Shared Flashcard Set

Details

Chapter 9: Genetic Mapping in Bacteria and Bacteriophages
Chapter 9: Genetic Mapping in Bacteria and Bacteriophages Notecards
80
Biology
Undergraduate 3
11/11/2012
Click here to study/print these flashcards.

Create your own flash cards! Sign up here.

Additional Biology Flashcards

 

 

Cards

Term
What are the three methods for gene transfer in bacteria? In all three cases what is the direction?
 Definition
1) Transformation
2) Conjugation
3) Transduction
4) Unidirectional
Term
What characteristics of E. coli make it different than eukaryotes?
 Definition
1) No nuclear membrane
2) No formal nuclear division
3) No metaphase
4) No highly condensed chromosomes like in eukaryotes
5) Often have extrachomosomal DNA called plasmids
Term
Bacteria often have extrachromosomal DNA called __________.
 Definition
1) Plasmids
Term
__________ are small circular double-stranded molecules with an origin of DNA replication and capable of self-replication.
 Definition
1) Plasmids
Term
Plasmids often carry one or more genes for resistance to __________.
 Definition
1) Antibiotics
Term
A large plasmid found in E. coli cells is called __________-__________ or __________-__________.
This plasmid carries genes that enable it to make tube-like structures (__________) on the surface of the E. coli cell.
 Definition
1) F-factor
2) Sex-factor
3) Pilus
Term
A cell containing the F-factor and capable of making pili is called a __________ or __________ cell.
These cells make contact with __________ or __________ cells and establish a connection using a __________.
Plasmids, like the F-factor, capable of mediating conjugation are called __________ __________; not all plasmids can do this.
During mating, a copy of the sex-factor plasmid is transferred to the __________ cell using the __________ __________.
The F-factor replicates by a rolling circle mechanism and the resulting single-stranded tail of DNA is transferred to the __________ cells creating a __________ __________ in the recipient cell. This converts an __________ cell to an __________ cell.
 Definition
1) F+
2) Male
3) F-
4) Female
5) Pilus
6) Conjugative plasmids
7) F-
8) Conjugation tube
9) F-
10) DS DNA
11) F-
12) F+
Term
The simplest bacterial transposons are called __________ __________.
 Definition
1) Insertion sequences
Term
What are the three major characteristics of insertion sequences?
 Definition
1) Have short inverted repeat sequences at their ends
2) Have very short direct repeats at the site of insertion
3) Have a gene in the middle for an enzyme called transposase, that catalyzes their movement from on e location to another
Term
Complicated transposons often have __________-__________ __________ in addition to the transposase gene.
 Definition
1) Antibiotic-resistance genes
Term
__________ can insert themselves into any DNA, chromosomes, or plasmid that may be present in the bacterial host cell.
 Definition
1) Transposons
Term
When the same transposons are present in the __________ and __________ of a bacterial host cell, they may recombine with each other, integrating the plasmid into the chromosomes and creating a fused molecule called a __________; the process is __________.
 Definition
1) Plasmid
2) Chromosome
3) Cointegrate
4) Reversible
Term
Another recombination event that takes place in bacteria can result in the release of the __________ from the chromosome.
Often it occurs at specific sequences within the two recombining DNAs by a special enzyme called __________-__________ __________.
Unlike normal homologous recombination, site-specific recombination can only occur at very specific __________ sequences.
 Definition
1) Plasmid
2) Site-specific recombinase
3) Short
Term
The term __________ is used for a DNA element that has a gene for site-specific recombinase and the target sequence for the recombination enzyme.
The elements that integrons acquire by site-specific recombination are called __________.
 Definition
1) Integron
2) Cassettes
Term
By __________-__________ __________ between similar sequences, a self-replicating piece of DNA like a __________ may pick up multiple pieces of DNA each carrying a different antibiotic resistance gene.
The result is a multiple-drug-resistance plasmid which transfers the resistance genes together to different bacteria in a single mating event.
 Definition
1) Site-specific recombination
2) Plasmid
Term
On an agar plate, each cell divides many times to produce a clump with millions of cells known as a __________.
