126 - Bacterial Genetics

Question	Answer
What are competent bacteria able to bind and import?	Short pieces of environmental naked bacterial chromosomal DNA (from bacterial cell lysis).
The transfer and expression of newly transferred genes is called what?	Transformation
Transformation is a feature of many bacteria, especially what bacteria?	A feature of many bacteria, especially S pneumoniae, H influenzae type B, and Neisseria (Mnemonic - SHiN).
What DNA can be used for Transformation?	Any DNA can be used.
What would cause no transformation to be seen?	Adding deoxyribonuclease to environment will degrade naked DNA in medium leading to no transformation seen.
Image: Capture (image/jpeg)	Transformation
F+ plasmid contains genes required for what?	F+ plasmid contains genes required for sex pilus and conjugation.
Bacteria without F+ plasmid are termed what?	Bacteria without this plasmid are termed F–
Explain F+ × F- Conjugation	F+ plasmid contains genes required for sex pilus and conjugation. Bacteria without this plasmid are termed F–. Sex pilus on F+ bacterium contacts F− bacterium. A single strand of plasmid DNA is transferred across the conjugal bridge (“mating bridge”). No transfer of chromosomal DNA.
Image: Capture (image/jpeg)	F+ × F- Conjugation
Image: Capture (image/jpeg)	Hfr × F– Conjugation
Explain the transfer of chromosomal DNA in F+ × F- Conjugation	No transfer of chromosomal DNA.
In F+ × F– Conjugation, A single strand of what is transferred across the conjugal bridge (“mating bridge”)	A single strand of plasmid DNA is transferred across the conjugal bridge (“mating bridge”)
In F+ × F– Conjugation, A single strand of plasmid DNA is transferred across what?	A single strand of plasmid DNA is transferred across the conjugal bridge (“mating bridge”)
In Hfr × F– Conjugation, F+ plasmid can become incorporated into what?	F+ plasmid can become incorporated into bacterial chromosomal DNA, termed highfrequency recombination (Hfr) cell.
In Hfr × F– Conjugation, there is transfer of what?	Transfer of leading part of plasmid and a few flanking chromosomal genes.
In Hfr × F– Conjugation, High-frequency recombination may do what?	High-frequency recombination may integrate some of those bacterial genes
In Hfr × F– Conjugation, what is the end result for the recipient cell?	The recipient cell remains F– but now may have new bacterial genes.
What is described below? Sex pilus on F+ bacterium contacts F− bacterium. A single strand of plasmid DNA is transferred across the conjugal bridge (“mating bridge”). No transfer of chromosomal DNA.	F+ × F– Conjugation
What is described below? Transfer of leading part of plasmid and a few flanking chromosomal genes. High-frequency recombination may integrate some of those bacterial genes. The recipient cell remains F– but now may have new bacterial genes.	Hfr × F– Conjugation
Generalized Transduction is what kind of event?	A “packaging” event.
Specialized Transduction is what kind of event?	An “excision” event.
In Generalized Transduction, what infects bacterium, leading to cleavage of bacterial DNA?	Lytic phage infects bacterium, leading to cleavage of bacterial DNA.
In Generalized Transduction, Lytic phage infects bacterium, leading to what?	Lytic phage infects bacterium, leading to cleavage of bacterial DNA.
In Generalized Transduction, what may happen to parts of bacterial chromosomal DNA?	Parts of bacterial chromosomal DNA may become packaged in phage capsid.
In Generalized Transduction, Parts of bacterial chromosomal DNA may become packaged in what?	Parts of bacterial chromosomal DNA may become packaged in phage capsid.
In Generalized Transduction, phage infects what? Resulting in what?	Phage infects another bacterium, transferring these genes.
Image: Capture (image/jpeg)	Generalized Transduction A “packaging” event
Image: Capture (image/jpeg)	Specialized Transduction An “excision” event.
In Specialized Transduction, Lysogenic phage infects what, and viral DNA incorporates into what?	Lysogenic phage infects bacterium; viral DNA incorporates into bacterial chromosome.
In Specialized Transduction, When phage DNA is excised, what may be excised with it?	When phage DNA is excised, flanking bacterial genes may be excised with it.
In Specialized Transduction, DNA is packaged into what and can infect another bacterium?	DNA is packaged into phage capsid and can infect another bacterium.
In Specialized Transduction, Genes for what 5 bacterial toxins are encoded in a lysogenic phage?	Group A strep erythrogenic toxin, Botulinum toxin, Cholera toxin, Diphtheria toxin, Shiga toxin. (Mnemonic- ABCD'S)
Recall the image for Transformation	Image: Capture (image/jpeg)
Recall the image for F+ × F- Conjugation	Image: Capture (image/jpeg)
Recall the image for Hfr × F– Conjugation	Image: Capture (image/jpeg)
Recall the image for Generalized Transduction	Image: Capture (image/jpeg)
Recall the image for Specialized Transduction	Image: Capture (image/jpeg)

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126 - Bacterial Genetics

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	Created by Victoria Wright over 7 years ago