Question 1

If the att site of Escherichia coli was dissimilar to that of lambda phage due to a mutation,how would transduction be affected?

Accepted Answer

A) Phage DNA would be unable to integrate into host DNA. 
B) Lambda phage would be unable to package host DNA. 
C) Specialized transduction would become generalized. 
D) Transduction would not be affected since mutation is only in the host cell. 
A) Phage DNA would be unable to integrate into host DNA. 
B) Lambda phage would be unable to package host DNA. 
C) Specialized transduction would become generalized. 
D) Transduction would not be affected since mutation is only in the host cell.

Question 2

Host __________ is the process by which some cells are capable of degrading an exogenote.

Accepted Answer

The answer of Host __________ is the process by which...

Question 3

Predict the outcome of an F+ to F- mating if the F+ cell lacked a functional tra operon.

Accepted Answer

A) Upon entering the recipient,the F factor would be unable to integrate into to host chromosome. 
B) Conjugation would not occur because there would be no contact between the F+ and F- cells. 
C) Conjugation would occur,but the F- recipient could not become Hfr. 
D) There would be no effect on conjugation. 
A) Upon entering the recipient,the F factor would be unable to integrate into to host chromosome. 
B) Conjugation would not occur because there would be no contact between the F+ and F- cells. 
C) Conjugation would occur,but the F- recipient could not become Hfr. 
D) There would be no effect on conjugation.

Question 4

Mutations that result in the death of an organism when expressed are called __________ mutations.

Accepted Answer

A) dominant 
B) recessive 
C) lethal 
D) conditional 
A) dominant 
B) recessive 
C) lethal 
D) conditional

Question 5

Alternate forms of genes resulting from mutations are called

Accepted Answer

A) isoforms. 
B) alterons. 
C) alleles. 
D) lethal. 
A) isoforms. 
B) alterons. 
C) alleles. 
D) lethal.

Question 6

A microbial geneticist observes that a significant number of pyrimidine dimers are present in bacterial DNA following exposure to a particular mutagen.To which mutagen were the bacterial cells likely exposed?

Accepted Answer

A) UV light 
B) Acridine orange 
C) 5-bromouracil 
D) X-rays 
A) UV light 
B) Acridine orange 
C) 5-bromouracil 
D) X-rays

Question 7

Specialized transduction can be carried out by

Accepted Answer

A) any bacteriophage. 
B) any temperate bacteriophage. 
C) only those temperate bacteriophages that integrate into the host chromosome. 
D) All of the choices are correct. 
A) any bacteriophage. 
B) any temperate bacteriophage. 
C) only those temperate bacteriophages that integrate into the host chromosome. 
D) All of the choices are correct.

Question 8

The conjugation bridge in an Hfr * F- mating usually breaks before chromosome transfer is complete; however,because at least part of the plasmid is transferred first,the recipient becomes F+.

Accepted Answer

A) True 
 B)False

Question 9

If chromosomal DNA from a host and phage DNA are carried by a transducing particle,what can be concluded regarding transduction in this case?

Accepted Answer

A) Transduction in this case is generalized rather than specialized. 
B) Transduction in this case is specialized rather than generalized. 
C) Transduction in this case could be generalized or specialized depending on the phage involved. 
D) Transduction in this case is neither generalized nor specialized. 
A) Transduction in this case is generalized rather than specialized. 
B) Transduction in this case is specialized rather than generalized. 
C) Transduction in this case could be generalized or specialized depending on the phage involved. 
D) Transduction in this case is neither generalized nor specialized.

Question 10

Which of the following is true of the integration of a viral genome into the host chromosome?

Accepted Answer

A) Integration of the viral genome is a form of site-specific recombination. 
B) The enzymes that are used in integration are nonspecific for the virus and its host. 
C) Integration begins the process of host chromosome degradation. 
D) All of the choices are correct. 
A) Integration of the viral genome is a form of site-specific recombination. 
B) The enzymes that are used in integration are nonspecific for the virus and its host. 
C) Integration begins the process of host chromosome degradation. 
D) All of the choices are correct.

Question 11

Who is credited with demonstrating unidirectional and nonreciprocal transfer of DNA between two mating

Accepted Answer

A) Hayes 
B) Lederberg 
C) Tatum 
D) None of the choices are correct. 
E) coli cells? 
A) Hayes 
B) Lederberg 
C) Tatum 
D) None of the choices are correct. 
E) coli cells?

Question 12

What type of procedure is appropriate to isolate revertants from a population of threonine auxotrophic cells?

Accepted Answer

A) Grow the auxotrophic cells on an agar plate without threonine; any colonies that form are presumed revertant. 
B) Grow the auxotrophic cells on and agar plate with threonine; any colonies that form are presumed revertant. 
C) Grow the auxotrophic cells in broth with threonine; if the broth becomes cloudy,revertants are presumed present. 
D) Threonine auxotrophic revertants could not be isolated on any type of media. 
A) Grow the auxotrophic cells on an agar plate without threonine; any colonies that form are presumed revertant. 
B) Grow the auxotrophic cells on and agar plate with threonine; any colonies that form are presumed revertant. 
C) Grow the auxotrophic cells in broth with threonine; if the broth becomes cloudy,revertants are presumed present. 
D) Threonine auxotrophic revertants could not be isolated on any type of media.