All cells in a colony are genetically alike - __________.
__________ __________ is a defined medium where the identity of all ingredients and concentrations is known; E. coli can grow on such a medium.
Mutants that require ingredients added to the minimal medium in order to grow are called __________ __________ (wild type = __________).
The added ingredient can be absolutely anything not present in the minimal medium that the mutant cannot make on its own.
The progeny of a bacterial cross are usually grown in a rich medium (also called "__________ or __________-__________" medium) so that all genotypes can grow up and make colonies.
Each colony can then be analyzed by "__________-__________" onto different indicator plates.
 Definition
1) Colony
2) Clones
3) Minimal medium
4) Auxotrophic mutants
5) Prototrophic
6) Complete
7) Non-selective
8) Replica-plating
Term
A minimal medium that has some known added ingredient is known as a __________ __________ on which the wild type and mutant bacteria with a certain phenotype can grow.
 Definition
1) Selective medium
Term
In bacteria, usually only a DNA fragment that is smaller than the whole genome is transferred to a recipient cell resulting in a __________ __________.
 Definition
1) Partial diploid
Term
__________ involves the uptake of a free DNA fragment by a cell (provided first line of evidence indicating that __________ is the genetic material).
 Definition
1) Transformation
2) DNA
Term
__________ involves direct mating between two bacterial cells using a conjugation tube.
 Definition
1) Conjugation
Term
__________ involves the transfer of some DNA from one bacterial cell to another by a bacterial virus (__________).
 Definition
1) Transduction
2) Bacteriophage
Term
Transfer of DNA from one bacterium to another by free DNA fragments is called __________ __________.
Transformation can be used for the __________ __________ of genes.
The genotype / phenotype is changed due to uptake of free DNA - __________.
Some bacteria undergo this process spontaneously; most do not.
 Definition
1) Bacterial transformation
2) Genetic mapping
3) Transformants
Term
Both __________ __________ and __________-__________ distances can be determined by gene transformation.
 Definition
1) Gene linkage
2) Gene-gene distances
Term
Gene order can be determined by looking at __________-__________ frequencies for various genes.
 Definition
1) Co-transformation
Term
__________ in bacteria involves the unidirectional transfer of DNA from one bacterium (male cell, F+) to another bacterium (female cell, F-).
 Definition
1) Conjugation
Term
In the F+ E. coli population, there are some cells that have 1000x greater ability to transfer chromosomal markers; these cells are known as __________ __________ __________ strains.
__________ are DNA molecules that can exist within our outside the host chromosome.
 Definition
1) High frequency recombinants
2) Episomes
Term
Transfer of an entire chromosome takes about __________ minutes. If one breaks the __________ __________ at various times after the start of mating, one can tell the order in which donor genes are being transferred. This is why the E. coli genetic map is in units of minutes.
Genes __________ to the selected marker will be a few minutes away, while genes __________ on the chromosome will have more time apart.
This is how after the start of __________, blending is done and the frequency of recombinants for various markers can be determined.
 Definition
1) 100
2) Conjugation bridge
3) Closest
4) Farther
5) Conjuation
Term
Bacterial crosses are almost always between __________ complete and incomplete genome; __________ recombinants are not viable.
One gets __________ viable and non-viable recombinant. Both __________ cells are also killed by the selection applied.
 Definition
1) One
2) Reciprocal
3) One
4) Parental
Term
The genetic map of E. coli is __________.
 Definition
1) Circular
Term
__________ in bacteria involves the transfer of genes by means of a bacteriophage. Recipient cells are called __________.
 Definition
1) Transduction
2) Transdctants
Term
What are the two types of transduction?
 Definition
1) General
2) Specialized
Term
__________ are viruses that infect bacteria.
 Definition
1) Phages
Term
DNA viruses are usually __________-stranded, a few are __________-stranded.
 Definition
1) Double
2) Single
Term
What are the two viruses of E. coli that have been studied heavily?
 Definition
1) T4
2) Lambda
Term
All viruses have a __________ __________.
