p.9
Phage Genetics and Molecular Biology
Why are phage mutants easy to isolate?
Because of their distinct plaque morphology.
p.7
Phage Genetics and Molecular Biology
What would biology lack without the studies of phages?
It would not be where it is today.
p.4
Transduction Mechanisms and Terminology
What is transduction in genetics?
Transduction is the process by which DNA is transferred from one bacterium to another by a virus (phage).
p.19
Transduction Mechanisms and Terminology
What is transduction?
The use of phages to carry DNA from a donor to a recipient.
p.27
Genetic Analysis of Conjugation
What does argH + indicate?
Presence of the argH gene.
p.21
Transduction Mechanisms and Terminology
What is meant by 'large burst size' in the context of transducing phages?
It refers to high phage yield.
p.11
Phage Genetics and Molecular Biology
Which phage is referred to as P22?
A type of tailed bacteriophage.
p.33
Bacterial Transformation and Competence
What does it mean for bacteria to be competent?
The ability of bacteria to take up free DNA.
p.3
Selection Methods for F' Factors
What is the purpose of replica plating?
To identify and isolate specific mutants or phenotypes.
p.30
Hfr Mapping Techniques
What is the purpose of mapping rif r (rif - 8) mutations?
To determine the genetic vicinity of argH and metA.
p.15
Phage Genetics and Molecular Biology
What determines the host range of a phage?
The specific interaction between a phage protein and a receptor on the bacterial cell surface.
p.35
Mapping Bacterial Genes via Transduction
What is the most useful condition for mapping by transformation?
When a bacterium is naturally competent.
p.30
Hfr Mapping Techniques
What does Hfr stand for in genetic mapping?
Hfr stands for 'high frequency of recombination'.
p.22
Transduction Mechanisms and Terminology
Can a mutant form of T4 be a transducing phage?
Yes, a T4 mutant can be transducing.
p.4
Phage Genetics and Molecular Biology
How do phages contribute to genetic mapping?
Phages can be used as tools to introduce specific genes into bacterial cells, aiding in the mapping of bacterial genomes.
p.19
Transduction Mechanisms and Terminology
What is a transducing particle?
A phage that packages host (donor) DNA in a phage particle.
p.37
Genetic Analysis of Conjugation
What are the three main genetic transfer methods mentioned?
Conjugation, transformation, and transduction.
p.9
Phage Genetics and Molecular Biology
What characteristic of phage mutants makes them easy to study?
Their plaque morphology is easy to score.
p.7
Phage Genetics and Molecular Biology
What fundamental biological process do phages help study?
The DNA replication process.
p.20
Transduction Mechanisms and Terminology
What is a donor in transduction terminology?
A bacterial strain used to grow/propagate the transducing phage.
p.17
DNA Packaging in Phages
How much DNA can a phage head hold?
Up to 103% of its chromosome.
p.26
Genetic Analysis of Conjugation
What is the relationship of rif - 8 to argH and metA?
Rif - 8 is a recipient with argH - and metA +.
p.17
DNA Packaging in Phages
What happens to the DNA after it is packed into the phage head?
The DNA is cut, and the motor leaves with the remaining DNA to find another head.
p.25
Transduction Mechanisms and Terminology
What is a transductant?
The progeny or recombinant from the cross/transduction.
p.21
Transduction Mechanisms and Terminology
What does 'high titer' indicate about a transducing phage?
It indicates high phage concentration.
p.2
Genetic Analysis of Conjugation
What is the purpose of mutagenizing an F' lac strain?
To identify Tra - mutants.
p.36
Genetic Analysis of Conjugation
What is the result of crossing argH + metA - rif S and argH - metA + rif R?
The construction of arg + rif R strain or metA - rif R strain.
p.12
Phage Genetics and Molecular Biology
What types of genetic materials can phages have?
All kinds of genetic materials.
p.37
Genetic Analysis of Conjugation
What are conjugation, transformation, and transduction used for besides mapping?
They are used extensively for strain construction and other purposes.
p.22
Transduction Mechanisms and Terminology
What is a characteristic of the T4 phage?
It degrades host DNA upon infection.
p.35
Mapping Bacterial Genes via Transduction
How is the idea of co-transformation frequency similar?
It is similar to co-transduction frequency.
p.25
Transduction Mechanisms and Terminology
What is a recipient in the context of transduction?
A bacterial strain 'infected' by the transducing phage.
p.36
Genetic Analysis of Conjugation
What is the parental strain used for strain construction?
argH + metA - rif S and argH - metA + rif R.
p.25
Transduction Mechanisms and Terminology
What does 'a cross' refer to in transduction?
