Question 1

A change in genotype,but not in phenotype,is most likely due to

Accepted Answer

A) a nonsense mutation at the beginning of a gene. 
B) a point mutation in the third position of a DNA triplet. 
C) a mutation that leads to a frameshift in the middle of a gene. 
D) thymine dimer formation in the coding region of a gene. 
A) a nonsense mutation at the beginning of a gene. 
B) a point mutation in the third position of a DNA triplet. 
C) a mutation that leads to a frameshift in the middle of a gene. 
D) thymine dimer formation in the coding region of a gene.

Question 2

The incorporation of a single strand of donor DNA into a recipient DNA duplex so that the donor strand replaces one of the strands or the recipient duplex generates __________ DNA.

Accepted Answer

A) aberrant 
B) unstable 
C) heterogeneous 
D) heteroduplex 
A) aberrant 
B) unstable 
C) heterogeneous 
D) heteroduplex

Question 3

_______ are strains that are unable to grow on a minimal medium that supports growth of the wild type strain,but are able to grow on the minimal medium if one or more nutritional supplements are added.

Accepted Answer

A) Autotrophs 
B) Auxotrophs 
C) Prototrophs 
D) Minitrophs 
A) Autotrophs 
B) Auxotrophs 
C) Prototrophs 
D) Minitrophs

Question 4

Which of the following types of mutation may play an important role in driving evolution because they are often nonlethal and,therefore,remain in the gene pool?

Accepted Answer

A) Nonsense 
B) Missense 
C) Frameshift 
D) Deletion 
A) Nonsense 
B) Missense 
C) Frameshift 
D) Deletion

Question 5

If 5-bromouracil was added to a culture of actively dividing bacterial cells,resulting mutations could eventually become a stable part of the cellular genome.

Accepted Answer

A) True 
 B)False

Question 6

A public health microbiologist plans to screen a particular bacterial species that was isolated from several patients in an intensive care unit to detect if any of the cells are penicillin-resistant mutants.What is the first step in conducting this experiment?

Accepted Answer

A) Determine whether or not wild type cells of the same bacterial species are susceptible to penicillin. 
B) Test the cells to see if they can grow on media to which penicillin has been added. 
C) Perform an antibiotic susceptibility test on the cells using antibiotics other than penicillin that are known to be effective. 
D) Set up an Ames test to see if any of the isolates are mutagenic. 
A) Determine whether or not wild type cells of the same bacterial species are susceptible to penicillin. 
B) Test the cells to see if they can grow on media to which penicillin has been added. 
C) Perform an antibiotic susceptibility test on the cells using antibiotics other than penicillin that are known to be effective. 
D) Set up an Ames test to see if any of the isolates are mutagenic.

Question 7

__________ mutations affect only a single base pair in a gene.

Accepted Answer

The answer of __________ mutations affect only a single base...

Question 8

A mutation from the most prevalent form of a gene to a mutant form is called a __________ mutation.

Accepted Answer

A) forward 
B) reverse 
C) wild card 
D) escalating 
A) forward 
B) reverse 
C) wild card 
D) escalating

Question 9

A reciprocal exchange in which a pair of DNA with the same nucleotide sequence break and rejoin in a crossover is called __________ recombination.

Accepted Answer

A) homologous 
B) site-specific 
C) replicative 
D) None of the choices are correct. 
A) homologous 
B) site-specific 
C) replicative 
D) None of the choices are correct.

Question 10

Predict the outcome of protein synthesis if a gene undergoes a mutation in its anticodon region where a charged tRNA recognizes a nonsense mutation

Accepted Answer

A) Transcription and translation both would continue. 
B) Transcription would continue but translation would not continue. 
C) Transcription and translation both would not continue. 
D) Transcription would continue but translation would not continue 
A) Transcription and translation both would continue. 
B) Transcription would continue but translation would not continue. 
C) Transcription and translation both would not continue. 
D) Transcription would continue but translation would not continue

Question 11

Lethal mutations can be maintained in diploid organisms if they are

Accepted Answer

A) dominant. 
B) recessive. 
C) deletions. 
D) None of the choices are correct. 
A) dominant. 
B) recessive. 
C) deletions. 
D) None of the choices are correct.

Question 12

__________ are physical or chemical agents that cause mutation.

Accepted Answer

The answer of __________ are physical or chemical agents that...

Question 13

Which of the following is not a strategy that bacteria use to resist the action of antibiotics?

Accepted Answer

A) Modification of the antibiotic by the acetylation or phosphorylation. 
B) Cleavage of a key structural component of the antibiotic. 
C) Altering cell membrane structure to prevent antibiotic influx. 
D) All of the choices are correct. 
A) Modification of the antibiotic by the acetylation or phosphorylation. 
B) Cleavage of a key structural component of the antibiotic. 
C) Altering cell membrane structure to prevent antibiotic influx. 
D) All of the choices are correct.