 Definition
1) Protein coat
Term
What are the two main life cycles of phages?
 Definition
1) Lytics
2) Lysogenic
Term
A __________ phage life style involves attachment to the host bacterium, injection of viral DNA, breakdown of host DNA, replication of phage DNA, head / tail synthesis, assembly of the complete viruses, and __________ (rupture) of the host cell and release of progeny viruses.
The cycle is completed by __________ __________.
 Definition
1) Lytic
2) Lysis
3) Virulent phages
Term
The suspension of intact and broken cells in addition to free phages is known as a __________ __________.
 Definition
1) Phage lysate
Term
The lyosgenic life style of a phage is carried out by __________ __________.
The incoming phage DNA has two choices: either go through the lytic cycle as a __________ __________ or recombine into the host chromosome and become __________.
 Definition
1) Temperate phages
2) Virulent phage
3) Silent
Term
The silent prophage is maintained by a __________ __________ (__________ protein, the only phage gene that is active in the prophage stage).
Occasionally, the repressor control breaks down, the __________ cycle is induced, and the progeny phages come out.
 Definition
1) Phage protein
2) Repressor
3) Lytic
Term
In __________ __________, any bacterial gene can be picked up by the phage vector and transferred.
In __________ __________, very few bacterial genes (those near the site of __________ of the temperate phage into the host chromosome) can be moved.
 Definition
1) Generalized transduction
2) Specialized transduction
3) Insertion
Term
In E. coli, generalized transduction is performed by the phage __________. Normally, this phage exists in the __________ state in E. coli as a prophage. Occasionally, the lytic cycle occurs and the host chromosome is broken down.
Sometimes, a piece of bacterial chromosomes gets packaged in the phage __________ (instead of the phage __________).
One phage in every 10^5 is a __________ __________.
Since the phage head can accommodate only a __________ chunk of the bacterial chromosome, __________ mapping works over small distances only like transformation).
 Definition
1) P1
2) Lysogenic
3) Head
4) Genome
5) Transducing phage
6) Small
7) Transduction
Term
__________ is used for long-range analysis and __________ for fine-structure analysis.
 Definition
1) Conjugation
2) Transduction
Term
__________ __________ can not only tell which genes are close to each other but also tell their map order and distances.
 Definition
1) Transduction mapping
Term
All recombination requires __________ (or multiples of) crossovers.
__________ number crossovers lineraize the chromosome and are lethal.
 Definition
1) Two
2) Odd
Term
__________ phage DNA in the phage head exists as a __________ piece of DNA with sticky ends called __________ __________.
Upon infection, the __________ __________ are joined together to make a circular double-stranded molecule; this phage DNA circle recombines (integrates) into the bacterial chromosome by a __________ crossover.
The recombination occurs at a specific location in the E. coli chromosome the lambda __________ site.
Upon induction of the __________ cycle, the lambda phage loops out and __________-__________ __________ excises the phage DNA as a separate circular chromosome.
 Definition
1) Lambda
2) Linear
3) Cos sites
4) Sticky ends
5) Single
6) Att
7) Lytic
8) Site-specific recombination
Term
__________ __________ in bacteriophages is very similar to eukaryotic crosses.
It involves mating between two whole genomes in which the products are two __________ and __________; this is done through __________ __________ __________.
Both products are __________ (unlike those in bacteria).
 Definition
1) Genetic mapping
2) Parentals
3) Recombinants
4) Reciprocal crossing over
5) Viable
Term
Growth of phages can be monitored because they devour their host cells producing small clearing in the bacterial lawn called phage __________; each is produced by a __________ phage.
All phages in a plaque are not __________.
 Definition
1) Plaque
2) Single
3) Identical
Term
What are the two ways which make T4 DNA peculiar? How does this occur?
 Definition
1) Has terminal redundancy
2) Map is circularly permuted
3) They are created due to the phage heads being packed from very long multimeric DNA by a headful mechanism
Term
A __________ __________ is a clump of cells on a nutrient agar plate descended from a single bacterial cell.
 Definition
1) Bacterial colony
Term
