  tautomers having altered base pairings. 
B)  acridine intercalating into DNA. 
C)  UV causing pyrimidine dimers. 
D)  5-bromouracil. 
E)  alkylating agents. 
A)  tautomers having altered base pairings. 
B)  acridine intercalating into DNA. 
C)  UV causing pyrimidine dimers. 
D)  5-bromouracil. 
E)  alkylating agents.

Question 7

Numerous human genetic diseases are caused by mutations in homologs of bacterial

Accepted Answer

A)  transposons. 
B)  ligases. 
C)  integrases. 
D)  polymerases. 
E)  repair genes. 
A)  transposons. 
B)  ligases. 
C)  integrases. 
D)  polymerases. 
E)  repair genes.

Question 8

The figure shown below diagrams a variety of genomic islands. What characteristics do these islands in the diagram share?

Accepted Answer

A)  They code for pathogenicity. 
B)  They are coded on transposons. 
C)  They have a GC content similar to the rest of the genome. 
D)  They encode type II secretion systems. 
E)  They have direct repeats and mostly insert near a tRNA gene. 
A)  They code for pathogenicity. 
B)  They are coded on transposons. 
C)  They have a GC content similar to the rest of the genome. 
D)  They encode type II secretion systems. 
E)  They have direct repeats and mostly insert near a tRNA gene.

Question 9

Ames used his reversion test with Salmonella to screen compounds for

Accepted Answer

A)  virulence. 
B)  pathogenicity. 
C)  toxicity. 
D)  antibiotics. 
E)  mutagenicity. 
A)  virulence. 
B)  pathogenicity. 
C)  toxicity. 
D)  antibiotics. 
E)  mutagenicity.

Question 10

The process of moving a genetic element within or between DNA molecules is

Accepted Answer

A)  conjugation. 
B)  transduction. 
C)  transformation. 
D)  transposition. 
E)  reversion. 
A)  conjugation. 
B)  transduction. 
C)  transformation. 
D)  transposition. 
E)  reversion.

Question 11

Agrobacterium can transfer DNA to ________ using its ________.

Accepted Answer

A)  E. coli; LINES 
B)  E. coli; Ti plasmid 
C)  plants; LINES 
D)  plants; Ti plasmid 
E)  plants; opines 
A)  E. coli; LINES 
B)  E. coli; Ti plasmid 
C)  plants; LINES 
D)  plants; Ti plasmid 
E)  plants; opines

Question 12

Approximately what percentage of the genome of E. coli O157:H7, which has been responsible for several outbreaks of food-borne disease, has been acquired from other species?

Accepted Answer

A)  5 
B)  10 
C)  25 
D)  40 
E)  50 
A)  5 
B)  10 
C)  25 
D)  40 
E)  50

Question 13

Compare and contrast general and site-specific recombination.

Accepted Answer

New pieces of DNA entering a cell, or DN

Question 14

Describe four of the error-proof DNA repair mechanisms.

Accepted Answer

Any four of the following are acceptable

Question 15

Consider a culture of 10,000 cells that double to 20,000 cells. If measuring 100 mutations in the population, the mutation frequency would be

Accepted Answer

A)  100 mutations / ~4,500 genes = 0.022. 
B)  100 mutations / 1 generation = 100. 
C)  100 mutations / 20,000 cells = 0.05. 
D)  100 mutations / 10,000 new cells = 0.001. 
E)  (100 / ~4,500 genes) / 10,000 new cells = 0.0000022. 
A)  100 mutations / ~4,500 genes = 0.022. 
B)  100 mutations / 1 generation = 100. 
C)  100 mutations / 20,000 cells = 0.05. 
D)  100 mutations / 10,000 new cells = 0.001. 
E)  (100 / ~4,500 genes) / 10,000 new cells = 0.0000022.

Question 16

What are the differences between replicative and nonreplicative transposition?

Accepted Answer

In nonreplicative transposition, the tra

Question 17

The reaction of cytosine, shown below, happens ________ and causes ________.

Accepted Answer

A)  spontaneously; pyrimidine dimers 
B)  when irradiated; pyrimidine dimers 
C)  when treated with acridine; pyrimidine dimers 
D)  when irradiated; transition mutations 
E)  spontaneously; transition mutations 
A)  spontaneously; pyrimidine dimers 
B)  when irradiated; pyrimidine dimers 
C)  when treated with acridine; pyrimidine dimers 
D)  when irradiated; transition mutations 
E)  spontaneously; transition mutations

Question 18

Is an Hfr cell also considered to be F⁺? Why or why not?

Accepted Answer

An Hfr cell has the F plasmid integrated

Question 19

In order to transfer, an F factor must have which of the following?

Accepted Answer

A)  oriV and its own DNA polymerase 
B)  oriV and tra genes 
C)  oriT and tra genes 
D)  oriT and its own DNA polymerase 
E)  oriT, tra genes, and its own DNA polymerase 
A)  oriV and its own DNA polymerase 
B)  oriV and tra genes 
C)  oriT and tra genes 
D)  oriT and its own DNA polymerase 
E)  oriT, tra genes, and its own DNA polymerase

Question 20

Why did Ames modify the test to incorporate treatment of the potential mutagen with rat liver extract?

Accepted Answer

The Ames test is used to determine if a

Exam 9: Gene Transfer, Mutations, and Genome Evolution

Approximately what percentage of the 4,288 open reading frames of E. coli have no known or annotated function?

What is transcription-coupled repair and why is it important for the cell?

Why does a genetic experiment using recombination generally involve screening hundreds of millions of cells to find a few recombinants that form visible colonies?

Which of the following is the activator of the SOS response?

The experiment outlined below is a/an ________ test. The role of the rat liver homogenate is to ________.

Spontaneous mutations can be caused by

Numerous human genetic diseases are caused by mutations in homologs of bacterial

The figure shown below diagrams a variety of genomic islands. What characteristics do these islands in the diagram share?

Ames used his reversion test with Salmonella to screen compounds for

The process of moving a genetic element within or between DNA molecules is

Agrobacterium can transfer DNA to ________ using its ________.

Approximately what percentage of the genome of E. coli O157:H7, which has been responsible for several outbreaks of food-borne disease, has been acquired from other species?

Compare and contrast general and site-specific recombination.

Describe four of the error-proof DNA repair mechanisms.

Consider a culture of 10,000 cells that double to 20,000 cells. If measuring 100 mutations in the population, the mutation frequency would be

What are the differences between replicative and nonreplicative transposition?

The reaction of cytosine, shown below, happens ________ and causes ________.

Is an Hfr cell also considered to be F⁺? Why or why not?

In order to transfer, an F factor must have which of the following?

Why did Ames modify the test to incorporate treatment of the potential mutagen with rat liver extract?

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

Viruses

Genomes and Chromosomes

Transcription, Translation, and Bioinformatics

Molecular Regulation

Viral Molecular Biology

Biotechniques and Synthetic Biology

Energetics and Catabolism

Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

Biosynthesis

Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

Filters

The experiment outlined below is a/an test. The role of the rat liver homogenate is to .

Agrobacterium can transfer DNA to using its .

The reaction of cytosine, shown below, happens and causes .