Question 1

The phenotype of an organism reflects only part of its genotype.

Accepted Answer

A) True 
 B)False  True

Question 2

Compare and contrast the lactose operon with the tryptophan operon.

Accepted Answer

Both the lactose and the tryptophan operons have certain features in common.They both contain a set of genes dedicated to a common purpose (such as the catabolism of lactose by the genes of the lactose operon)and regulatory elements such as a promoter and an operator.Each of these operons makes use of a repressor protein,which binds to the operator region and alters the activity of the operon.However,the lactose operon is classified as an inducible operon,which means it requires an inducer (a lactose metabolite)in order to be activated.In the absence of the inducer,the repressor protein shuts down the operon.In contrast,the tryptophan operon is a repressible operon,which requires a corepressor (tryptophan itself)in order to activate the repressor and shut down the operon.In the absence of the corepressor and repressor,the operon is fully functional.In both types of operons,the molecule either catabolized (in the case of lactose)or synthesized (in the case of tryptophan)is an important component of the regulation of the operon.In this way,the cell maintains precise control over these genetic pathways and does not spend time and energy making enzymes that are not needed.For example,making enzymes to catabolize lactose when no lactose is present would waste energy and metabolites.

Question 3

Typical eukaryotic genomes are composed of ________ chromosomes.

Accepted Answer

A)  multiple linear 
B)  multiple circular 
C)  a single circular 
D)  a single linear 
E)  both linear and circular 
A)  multiple linear 
B)  multiple circular 
C)  a single circular 
D)  a single linear 
E)  both linear and circular A

Question 4

A codon is a particular combination of three nucleotides.Therefore,there are ________ possible combinations of the nucleotides A,C,G,and T.

Accepted Answer

A)  16 
B)  4 
C)  12 
D)  64 
E)  32 
A)  16 
B)  4 
C)  12 
D)  64 
E)  32

Question 5

The chemical 5-bromouracil mimics the chemical structure of thymine,making it a(n)(analog/nucleotide/precursor)of thymine.

Accepted Answer

The answer of The chemical 5-bromouracil mimics the chemical structure...

Question 6

The effects of a transposition event are equivalent to a(n)

Accepted Answer

A)  nonsense mutation. 
B)  missense mutation. 
C)  frameshift mutation. 
D)  silent mutation. 
E)  HFR conjugation. 
A)  nonsense mutation. 
B)  missense mutation. 
C)  frameshift mutation. 
D)  silent mutation. 
E)  HFR conjugation.

Question 7

Which of the following is NOT a characteristic of Okazaki fragments?

Accepted Answer

A)  They are checked for accuracy by DNA polymerase III. 
B)  They make up the lagging strand of replicated DNA. 
C)  They begin with an RNA primer. 
D)  They are joined together by DNA ligase. 
E)  They are longer in eukaryotic cells. 
A)  They are checked for accuracy by DNA polymerase III. 
B)  They make up the lagging strand of replicated DNA. 
C)  They begin with an RNA primer. 
D)  They are joined together by DNA ligase. 
E)  They are longer in eukaryotic cells.

Question 8

In generalized transduction,viruses carry random DNA sequences from one cell to another.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following mechanisms normally repairs pyrimidine dimers?

Accepted Answer

A)  base-excision repair 
B)  light repair 
C)  single-strand repair 
D)  error-prone repair 
E)  SOS response repair 
A)  base-excision repair 
B)  light repair 
C)  single-strand repair 
D)  error-prone repair 
E)  SOS response repair

Question 10

The enzyme responsible for separating the DNA strands during DNA replication is (topoisomerase/primase/helicase).

Accepted Answer

The answer of The enzyme responsible for separating the DNA...

Question 11

Nucleotide analogs cause frameshift mutations.

Accepted Answer

A) True 
 B)False

Question 12

A(n)(operon/codon/gene)is a specific sequence of nucleotides that codes for a protein or an RNA molecule.

Accepted Answer

The answer of A(n)(operon/codon/gene)is a specific sequence of nucleotides that...

Question 13

The phenotype of an organism is its set of (genes/traits/chromosomes).

Accepted Answer

The answer of The phenotype of an organism is its...

Question 14

Bacterial strain A contains a plasmid.Bacterial strain B does not.When the bacteria are incubated together in a broth culture strain B cells containing the plasmid can be isolated.Devise an experiment to determine what type of gene transfer process is involved.