The __________ __________ is a medium with chemically defined ingredients.
 Definition
1) Minimal medium
Term
A __________ __________ or complete medium is one with undefined substances derived from the breakdown of yeast cells, beef broth, etc.
 Definition
1) Rich medium
Term
A __________ __________ is a strain that can grow on a minimal medium.
 Definition
1) Prototrophic strain
Term
An __________ __________ cannot grown on minimal medium (because it has one ore more mutations for essential components that are lacking in minimal medium.
 Definition
1) Auxotrophic strain
Term
__________ is a genetic change that occurs in a bacterium due to the uptake of DNA.
 Definition
1) Transformation
Term
__________-__________ is the transfer of two or more traits together during one transformation event.
 Definition
1) Co-transformation
Term
__________ are cells that have undergone transformation.
 Definition
1) Transformants
Term
__________ __________ are bacteria that can undergo transformation.
 Definition
1) Competent bacteria
Term
__________ __________ is a DNA molecule that has different genetic information in the two strands.
 Definition
1) Heteroduplex DNA
Term
__________ __________ are genes that are being selected for in the recombinants.
 Definition
1) Selected markers
Term
__________ __________ are genes that are checked for co-transfer with the selected marker.
 Definition
1) Unselected markers
Term
__________ is the transfer of DNA from one bacterium to another through cell-to-cell contact. The DNA donor cell is called the male strain (F+ or Hfr) and the recipient cell is called the female strain (F-)
 Definition
1) Conjugation
Term
The __________ __________ is a male strain that carries a fertility factor (F plasmid). A piece of DNA separate from the bacterial chromosome.
 Definition
1) F+ strain
Term
The __________ __________ is a male strain in which the F plasmid has recombined into the host chromosome.
 Definition
1) Hfr strain
Term
An __________ is a piece of DNA in a bacterial cell that can exist as a free-self-replicating entity or can become integrated into the chromosome of the cell.
 Definition
1) Episome
Term
An __________ __________ is an F-factor that has picked some of the chromosomal genes.
 Definition
1) F' factor
Term
__________ is the transfer of a few chromosomal genes from one bacterium to another by the F' factor
 Definition
1) Sexduction
Term
A __________ is a bacterial virus.
 Definition
1) Bacteriophage
Term
__________ is the transfer of bacterial genes from one cell to another through a bacteriophage intermediary.
 Definition
1) Transduction
Term
__________ __________ is when any chromosomal gene of a bacterium can be transferred by a bacteriophage.
 Definition
1) Generalized transduction
Term
__________ __________ is when only a limited set of genes can be transferred from one bacterium to another by a bacteriophage.
 Definition
1) Specialized transduction
Term
The __________ __________ is one kind of a life cycle of a bacteriophage. Infection leads to the production of many progeny viruses, lysis of the host cell and release of the progeny viruses.
 Definition
1) Lytic cycle
Term
A __________ __________ is a bacteriophage capable of lytic growth.
 Definition
1) Virulent phage
Term
__________ is another kind of life cycle of a bacteriphage where the incoming viral DNA integrates into the host chromosome and becomes quiescent. The host cell is not destroyed and the viral DNA is replicated along with the whole host chromosome.
 Definition
1) Lysogeny
Term
A __________ __________ is a bacteriophage capable of lysogenic growth.
 Definition
1) Temperate phage
Term
A __________ is a temperate phage in its integrated silent state
 Definition
1) Prophage
Term
A __________ __________ __________ is a mutation that is lethal under certain growth conditions and non-lethal under others.
 Definition
1) Conditional lethal mutation
Term
A __________ __________ __________ __________ is a site within a gene where disproportionate amount of mutations are found to occur.
 Definition
1) Hot spot of mutation
Term
__________ __________ is the rescue of a mutation by another mutation. Neither mutant can grow alone, but when together in the same cell (on the same chromosome [cis-state] or on different chromosomes [trans-state]) the two mutants can grow.
 Definition
1) Genetic complementation
Term
A __________ is a unit of function (synonymous with a gene).
 Definition
1) Cistron
Supporting users have an ad free experience!