Question 1

In an F+ *F- mating,all or part of the host chromosome usually is transferred to the recipient.

Accepted Answer

A) True 
 B)False

Question 2

One strategy to overcome antibiotic resistance is to use the same antibiotics in animal husbandry as those that are prescribed for humans,since the potential for resistant bacteria to evolve would be limited to only a small number of drug classes.

Accepted Answer

A) True 
 B)False

Question 3

When assessing the role of conjugative bacteria in the spread of antibiotic resistance genes,it is fair to say that Hfr cells contribute most while F- cells contribute least.

Accepted Answer

A) True 
 B)False

Question 4

A microbiologist is working with two genera of bacteria,A and B,to determine if cells are competent.Strains are grown under optimal conditions,and DNA fragments that carry the gene for green fluorescent protein is added to each culture at 20-minute intervals.Samples from each treatment are plated to nutrient agar and incubated,after which the plates are examined under an ultraviolet lamp.The microbiologist observes that all plates of bacteria B contain colonies that are fluorescent,while for bacteria A only the plates from stationary phase demonstrate fluorescent colonies.What can be concluded from these results?

Accepted Answer

A) Both bacteria A and bacteria B cells are competent. 
B) Competence in bacteria A is constitutively expressed. 
C) Competence in bacteria B is dependent on the phase of growth. 
D) Neither bacteria A nor bacteria B cells are competent. 
A) Both bacteria A and bacteria B cells are competent. 
B) Competence in bacteria A is constitutively expressed. 
C) Competence in bacteria B is dependent on the phase of growth. 
D) Neither bacteria A nor bacteria B cells are competent.

Question 5

The __________ __________ is the most prevalent form of a gene in a population.

Accepted Answer

The answer of The __________ __________ is the most prevalent...

Question 6

A __________ mutation does not alter the amino acid sequence of the resulting protein.

Accepted Answer

A) missense 
B) nonsense 
C) silent 
D) None of the choices are correct. 
A) missense 
B) nonsense 
C) silent 
D) None of the choices are correct.

Question 7

A mutation that changes the amino acid sequence of the resulting protein by substitution is called a __________ mutation.

Accepted Answer

A) missense 
B) nonsense 
C) silent 
D) None of the choices are correct. 
A) missense 
B) nonsense 
C) silent 
D) None of the choices are correct.

Question 8

Complete transfer in an Hfr *F- mating takes approximately __________ minutes.

Accepted Answer

A) 20 
B) 50 
C) 100 
D) 200 
A) 20 
B) 50 
C) 100 
D) 200

Question 9

One possible fate for an exogenote is

Accepted Answer

A) integration into the host chromosome. 
B) independent replication and functioning. 
C) degradation to nucleotides. 
D) All of the choices are correct. 
A) integration into the host chromosome. 
B) independent replication and functioning. 
C) degradation to nucleotides. 
D) All of the choices are correct.

Question 10

In the mechanics of conjugation,exclusive of gene transfer,Hfr and F+ strains behave the same.

Accepted Answer

A) True 
 B)False

Question 11

During generalized transduction

Accepted Answer

A) the host chromosome is degraded into randomly sized fragments. 
B) any DNA fragment of the appropriate size is packaged. 
C) any bacterial gene may be transferred to the subsequent host. 
D) All of the choices are correct. 
A) the host chromosome is degraded into randomly sized fragments. 
B) any DNA fragment of the appropriate size is packaged. 
C) any bacterial gene may be transferred to the subsequent host. 
D) All of the choices are correct.

Question 12

A plasmid that can either exist independently of the chromosome or be integrated into it is called a(n)__________.

Accepted Answer

The answer of A plasmid that can either exist independently...

Question 13

Microbial strains that can grow on minimal medium are called __________.

Accepted Answer

A) autotrophs 
B) auxotrophs 
C) prototrophs 
D) minitrophs 
A) autotrophs 
B) auxotrophs 
C) prototrophs 
D) minitrophs

Question 14

A microbiologist is working with a bacteria strain to determine if cells are competent.Cells are grown under optimal conditions with DNA fragments that carry two genes,green fluorescent protein and ampicillin resistance,and then plated to nutrient agar with and without ampicillin.Following incubation,plates are examined for fluorescent colonies under a UV lamp.Predict the results if cells are competent.

Accepted Answer

A) Fluorescent colonies will be present on both types of plates. 
B) Fluorescent colonies will be present on the the ampicillin agar plates,but there will be no growth on the nutrient agar plates. 
C) Colonies will be present on both types of plates,but will only fluoresce on the ampicillin agar plates. 
D) There will be no growth on either type of plate. 
A) Fluorescent colonies will be present on both types of plates. 
B) Fluorescent colonies will be present on the the ampicillin agar plates,but there will be no growth on the nutrient agar plates. 
C) Colonies will be present on both types of plates,but will only fluoresce on the ampicillin agar plates. 
D) There will be no growth on either type of plate.

Question 15

Insertion sequences are

Accepted Answer

A) normally relatively short (700 to 1,650 bp). 
B) capable of transposition. 
C) are discrete genetic elements bounded at both ends with inverted repeats. 
D) All of the choices are correct. 
A) normally relatively short (700 to 1,650 bp). 
B) capable of transposition. 
C) are discrete genetic elements bounded at both ends with inverted repeats. 
D) All of the choices are correct.

Question 16

As pertaining to the spread of antibiotic resistance in bacteria,which of the following terms is not directly related to the others?

