Question 1

Why does conjugation with an Hfr donor result in a much higher rate of gene transfer than conjugation with an F+ donor?

Accepted Answer

A)  An F+ donor makes fewer pili. 
B)  The Hfr donor segment must undergo recombination in the recipient. 
C)  An F+ donor's T strand is slow to reach the pilus. 
D)  The Hfr donor transfers genes from the chromosome and not the plasmid. 
E)  The F+ donor segment must undergo recombination in the recipient. 
A)  An F+ donor makes fewer pili. 
B)  The Hfr donor segment must undergo recombination in the recipient. 
C)  An F+ donor's T strand is slow to reach the pilus. 
D)  The Hfr donor transfers genes from the chromosome and not the plasmid. 
E)  The F+ donor segment must undergo recombination in the recipient. D

Question 2

Benzer's analysis of phage genomes included deletion mapping. Since recombination could not occur in the area of a deletion, an infection by two phage strains, one of which has a deletion and the other a point mutation, that results in no wild- type recombinants being produced indicates_________ .

Accepted Answer

A)  that the deletion includes the position of the point mutation in a different gene 
B)  the distance between the two types of mutation 
C)  that the point mutation is recessive 
D)  that the deletion includes the position of the point mutation in the same gene 
E)  that the point mutation is dominant 
A)  that the deletion includes the position of the point mutation in a different gene 
B)  the distance between the two types of mutation 
C)  that the point mutation is recessive 
D)  that the deletion includes the position of the point mutation in the same gene 
E)  that the point mutation is dominant D

Question 3

A scientist is studying a gene (grn) carried by a bacteriophage that allows a host bacterium to produce a green metabolic product before lysis. The scientist has four bacteriophage mutants for this gene. Mutant 1 has a nonrevertible mutation in grn while Mutants 2, 3, and 4 each have a revertible mutation in grn. After plating pairs of mutants and subsequent coinfection of host cells, the scientist observed the following: I. Mutants 1 and 2: no green product
II) Mutants 1 and 3: very rare green product
III) Mutants 1 and 4: rare green product
Which of the following is NOT consistent with these observations?

Accepted Answer

A)  Mutant 2 has a base- pair substitution at a different site than Mutant 3. 
B)  A green product should be observed if coinfection occurs with mutants 3 and 4. 
C)  Mutant 1's deletion is closer to the base- pair substitution in Mutant 3 than it is to the base- pair substitution in Mutant 4. 
D)  A partial deletion in Mutant 1 overlaps a base- pair substitution in Mutant 2. 
E)  Mutant 3 has a base- pair substitution at a different site than Mutant 4. 
A)  Mutant 2 has a base- pair substitution at a different site than Mutant 3. 
B)  A green product should be observed if coinfection occurs with mutants 3 and 4. 
C)  Mutant 1's deletion is closer to the base- pair substitution in Mutant 3 than it is to the base- pair substitution in Mutant 4. 
D)  A partial deletion in Mutant 1 overlaps a base- pair substitution in Mutant 2. 
E)  Mutant 3 has a base- pair substitution at a different site than Mutant 4. C

Question 4

Jacob and colleagues developed a time- of- entry mapping technique. They used the genes for threonine and leucine synthesis (thr and leu), which are near the oriT site, as selected markers. Additionally, they used an E. coli F- strain P678 that has dysfunctional variants for all of the genes studied. They also used an HfrH strain that carried a functional allele for all genes studied. Which of the following statements is FALSE regarding the time- of- entry profile they acquired?

Accepted Answer

A)  The azi gene is closer to the thr and leu genes than the ton, lac, and gal genes. 
B)  The ton gene is found between the azi and lac genes. 
C)  Had the experiment continued, a time of entry map could be viewed for the entire E. coli chromosome. 
D)  The lac+ allele appears at about 16 or 17 minutes. 
E)  At 40 minutes, nearly 20% of exconjugants screened for the selected markers have the gal allele. 
A)  The azi gene is closer to the thr and leu genes than the ton, lac, and gal genes. 
B)  The ton gene is found between the azi and lac genes. 
C)  Had the experiment continued, a time of entry map could be viewed for the entire E. coli chromosome. 
D)  The lac+ allele appears at about 16 or 17 minutes. 
E)  At 40 minutes, nearly 20% of exconjugants screened for the selected markers have the gal allele.

Question 5

What is the difference between the revertible and nonrevertible rII mutants that Benzer generated?

Accepted Answer

revertible mutants were caused

Question 6

Which of the following regarding lateral gene transfer is false?