Question 14

As the result of exposure to a mutagen,cytosine is substituted for thymine in one strand of DNA.Upon subsequent DNA replication,one of the daughter cells will have a GC pair in this position instead of an AT pair.This is called a(n)__________ mutation.

Accepted Answer

A) transversion 
B) transition 
C) frameshift 
D) insertion 
A) transversion 
B) transition 
C) frameshift 
D) insertion

Question 15

Transfer of genes from one mature independent organism to another is called

Accepted Answer

A) horizontal gene transfer. 
B) lateral gene transfer. 
C) vertical gene transfer. 
D) orthogonal gene transfer. 
A) horizontal gene transfer. 
B) lateral gene transfer. 
C) vertical gene transfer. 
D) orthogonal gene transfer.

Question 16

Plasmids that have genes that decrease bacterial susceptibility to antibiotics are called __________ factors.

Accepted Answer

A) col 
B) resistance 
C) virulence 
D) metabolic 
A) col 
B) resistance 
C) virulence 
D) metabolic

Question 17

Transposable elements have been found only in prokaryotes and do not appear to play a major role in eukaryotes.

Accepted Answer

A) True 
 B)False

Question 18

In an HFR * F+ mating,the conjugation bridge usually breaks before chromosomal transfer is complete.Therefore,the recipient remains F-.

Accepted Answer

A) True 
 B)False

Question 19

The transformation frequency of very competent cells is about 10-6,or about 1 in 1,000,000 when an excess of DNA is used.

Accepted Answer

A) True 
 B)False

Question 20

In an F+ * F- conjugation,the donor is the __________ strain.

Accepted Answer

A) F+ 
B) F- 
C) both F+ and F- (It is a reciprocal exchange) 
D) neither F+ nor F- (There is no exchange) 
A) F+ 
B) F- 
C) both F+ and F- (It is a reciprocal exchange) 
D) neither F+ nor F- (There is no exchange)

Exam 16: Mechanisms of Genetic Variation

A change in genotype,but not in phenotype,is most likely due to

The incorporation of a single strand of donor DNA into a recipient DNA duplex so that the donor strand replaces one of the strands or the recipient duplex generates __________ DNA.

_______ are strains that are unable to grow on a minimal medium that supports growth of the wild type strain,but are able to grow on the minimal medium if one or more nutritional supplements are added.

Which of the following types of mutation may play an important role in driving evolution because they are often nonlethal and,therefore,remain in the gene pool?

If 5-bromouracil was added to a culture of actively dividing bacterial cells,resulting mutations could eventually become a stable part of the cellular genome.

A public health microbiologist plans to screen a particular bacterial species that was isolated from several patients in an intensive care unit to detect if any of the cells are penicillin-resistant mutants.What is the first step in conducting this experiment?

__________ mutations affect only a single base pair in a gene.

A mutation from the most prevalent form of a gene to a mutant form is called a __________ mutation.

A reciprocal exchange in which a pair of DNA with the same nucleotide sequence break and rejoin in a crossover is called __________ recombination.

Predict the outcome of protein synthesis if a gene undergoes a mutation in its anticodon region where a charged tRNA recognizes a nonsense mutation

Lethal mutations can be maintained in diploid organisms if they are

__________ are physical or chemical agents that cause mutation.

Which of the following is not a strategy that bacteria use to resist the action of antibiotics?

As the result of exposure to a mutagen,cytosine is substituted for thymine in one strand of DNA.Upon subsequent DNA replication,one of the daughter cells will have a GC pair in this position instead of an AT pair.This is called a(n)__________ mutation.

Transfer of genes from one mature independent organism to another is called

Plasmids that have genes that decrease bacterial susceptibility to antibiotics are called __________ factors.

Transposable elements have been found only in prokaryotes and do not appear to play a major role in eukaryotes.

In an HFR * F+ mating,the conjugation bridge usually breaks before chromosomal transfer is complete.Therefore,the recipient remains F-.

The transformation frequency of very competent cells is about 10-6,or about 1 in 1,000,000 when an excess of DNA is used.

In an F+ * F- conjugation,the donor is the __________ strain.

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 HFR * F⁺ mating,the conjugation bridge usually breaks before chromosomal transfer is complete.Therefore,the recipient remains F^-.

The transformation frequency of very competent cells is about 10^-6,or about 1 in 1,000,000 when an excess of DNA is used.

In an F⁺ * F^- conjugation,the donor is the __________ strain.