The process of transduction, mixing the genetic material of a recipient with that of a donor through a phage.
p.36
Genetic Analysis of Conjugation
What strains are being constructed from the parental strains?
An arg + rif R strain or a metA - rif R strain.
p.24
Hfr Mapping Techniques
Which mutations are being mapped in the context of Hfr?
The rif r (rif - 8) mutation.
p.15
Phage Genetics and Molecular Biology
What receptor does the T4 phage tail fiber interact with on the bacterial cell surface?
LPS (lipopolysaccharides).
p.4
Mapping Bacterial Genes via Transduction
What is the significance of mapping bacterial genes?
Mapping bacterial genes helps in understanding gene function, regulation, and interactions within the genome.
p.5
Phage Genetics and Molecular Biology
What indicates the presence of bacteriophages in a bacterial lawn?
Holes (plaques) in the bacteria lawn.
p.22
Transduction Mechanisms and Terminology
Is T4 a transducing phage?
No, because it degrades host DNA upon infection.
p.16
DNA Packaging in Phages
What initiates T4 DNA replication?
Multiple origins initially.
p.20
Transduction Mechanisms and Terminology
What is a recipient in the context of transduction?
A bacterial strain 'infected' by the transducing phage.
p.33
Bacterial Transformation and Competence
What is bacterial transformation?
The uptake of free DNA from the environment.
p.36
Genetic Analysis of Conjugation
What is the method used for strain construction in this context?
Transduction and transformation.
p.28
Hfr Mapping Techniques
What is the relationship between argH and rif based on the mapping?
argH is closer to rif than to metA.
p.14
Lytic vs. Lysogenic Phage Cycles
What is the final step of lytic phage infection?
Cell lysis and phage release.
p.12
Phage Genetics and Molecular Biology
What types of phages will be covered in this overview?
dsDNA phages and very selected aspects.
p.2
Genetic Analysis of Conjugation
What does a Lac + colony indicate on the original plate?
It correlates with Tra + colonies.
p.29
Genetic Analysis of Conjugation
What does 'rif r' signify in the context of genetic crosses?
It indicates a rifampicin-resistant strain.
p.29
Genetic Analysis of Conjugation
What do the terms 'Donor' and 'Recipient' refer to in genetic crosses?
The Donor is the organism providing genetic material, while the Recipient is the organism receiving it.
p.21
Transduction Mechanisms and Terminology
What type of DNA does a good transducing phage have?
Double-stranded DNA (dsDNA).
p.3
Selection Methods for F' Factors
How does replica plating work?
By using a sterile tool to press onto colonies and then onto a new agar plate.
p.32
Genetic Analysis of Conjugation
What is horizontal gene transfer?
The transfer of genetic material between organisms in a manner other than traditional reproduction.
p.27
Genetic Analysis of Conjugation
What does metA - signify?
Absence of the metA gene.
p.13
Transduction Mechanisms and Terminology
What is the difference between generalized and specialized transduction?
Generalized transduction occurs during the lytic cycle, while specialized transduction is associated with the lysogenic cycle.
p.29
Genetic Analysis of Conjugation
What is required for bacterium survival in genetic crosses?
An even number of crosses (2, 4, 6, etc.).
p.12
Transduction Mechanisms and Terminology
What can happen to host DNA upon infection by some dsDNA phages?
Some may degrade host DNA.
p.31
Genetic Analysis of Conjugation
What can be inferred about the order of genA, trpB, and argC based on the transductant phenotypes?
The order can be determined by analyzing the frequency of different phenotypes in the transductants.
p.18
DNA Packaging in Phages
Why is DNA packaging important after prohead assembly?
It ensures the genetic material is efficiently enclosed for viral infection.
p.10
Phage Genetics and Molecular Biology
What types of genetic materials can phages have?
All kinds of genetic materials.
p.35
Mapping Bacterial Genes via Transduction
What is used as a measure of distance between two markers/genes in transformation mapping?
Co-transformation frequency.
p.10
Phage Genetics and Molecular Biology
What is a characteristic of phages in terms of structure?
They have all kinds of shapes and complexity.
p.33
Bacterial Transformation and Competence
What did Avery, MacLeod, and McCarty demonstrate in 1944?
That DNA is the transforming factor and the genetic material.
p.24
Hfr Mapping Techniques
What is the purpose of using Hfr in mapping mutations?
To perform rough mapping of mutations.
p.23
Transduction Mechanisms and Terminology
How does the frequency of co-transduction relate to the distance between two markers?