Accepted Answer

A)  It can convert benign bacteria into pathogens that cause disease. 
B)  It facilitates rapid genome evolution. 
C)  It may occur by conjugation, transformation, or transduction. 
D)  It increases the efficiency of antibiotics against normally sensitive strains. 
E)  It allows an organism to rapidly acquire whole segments of chromosomes containing multiple genes. 
A)  It can convert benign bacteria into pathogens that cause disease. 
B)  It facilitates rapid genome evolution. 
C)  It may occur by conjugation, transformation, or transduction. 
D)  It increases the efficiency of antibiotics against normally sensitive strains. 
E)  It allows an organism to rapidly acquire whole segments of chromosomes containing multiple genes.

Question 7

What distinguishes generalized versus specialized transduction?

Accepted Answer

generalized uses lyt

Question 8

A lab technician has four strains of bacteria. Although he forgot to label them, he knows that they include one F+ strain, one Hfr strain, one F' strain, and one F- strain. He observed the following results after plating these strains on different media. Which of the following plates can be used to identify the F- strain? $$\begin{array} { | l l l l l l | } 
\hline \text { strain } & \text { his } & g \text { gu } & \text { cys } & \text { leu } & \text { str } \
\mathrm { F } ^ { + } & + & + & + & - & + \
\mathrm { Hfr } & + & + & + & + & - \
\mathrm { F } ^ { \prime } & + & + & + & + & - \
\mathrm { F } & - & - & - & + & + \
\hline
\end{array}$$

Accepted Answer

A)  minimal media with leucine and streptomycin 
B)  minimal media with histidine, glutamate, and cysteine 
C)  minimal media with histidine, glutamate, cysteine, and streptomycin 
D)  complete media 
E)  minimal media with streptomycin 
A)  minimal media with leucine and streptomycin 
B)  minimal media with histidine, glutamate, and cysteine 
C)  minimal media with histidine, glutamate, cysteine, and streptomycin 
D)  complete media 
E)  minimal media with streptomycin

Question 9

To map genes of a bacterial strain, conjugation must be interrupted at given times. Suppose you have Hfr cells of genotype a+b+c+d+e+strR and F- cells of genotype a- b- c- d- e- strS and you combine these two cultures in liquid medium in four blenders at time 0. After intervals of 3, 6, 9, and 12 minutes, you turn on successive blenders. The graph below shows the results of plating the cultures from each blender. What is the correct order of the genes on this chromosome?

Accepted Answer

A)  a b c d e 
B)  b e c a d 
C)  a c e b d 
D)  d a c e b 
E)  b e c a (d is unknown) 
A)  a b c d e 
B)  b e c a d 
C)  a c e b d 
D)  d a c e b 
E)  b e c a (d is unknown)

Question 10

If conjugation occurs with an F' donor, how will the recipient be characterized genetically?

Accepted Answer

The answer of If conjugation occurs with an F' donor,...

Question 11

Which of the following statements regarding cotransduction mapping experiments is false?

Accepted Answer

A)  An unselected marker screen identifies transductants for an additional donor allele of interest. 
B)  Selection identifies transductants that have acquired an even number of crossovers. 
C)  A selected marker screen identifies transductants for a donor allele of interest. 
D)  A low co- transduction frequency between two genes is evidence of linkage. 
E)  A high co- transduction frequency between two genes is evidence of linkage. 
A)  An unselected marker screen identifies transductants for an additional donor allele of interest. 
B)  Selection identifies transductants that have acquired an even number of crossovers. 
C)  A selected marker screen identifies transductants for a donor allele of interest. 
D)  A low co- transduction frequency between two genes is evidence of linkage. 
E)  A high co- transduction frequency between two genes is evidence of linkage.

Question 12

A competent bacterial strain with genes a, b, and c is transformed by a donor bacterial fragment. Cotransformation frequencies for each gene pair are as follows: $a$ and $b \quad 0.04 \%$
$a$ and $c \quad 0.02 \%$
$b$ and $c \quad 0.0064 \%$ Which conclusion can be definitively made from this data?

Accepted Answer

A)  Cotransformation of b and c is so frequent, they must be one gene. 
B)  Gene b is closer to c than to a. 
C)  Gene a is closer to c than to b. 
D)  Gene order is a, b, then c. 
E)  Genes b and c are farthest apart. 
A)  Cotransformation of b and c is so frequent, they must be one gene. 
B)  Gene b is closer to c than to a. 
C)  Gene a is closer to c than to b. 
D)  Gene order is a, b, then c. 
E)  Genes b and c are farthest apart.

Question 13

Bacteria that can grow on minimal medium are called
   require one or more essential compounds for growth are called

Accepted Answer

prototrophs; auxotro

Question 14

In generalized transduction, a phage introduces a segment of donor DNA into the recipient cell. This is followed by recombination of the donor fragment with the recipient chromosome. Which of the following must occur?