Question 13

When a recipient cell acquires a piece of naked DNA from the environment,it is called

Accepted Answer

A) conjugation. 
B) transformation. 
C) transduction. 
D) transfection. 
A) conjugation. 
B) transformation. 
C) transduction. 
D) transfection.

Question 14

An insertion sequence is distinguishable from other mobile genetic elements because

Accepted Answer

A) it is smallest. 
B) it encodes a transposase. 
C) it is highly complex. 
D) it is composed of DNA. 
A) it is smallest. 
B) it encodes a transposase. 
C) it is highly complex. 
D) it is composed of DNA.

Question 15

A transposable element composed of an antibiotic resistance gene,a recombinase gene,and inverted repeats is identified in a bacterial genome.This element can be any of the following except

Accepted Answer

A) an insertion sequence. 
B) a composite transposon. 
C) a unit transposon. 
D) an integrated conjugative element. 
A) an insertion sequence. 
B) a composite transposon. 
C) a unit transposon. 
D) an integrated conjugative element.

Question 16

__________ mutations occur in the promoter or operator region of a gene or set of genes and affects the expression of the downstream genes without affecting the amino acid sequences of the gene products.

Accepted Answer

The answer of __________ mutations occur in the promoter or...

Question 17

When an F plasmid integrates into the host chromosome,the strain is referred to as

Accepted Answer

A) F+. 
B) Hfr. 
C) F'. 
D) F-. 
A) F+. 
B) Hfr. 
C) F'. 
D) F-.

Question 18

Which of the following is considered a reverse mutation that will restore the wild type phenotype?

Accepted Answer

A) True reversion back to the wild type base sequence. 
B) Mutation to a different base sequence,but one that restores the amino acid sequence in the protein to the wild type sequence. 
C) A mutation that restores the function of a protein even though it does not restore the base sequence or the amino acid sequence to the wild type. 
D) All of the choices are correct. 
A) True reversion back to the wild type base sequence. 
B) Mutation to a different base sequence,but one that restores the amino acid sequence in the protein to the wild type sequence. 
C) A mutation that restores the function of a protein even though it does not restore the base sequence or the amino acid sequence to the wild type. 
D) All of the choices are correct.

Question 19

A recipient cell that is temporarily diploid for a portion of the genome during the replacement process is called a(n)__________.

Accepted Answer

A) merozygote 
B) exogenote 
C) endogenote 
D) None of the choices are correct. 
A) merozygote 
B) exogenote 
C) endogenote 
D) None of the choices are correct.

Question 20

Photoreactivation repairs thymine dimers by splitting them back into separate thymines.

Accepted Answer

A) True 
 B)False

Exam 16: Mechanisms of Genetic Variation

If the att site of Escherichia coli was dissimilar to that of lambda phage due to a mutation,how would transduction be affected?

Host __________ is the process by which some cells are capable of degrading an exogenote.

Predict the outcome of an F+ to F- mating if the F+ cell lacked a functional tra operon.

Mutations that result in the death of an organism when expressed are called __________ mutations.

Alternate forms of genes resulting from mutations are called

A microbial geneticist observes that a significant number of pyrimidine dimers are present in bacterial DNA following exposure to a particular mutagen.To which mutagen were the bacterial cells likely exposed?

Specialized transduction can be carried out by

The conjugation bridge in an Hfr * F- mating usually breaks before chromosome transfer is complete; however,because at least part of the plasmid is transferred first,the recipient becomes F+.

If chromosomal DNA from a host and phage DNA are carried by a transducing particle,what can be concluded regarding transduction in this case?

Which of the following is true of the integration of a viral genome into the host chromosome?

Who is credited with demonstrating unidirectional and nonreciprocal transfer of DNA between two mating

What type of procedure is appropriate to isolate revertants from a population of threonine auxotrophic cells?

When a recipient cell acquires a piece of naked DNA from the environment,it is called

An insertion sequence is distinguishable from other mobile genetic elements because

A transposable element composed of an antibiotic resistance gene,a recombinase gene,and inverted repeats is identified in a bacterial genome.This element can be any of the following except

__________ mutations occur in the promoter or operator region of a gene or set of genes and affects the expression of the downstream genes without affecting the amino acid sequences of the gene products.

When an F plasmid integrates into the host chromosome,the strain is referred to as

Which of the following is considered a reverse mutation that will restore the wild type phenotype?

A recipient cell that is temporarily diploid for a portion of the genome during the replacement process is called a(n)__________.

Photoreactivation repairs thymine dimers by splitting them back into separate thymines.

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

Predict the outcome of an F⁺to F^- mating if the F⁺ cell lacked a functional tra operon.

The conjugation bridge in an Hfr * F^- mating usually breaks before chromosome transfer is complete; however,because at least part of the plasmid is transferred first,the recipient becomes F⁺.