The higher the frequency of co-transduction, the shorter the distance between the two markers.
p.34
Bacterial Transformation and Competence
Why is artificially induced competence frequently used in labs?
To transform a strain with a plasmid.
p.8
Phage Genetics and Molecular Biology
What concept related to genetic codons was explored by Crick, Barnett, Brenner, and Watts-Tobin in 1961?
The nature of genetic codon and frameshift mutations.
p.6
Bacterial Transformation and Competence
How does the high salt concentration affect individual cells?
It limits the types of organisms that can survive, allowing only simple organisms to thrive.
p.25
Transduction Mechanisms and Terminology
What is a donor in transduction terminology?
A bacterial strain used to grow/propagate the transducing phage.
p.13
Lytic vs. Lysogenic Phage Cycles
What are the two types of phages based on their infection cycle?
Virulent (lytic) and temperate (lysogenic).
p.20
Transduction Mechanisms and Terminology
What does 'a cross' refer to in transduction?
The process of transduction, mixing the genetic material of a recipient with that of a donor through a phage.
p.32
Genetic Analysis of Conjugation
What is conjugation?
A method of gene transfer in bacteria that involves direct cell-to-cell contact.
p.23
Transduction Mechanisms and Terminology
What is co-transduction?
Mapping by co-transduction involves determining if two markers are co-transducible, indicating they are within a certain distance on the phage chromosome.
p.32
Transduction Mechanisms and Terminology
What is transduction?
The process by which bacteriophages transfer genetic material from one bacterium to another.
p.34
Bacterial Transformation and Competence
What is natural competence in bacteria?
A state where certain bacteria can be transformed at specific stages in their life cycle.
p.1
Selection Methods for F' Factors
What is distal marker selection?
A method used to select for F’ factors by disrupting genes that are far from the origin of transfer.
p.18
DNA Packaging in Phages
What is the prohead in the context of DNA packaging?
It is an intermediate structure formed during the assembly of a bacteriophage.
p.8
Phage Genetics and Molecular Biology
Which scientists received Nobel Prizes for their work related to genetic codons?
Crick (Nobel, 1962) and Brenner (Nobel, 2002).
p.7
Phage Genetics and Molecular Biology
Why are phages important in biology?
They provide some of the best systems to study fundamental biological questions.
p.17
DNA Packaging in Phages
What is the function of the DNA packaging motor in phages?
It carries DNA concatemers to a phage head and stuffs it with DNA until full.
p.24
Hfr Mapping Techniques
What does Hfr stand for in genetic mapping?
Hfr stands for 'high frequency of recombination'.
p.4
Transduction Mechanisms and Terminology
What are the two main types of transduction?
Generalized transduction and specialized transduction.
p.17
DNA Packaging in Phages
What is a concatemer in the context of DNA packaging?
A long continuous molecule of DNA that is made up of multiple copies of the same DNA sequence.
p.1
Hfr Mapping Techniques
What is Hfr mapping?
A technique used for rough mapping of bacterial genes.
p.14
Lytic vs. Lysogenic Phage Cycles
What happens during the assembly stage of lytic phage infection?
New phage particles are assembled.
p.2
Genetic Analysis of Conjugation
What type of strain is used for replica plating in this experiment?
An F - strain (Lac -, Str r).
p.26
Genetic Analysis of Conjugation
What are the genotypes of the donor and recipient in the cross?
Donor: argH + metA - rif S; Recipient: argH - metA + rif R (rif - 8).
p.1
F' Factor and Plasmid Generation
How is an F’ factor generated?
Through the process of conjugation where an F factor integrates into the bacterial chromosome and is excised incorrectly.
p.34
Bacterial Transformation and Competence
Name a gram-negative bacterium that is naturally competent.
Helicobacter pylori or Neisseria spp.
p.29
Genetic Analysis of Conjugation
What is a three-factor cross in genetics?
A genetic cross involving three different genes to analyze their interactions.
p.8
Phage Genetics and Molecular Biology
What significant discovery did Hershey and Chase make in 1952?
Phage genes are encoded by DNA instead of proteins.
p.3
Selection Methods for F' Factors
What is replica plating?
A technique used to transfer colonies of microorganisms from one agar plate to another.
p.21
Transduction Mechanisms and Terminology
What kind of DNA packing mechanisms do good transducing phages have?
Less stringent/specific DNA packing mechanisms.
p.3
Selection Methods for F' Factors
What type of organisms is replica plating commonly used for?
Microorganisms, particularly bacteria and fungi.
p.16
DNA Packaging in Phages
What occurs during Stage 2 of T4 replication?