Accepted Answer

A variety of answers are possible.For ex

Question 15

The horizontal transfer process known as transduction

Accepted Answer

A)  involves a virus. 
B)  requires a pilus. 
C)  requires a cell to be "competent." 
D)  requires a plasmid. 
E)  involves a mutagen. 
A)  involves a virus. 
B)  requires a pilus. 
C)  requires a cell to be "competent." 
D)  requires a plasmid. 
E)  involves a mutagen.

Question 16

The (leading/lagging/replicating)strand is the DNA strand that is synthesized continuously during DNA replication.

Accepted Answer

The answer of The (leading/lagging/replicating)strand is the DNA strand that...

Question 17

Which of the following causes mutations by creating thymine dimers?

Accepted Answer

A)  nucleotide analogs 
B)  nitrous acid 
C)  ultraviolet light 
D)  benzopyrene 
E)  gamma rays 
A)  nucleotide analogs 
B)  nitrous acid 
C)  ultraviolet light 
D)  benzopyrene 
E)  gamma rays

Question 18

Genetic elements known as promoters are initiation points in the process of

Accepted Answer

A)  DNA replication. 
B)  transcription. 
C)  translation. 
D)  mutation repair. 
E)  transformation. 
A)  DNA replication. 
B)  transcription. 
C)  translation. 
D)  mutation repair. 
E)  transformation.

Question 19

Which of the following is a characteristic shared by DNA and RNA polymerases?

Accepted Answer

A)  efficiency of proofreading 
B)  type of nucleotides used 
C)  direction of polymerization 
D)  speed 
E)  dependence on helicase 
A)  efficiency of proofreading 
B)  type of nucleotides used 
C)  direction of polymerization 
D)  speed 
E)  dependence on helicase

Question 20

A point mutation can be completely harmless,or it can result in the death of a cell or organism.Explain why these types of mutations can have such varying effects.

Accepted Answer

A point mutation is a single base change

Exam 7: Microbial Genetics

The phenotype of an organism reflects only part of its genotype.

Compare and contrast the lactose operon with the tryptophan operon.

Typical eukaryotic genomes are composed of ________ chromosomes.

A codon is a particular combination of three nucleotides.Therefore,there are ________ possible combinations of the nucleotides A,C,G,and T.

The chemical 5-bromouracil mimics the chemical structure of thymine,making it a(n)(analog/nucleotide/precursor)of thymine.

The effects of a transposition event are equivalent to a(n)

Which of the following is NOT a characteristic of Okazaki fragments?

In generalized transduction,viruses carry random DNA sequences from one cell to another.

Which of the following mechanisms normally repairs pyrimidine dimers?

The enzyme responsible for separating the DNA strands during DNA replication is (topoisomerase/primase/helicase).

Nucleotide analogs cause frameshift mutations.

A(n)(operon/codon/gene)is a specific sequence of nucleotides that codes for a protein or an RNA molecule.

The phenotype of an organism is its set of (genes/traits/chromosomes).

Bacterial strain A contains a plasmid.Bacterial strain B does not.When the bacteria are incubated together in a broth culture strain B cells containing the plasmid can be isolated.Devise an experiment to determine what type of gene transfer process is involved.

The horizontal transfer process known as transduction

The (leading/lagging/replicating)strand is the DNA strand that is synthesized continuously during DNA replication.

Which of the following causes mutations by creating thymine dimers?

Genetic elements known as promoters are initiation points in the process of

Which of the following is a characteristic shared by DNA and RNA polymerases?

A point mutation can be completely harmless,or it can result in the death of a cell or organism.Explain why these types of mutations can have such varying effects.

A Brief History of Microbiology

The Chemistry of Microbiology

Cell Structure and Function

Microscopy, Staining, and Classification

Microbial Metabolism

Microbial Nutrition and Growth

Recombinant DNA Technology

Controlling Microbial Growth in the Environment

Controlling Microbial Growth in the Body: Antimicrobial Drugs

Characterizing and Classifying Prokaryotes

Characterizing and Classifying Eukaryotes

Characterizing and Classifying Viruses, Viroids, and Prions

Infection, Infectious Diseases, and Epidemiology

Innate Immunity

Adaptive Immunity

Immunization and Immune Testing

Immune Disorders

Pathogenic Gram Positive Bacteria

Pathogenic Gram-Negative Cocci and Bacilli

Rickettsias, Chlamydias, Spirochetes, and Vibrios

Pathogenic Fungi

Parasitic Protozoa, Helminths, and Arthropod Vectors

Pathogenic DNA Viruses

Pathogenic RNA Viruses

Applied and Environmental Microbiology

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