Accepted Answer

A)  degradation of one of the two strands of phage genome 
B)  circularization of the donor fragment before recombination 
C)  a single crossover between the donor segment and the recipient chromosome 
D)  a pair (or even number) of crossovers between the donor segment and the recipient 
E)  replication of the donor segment before recombination 
A)  degradation of one of the two strands of phage genome 
B)  circularization of the donor fragment before recombination 
C)  a single crossover between the donor segment and the recipient chromosome 
D)  a pair (or even number) of crossovers between the donor segment and the recipient 
E)  replication of the donor segment before recombination

Question 15

Which of the following is NOT a step involved in rolling circle replication during conjugation?

Accepted Answer

A)  A protein complex known as the relaxosome cuts one strand of the F+ plasmid. 
B)  A double stranded plasmid is transferred to the F- cell through the conjugation pilus. 
C)  Rolling circle replication occurs in the donor. 
D)  Replication begins at the oriT after relaxosome binding. 
E)  Relaxase facilitates passage of the T strand into the recipient cell. 
A)  A protein complex known as the relaxosome cuts one strand of the F+ plasmid. 
B)  A double stranded plasmid is transferred to the F- cell through the conjugation pilus. 
C)  Rolling circle replication occurs in the donor. 
D)  Replication begins at the oriT after relaxosome binding. 
E)  Relaxase facilitates passage of the T strand into the recipient cell.

Question 16

Which of the following is incorrect about genetic analysis and mapping in bacteria and bacteriophages?

Accepted Answer

A)  Generalized transduction uses lytic phage and specialized transduction uses a lysogenic phage. 
B)  Conjugation, transformation, and transduction all require recombination. 
C)  Conjugation requires cell- to- cell contact. 
D)  Conjugation, transformation, and transduction can all be used to map the order of genes on a bacterial chromosome. 
E)  Transformation requires a vector to carry donor DNA fragments to the recipient cell. 
A)  Generalized transduction uses lytic phage and specialized transduction uses a lysogenic phage. 
B)  Conjugation, transformation, and transduction all require recombination. 
C)  Conjugation requires cell- to- cell contact. 
D)  Conjugation, transformation, and transduction can all be used to map the order of genes on a bacterial chromosome. 
E)  Transformation requires a vector to carry donor DNA fragments to the recipient cell.

Question 17

Some bacteriophages can be either lytic or lysogenic. These are called _ phages.

Accepted Answer

The answer of Some bacteriophages can be either lytic or...

Question 18

Which of the following is false regarding plasmids?

Accepted Answer

A)  They can have genes that promote their own transfer from one bacterium to another. 
B)  They contain essential genes for metabolism. 
C)  They can carry genes for antibiotic resistance. 
D)  They generally replicate autonomously. 
E)  They are small double stranded circular DNA molecules. 
A)  They can have genes that promote their own transfer from one bacterium to another. 
B)  They contain essential genes for metabolism. 
C)  They can carry genes for antibiotic resistance. 
D)  They generally replicate autonomously. 
E)  They are small double stranded circular DNA molecules.

Question 19

Which of the following statements about the T4 lytic life cycle is false?

Accepted Answer

A)  Under the direction of phage genes, transcription and translation produce new phage components. 
B)  The phage DNA is injected into the host. 
C)  Progeny phage particles are released by lysis from host bacteria. 
D)  The phage DNA is integrated into the host chromosome. 
E)  The host DNA breaks down. 
A)  Under the direction of phage genes, transcription and translation produce new phage components. 
B)  The phage DNA is injected into the host. 
C)  Progeny phage particles are released by lysis from host bacteria. 
D)  The phage DNA is integrated into the host chromosome. 
E)  The host DNA breaks down.

Question 20

To map genes of a bacterial strain, conjugation must be interrupted at given times. Suppose you have Hfr cells of genotype a+b+c+d+e+strR and F- cells of genotype a- b- c- d- e- strS and you combine these two cultures in liquid medium in four blenders at time 0. After intervals of 3, 6, 9, and 12 minutes, you turn on successive blenders. The resulting cultures were then plated on medium containing streptomycin. Why?

Accepted Answer

A)  to eliminate non- conjugating Hfr cells 
B)  to selectively eliminate cells that have taken in F+ genes 
C)  to eliminate non- conjugated F- cells 
D)  to eliminate all non- conjugated cells 
A)  to eliminate non- conjugating Hfr cells 
B)  to selectively eliminate cells that have taken in F+ genes 
C)  to eliminate non- conjugated F- cells 
D)  to eliminate all non- conjugated cells

Why does conjugation with an Hfr donor result in a much higher rate of gene transfer than conjugation with an F+ donor?