Additional DNA synthesis by recombination intermediates.
p.19
Transduction Mechanisms and Terminology
What are the possible fates of donor DNA in a recipient cell?
Homologous recombination, degradation, self-replication if plasmids, transposition, etc.
p.34
Bacterial Transformation and Competence
Name a gram-positive bacterium that is naturally competent.
Streptococcus pneumoniae or Bacillus subtilis.
p.34
Bacterial Transformation and Competence
What is artificially induced competence?
A method to make bacteria competent, such as in E. coli.
p.8
Phage Genetics and Molecular Biology
What prestigious award did Hershey and Chase receive in 1969?
They shared the Nobel Prize.
p.21
Transduction Mechanisms and Terminology
What is a key characteristic of a good transducing phage regarding host DNA?
No destruction of host DNA.
p.32
Bacterial Transformation and Competence
What is transformation in bacterial gene transfer?
The process by which bacteria take up free DNA from their environment.
p.23
Genetic Analysis of Conjugation
What are the issues associated with Hfr mapping?
It is not as accurate and not as useful for fine mapping.
p.20
Transduction Mechanisms and Terminology
What is a transductant?
The progeny or recombinant from the cross/transduction.
p.1
F' Factor and Plasmid Generation
What is an F’ factor/plasmid?
A plasmid that contains a portion of the bacterial chromosome.
p.12
Transduction Mechanisms and Terminology
How can dsDNA phages act in relation to host bacteria?
They may act as transducing particles.
p.28
Hfr Mapping Techniques
How can the order of genes be determined?
Through three-factor crosses.
p.1
Genetic Analysis of Conjugation
What is the focus of genetic analysis of conjugation?
Understanding the transfer of genetic material between bacteria.
p.19
Transduction Mechanisms and Terminology
What happens when a phage injects its DNA into a recipient cell?
It injects its DNA content regardless of its origin.
p.4
Phage Genetics and Molecular Biology
What is the role of phages in bacterial research?
Phages are used to study bacterial genetics, evolution, and as potential therapeutic agents.
p.21
Transduction Mechanisms and Terminology
What is an important feature of good transducing phages regarding host range?
They have a broad host range.
p.16
DNA Packaging in Phages
How is the long concatemer packaged in T4 replication?
From a fixed point until the phage head is full.
p.34
Bacterial Transformation and Competence
Which types of bacteria exhibit natural competence?
Both gram-positive and gram-negative bacteria.
p.29
Genetic Analysis of Conjugation
What does the notation 'argH + rif S metA -' represent?
It indicates a specific genetic configuration in a bacterium.
p.18
DNA Packaging in Phages
What occurs after prohead assembly in DNA packaging?
DNA is packed into the prohead.
p.18
DNA Packaging in Phages
What is the role of ATP in DNA packaging after prohead assembly?
ATP provides energy for the molecular motors involved in DNA translocation.
p.33
Bacterial Transformation and Competence
Can bacteria be competent?
Yes, some bacteria can be competent.
p.29
Genetic Analysis of Conjugation
What is the significance of the rif gene's position in genetic crosses?
The rif gene is in the middle to facilitate mapping and understanding of genetic interactions.
p.2
Genetic Analysis of Conjugation
What are the carbon/energy sources used in the replica plating?
Lactose and Streptomycin.
p.23
Transduction Mechanisms and Terminology
How can physical distance between markers be calculated?
By using formulas specific to individual phages.
p.34
Bacterial Transformation and Competence
What is involved in the process of natural competence?
A complicated process involving a few dozen proteins.
p.12
DNA Packaging in Phages
What is a characteristic of some dsDNA phages regarding their packaging mechanisms?
They may have too selective packaging mechanisms.
p.18
DNA Packaging in Phages
What mechanism is involved in the DNA packaging process?
Molecular motors help in the translocation of DNA into the prohead.
p.28
Hfr Mapping Techniques
What are the two possible orders of the genes based on the mapping?
argH -- rif -- metA and rif -- argH -- metA.
p.12
DNA Packaging in Phages
What is DNA packaging related to in phages?
Phage chromosome structure and replication.
p.1
Selection Methods for F' Factors
What role does Rec play in selecting replicons?
Rec is involved in the selection of replicons in the recipient during genetic analysis.
p.34
Bacterial Transformation and Competence
What are two methods used for artificially inducing competence?
Calcium ion induction and electroporation.
p.8
Phage Genetics and Molecular Biology
What role does mRNA play according to Brenner, Jacob, and Meselson in 1961?
mRNA acts as a messenger.
