Horizontal Gene Transfer Flashcards
Bacterial gene transfer by –requires physical contact between cells of the two strains.
conjugation
the process is controlled by genes of extrachromosomal elements
conjugation
the process requires genetic information for transfer which is found in the F plasmid DNA of the donor cell
conjugation
the process is characterized by infection of the donor cell by a bacteriophage
transduction
DNA enters the “recipient” cell via DNA transporters
transformation
DNA is released after the “donor” cell lyses
transformation
transforming elements absorb across the cell membrane
transformation
It is the transfer of DNA between organisms by a manner independent of asexual or sexual reproduction.
horizontal gene transfer
LGT has converted some benign bacteria into – that cause disease.
pathogens
LGT provides for the – of complex traits
rapid evolution
– contributes to antibiotic resistance in many bacterial species.
LGT
LGT allows an organism to instantly acquire whole segments of chromosomes containing –.
multiple, functionally related genes
LGT provides for rapid – evolution
genome
- Drug resistance can evolve rapidly through lateral gene transfer and physicians look to the CDC for warnings and recommendations for treatments in order to best serve their patients.
- Drug resistance can be transmitted through horizontal gene transfer from prokaryotes to humans and the CDC must remain vigilant to decrease the spread of antibiotic resistance among species.
- Drug resistance can evolve rapidly through horizontal gene transfer that stimulates the evolution of pathogens and the CDC tries to prevent the rise of new bacterial species.
- Drug resistance can evolve rapidly through lateral gene transfer and physicians look to the CDC for warnings and recommendations for treatments in order to best serve their patients.
What are the short-term implications of these frequent changes for physicians and clinics that treat sexually transmitted diseases like gonorrhea and for individuals infected with gonorrhea?
- Physicians carefully monitor progress to recovery in their patients.
- Physicians report the occurrence of new, drug-resistant strains to the CDC.
- Physicians give partial antibiotic treatment to patients to develop antibiotic resistant strains for further studies.
- Physicians give up-to-date treatments to their patients.
- Physicians carefully monitor progress to recovery in their patients.
- Physicians report the occurrence of new, drug-resistant strains to the CDC.
- Physicians give up-to-date treatments to their patients.
What are the long-term implications of these frequent changes in treatment recommendations for the patient population?
Select the five correct answers.
- Physicians constantly change recommendations for adequate treatment.
- Physicians provide continued resources for the CDC.
- Physicians limit the horizontal gene transfer.
- Physicians promote the development and spread of antibiotic resistant bacteria.
- Physicians provide continued resources for research institutions to study bacterial antibiotic resistance.
- Physicians study the mechanisms and consequences of lateral gene transfer and its role in the evolution of antibiotic resistance.
- The government supports the funding of basic research.
- Physicians constantly change recommendations for adequate treatment.
- Physicians provide continued resources for the CDC.
- Physicians provide continued resources for research institutions to study bacterial antibiotic resistance.
- Physicians study the mechanisms and consequences of lateral gene transfer and its role in the evolution of antibiotic resistance.
- The goverment supports the funding of basic research.
To integrate an F plasmid’s genes into a host chromosome, there must be DNA recombination at homologous regions on the two circular strands. What is the minimum number of such crossover events needed for integration?
1
– require a supplement to grow
auxotrophs
will grow in the presence or absence of the supplement
prototrophs
Once conjugation begins, the Hfr strain starts transferring the integrated – and a copy of the Hfr chromosome attached to it
F plasmid
The appearance of prototrophic colonies in an interrupted conjugation experiment indicates that a wild-type locus (from the Hfr donor) has entered the recipient cell and – into its genome.
recombined
– is a technique that allows the same bacterial colonies to be plated onto different media.
Replica plating
least frequent exconjugant genotype has the – crossovers
most
During conjugation, cells gain genes in the order they occur in the donor cell chromosome. Genes that are – the origin of transfer will be transferred first.
near
TThe distance between genes on the gene map is measured in – because the distance between genes is measured by the time it takes for the gene to be transferred from the host cell into the recipient cell. This distance can be determined by looking at the first appearance of each phenotype on the graph.
minutes
What role does the blender play in the experiment? shears the sex pili of
conjugants
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? to eliminate –
non-conjugated F- cells
Conjugation between an Hfr cell and an F− cell does not usually result in conversion of exconjugants to the donor state. Occasionally however, the result of this conjugation is two Hfr cells. Transfer of the – of the Hfr cell and recombination of the entire F plasmid DNA sequence into the recipient chromosome could convert an F− cell into an Hfr cell.
entire chromosome
only – involves the transfer of DNA from an Hfr cell to an F- cell
conjugation
T/F: conjugation, transduction, and transformation can be used to map the order of genes on a bacterial chromosome
true
T/F: Bacteria can acquire antibiotic resistance by a variety of methods, including random mutation and genetic transfer by transformation, transduction, or conjugation.
true
A – cotransduction frequency indicates that two loci are close together and thus more likely to move as a unit to the recipient cell
large
Bacteriophages bind the bacteria host cell and inject their DNA into the host cell. The phage then –, which prevents its degradation.
circularizes
In the – cycle, new bacteriophages are made and the host cell is lysed.
lytic
In the – cycle, the phage DNA integrates into the host cell chromosome, and the phage DNA is replicated with the bacterial cell DNA as the cell divides.
lysogenic
In which cycle is phage DNA transcribed and translated to make new phage particles (phage DNA is packaged into phage heads)?
lytic
During transduction, fragments of bacterial DNA are – packaged into the phage head.
randomly
During transduction, phages package fragments of bacterial DNA into new –. This bacterial DNA can be transferred to another bacteria cell during the next phage infection.
phage heads
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. Then, a – of crossovers between the donor segment and the recipient
pair (or even number)
a population – if its genotype frequencies differ from those predicted by the Hardy-Weinberg principle.
may be evolving
assuming random mating, each gamete’s chance of carrying an allele equals –
that allele frequency
square root method can only be used when the population is in – and the two alleles in question exhibit a dominant and recessive relationship.
Hardy-Weinberg equilibrium