Benzer's analysis of phage genomes included deletion mapping. Since recombination could not occur in the area of a deletion, an infection by two phage strains, one of which has a deletion and the other a point mutation, that results in no wild- type recombinants being produced indicates_________ .

What is the difference between the revertible and nonrevertible rII mutants that Benzer generated?

Which of the following regarding lateral gene transfer is false?

What distinguishes generalized versus specialized transduction?

If conjugation occurs with an F' donor, how will the recipient be characterized genetically?

Which of the following statements regarding cotransduction mapping experiments is false?

A competent bacterial strain with genes a, b, and c is transformed by a donor bacterial fragment. Cotransformation frequencies for each gene pair are as follows: $a$ and $b \quad 0.04 \%$ $a$ and $c \quad 0.02 \%$ $b$ and $c \quad 0.0064 \%$ Which conclusion can be definitively made from this data?

Bacteria that can grow on minimal medium are called require one or more essential compounds for growth are called

In generalized transduction, a phage introduces a segment of donor DNA into the recipient cell. This is followed by recombination of the donor fragment with the recipient chromosome. Which of the following must occur?

Which of the following is NOT a step involved in rolling circle replication during conjugation?

Which of the following is incorrect about genetic analysis and mapping in bacteria and bacteriophages?

Some bacteriophages can be either lytic or lysogenic. These are called _ phages.

Which of the following is false regarding plasmids?

Which of the following statements about the T4 lytic life cycle is false?

The Molecular Basis of Heredity, Variation, and Evolution

Transmission Genetics

Cell Division and Chromosome Heredity

Inheritance Patterns of Single Genes and Gene Interaction

Genetic Linkage and Mapping in Eukaryotes

Dna Structure and Replication

Molecular Biology of Transcription and Rna Processing

The Molecular Biology of Translation

Chromosome Chapter Title Tbd

Gene Mutation, Dna Repair, and Homologous Recombination

Chromosome Chapter Title Tbd

Regulation of Gene Expression in Bacteria and Bacteriophage

Regulation of Gene Expression in Eukaryotes

Analysis of Gene Function by Forward Genetics and Reverse Genetics

Recombinant Dna Technology and Its Applications

Genomics: Genetics From a Whole-Genome Perspective

Organelle Inheritance and the Evolution of Organelle Genomes

Developmental Genetics

Genetic Analysis of Quantitative Traits

Population Genetics and Evolution at the Population, Species, and Molecular Levels

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Exam 6: Genetic Analysis and Mapping in Bacteria and Bacteriophage

Why does conjugation with an Hfr donor result in a much higher rate of gene transfer than conjugation with an F+ donor?

Benzer's analysis of phage genomes included deletion mapping. Since recombination could not occur in the area of a deletion, an infection by two phage strains, one of which has a deletion and the other a point mutation, that results in no wild- type recombinants being produced indicates_________ .

What is the difference between the revertible and nonrevertible rII mutants that Benzer generated?

Which of the following regarding lateral gene transfer is false?

What distinguishes generalized versus specialized transduction?

If conjugation occurs with an F' donor, how will the recipient be characterized genetically?

Which of the following statements regarding cotransduction mapping experiments is false?

Bacteria that can grow on minimal medium are called require one or more essential compounds for growth are called

In generalized transduction, a phage introduces a segment of donor DNA into the recipient cell. This is followed by recombination of the donor fragment with the recipient chromosome. Which of the following must occur?

Which of the following is NOT a step involved in rolling circle replication during conjugation?

Which of the following is incorrect about genetic analysis and mapping in bacteria and bacteriophages?

Some bacteriophages can be either lytic or lysogenic. These are called _ phages.

Which of the following is false regarding plasmids?

Which of the following statements about the T4 lytic life cycle is false?

The Molecular Basis of Heredity, Variation, and Evolution

Transmission Genetics

Cell Division and Chromosome Heredity

Inheritance Patterns of Single Genes and Gene Interaction

Genetic Linkage and Mapping in Eukaryotes

Dna Structure and Replication

Molecular Biology of Transcription and Rna Processing

The Molecular Biology of Translation

Chromosome Chapter Title Tbd

Gene Mutation, Dna Repair, and Homologous Recombination

Chromosome Chapter Title Tbd

Regulation of Gene Expression in Bacteria and Bacteriophage

Regulation of Gene Expression in Eukaryotes

Analysis of Gene Function by Forward Genetics and Reverse Genetics

Recombinant Dna Technology and Its Applications

Genomics: Genetics From a Whole-Genome Perspective

Organelle Inheritance and the Evolution of Organelle Genomes

Developmental Genetics

Genetic Analysis of Quantitative Traits

Population Genetics and Evolution at the Population, Species, and Molecular Levels

Filters