Accepted Answer

A) Intercalate 
B) Cassette 
C) Integron 
D) Integrase 
A) Intercalate 
B) Cassette 
C) Integron 
D) Integrase

Question 17

Which of the following is the most error-prone of the repair mechanisms?

Accepted Answer

A) Postreplication repair 
B) Recombination repair 
C) SOS repair 
D) Photoreactivation 
A) Postreplication repair 
B) Recombination repair 
C) SOS repair 
D) Photoreactivation

Question 18

Bacterial isolates from post surgical infections of several patients on the same hospital floor demonstrate an increase in resistance to similar antibiotics.The pattern of antibiotic resistance in these cases is most likely due to vertical gene transfer among bacteria that carry resistance genes to bacteria that lack those genes.

Accepted Answer

A) True 
 B)False

Question 19

An Hfr cell and an F- cell result from conjugation between a donor cell and a recipient cell.Which statement is false regarding this event?

Accepted Answer

A) The donor could have been either F- or F+. 
B) The donor could have been Hfr. 
C) The recipient could have been F-. 
D) The donor could not have been F-. 
A) The donor could have been either F- or F+. 
B) The donor could have been Hfr. 
C) The recipient could have been F-. 
D) The donor could not have been F-.

Question 20

If a region of DNA contained numerous mismatches due to a modifying agent that caused methylation of guanine,which of the following mutagens is most likely the cause?

Accepted Answer

A) A deaminating base such as nitrous oxide 
B) An intercalating agent such as acridine orange 
C) A DNA modifier such as an alkylating agent 
D) Ionizing energy such as gamma radiation 
A) A deaminating base such as nitrous oxide 
B) An intercalating agent such as acridine orange 
C) A DNA modifier such as an alkylating agent 
D) Ionizing energy such as gamma radiation

Exam 16: Mechanisms of Genetic Variation

In an F+ *F- mating,all or part of the host chromosome usually is transferred to the recipient.

One strategy to overcome antibiotic resistance is to use the same antibiotics in animal husbandry as those that are prescribed for humans,since the potential for resistant bacteria to evolve would be limited to only a small number of drug classes.

When assessing the role of conjugative bacteria in the spread of antibiotic resistance genes,it is fair to say that Hfr cells contribute most while F- cells contribute least.

The __________ __________ is the most prevalent form of a gene in a population.

A __________ mutation does not alter the amino acid sequence of the resulting protein.

A mutation that changes the amino acid sequence of the resulting protein by substitution is called a __________ mutation.

Complete transfer in an Hfr *F- mating takes approximately __________ minutes.

One possible fate for an exogenote is

In the mechanics of conjugation,exclusive of gene transfer,Hfr and F+ strains behave the same.

During generalized transduction

A plasmid that can either exist independently of the chromosome or be integrated into it is called a(n)__________.

Microbial strains that can grow on minimal medium are called __________.

Insertion sequences are

As pertaining to the spread of antibiotic resistance in bacteria,which of the following terms is not directly related to the others?

Which of the following is the most error-prone of the repair mechanisms?

An Hfr cell and an F- cell result from conjugation between a donor cell and a recipient cell.Which statement is false regarding this event?

If a region of DNA contained numerous mismatches due to a modifying agent that caused methylation of guanine,which of the following mutagens is most likely the cause?

The Evolution of Microorganisms and Microbiology

Microscopy

Bacterial Cell Structure

Archaeal Cell Structure

Eukaryotic Cell Structure

Viruses and Other Acellular Infectious Agents

Microbial Growth

Control of Microorganisms in the Environment

Antimicrobial Chemotherapy

Introduction to Metabolism

Catabolism: Energy Release and Conservation

Anabolism: the Use of Energy in Biosynthesis

Bacterial Genome Replication and Expression

Regulation of Bacterial Cellular Processes

Eukaryotic and Archaeal Genome Replication and Expression

Recombinant DNA Technology

Microbial Genomics

Microbial Taxonomy and the Evolution of Diversity

Archaea

The Deinococci, Mollicutes, and Nonproteobacterial Gram-Negative Bacteria

The Proteobacteria

Firmicutes: The Low G-C Gram-Positive Bacteria

Actinobacteria: the High G-C Gram-Positive Bacteria

Protists

Fungi Eumycota

Viruses

Biogeochemical Cycling and Global Climate Change

Methods in Microbial Ecology

Microorganisms in Marine and Freshwater Ecosystems

Microorganisms in Terrestrial Ecosystems

Microbial Interactions

Innate Host Resistance

Adaptive Immunity

Pathogenicity and Infection

Clinical Microbiology and Immunology

Epidemiology and Public Health Microbiology

Human Diseases Caused by Viruses and Prions

Human Diseases Caused by Bacteria

Human Diseases Caused by Fungi and Protists

Microbiology of Food

Biotechnology and Industrial Microbiology

Applied Environmental Microbiology

Filters

In an F⁺ *F^- mating,all or part of the host chromosome usually is transferred to the recipient.

When assessing the role of conjugative bacteria in the spread of antibiotic resistance genes,it is fair to say that Hfr cells contribute most while F^- cells contribute least.

The is the most prevalent form of a gene in a population.

Complete transfer in an Hfr *F^- mating takes approximately __________ minutes.

In the mechanics of conjugation,exclusive of gene transfer,Hfr and F⁺ strains behave the same.

An Hfr cell and an F^- cell result from conjugation between a donor cell and a recipient cell.Which statement is false regarding this event?