Term
| What is the difference in gene transfer in eukaryotes vs. prokaryotes? |
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Definition
-in eukaryotes it is an essential part of life (sexual reproduction)
-in prokaryotes it is not essential (occurs either through binary fission or transduction, conjugation, transformation) |
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Term
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Definition
| movement of genetic information between organisms |
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Term
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Definition
| combining of genes from 2 different cells, increases genetic diversity |
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Term
| What are the 2 types of gene transfer? |
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Definition
1. vertical gene transfer (sexual reproduction, binary fission)
2. lateral/horizontal gene transfer-transformation, conjugation, transduction |
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Term
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Definition
| genes are passed from parents to offspring |
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Term
| lateral (horizontal) gene transfer |
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Definition
| genes are passed to other microbes from the same generation |
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Term
| 3 methods of horizontal gene transfer |
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Definition
| transformation, transduction, conjugation |
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Term
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Definition
| change in an organism's characteristics through transfer of naked DNA |
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Term
| Griffith's Experiment with Pneumococci |
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Definition
-1928
-studied 2 types: encapsulated, virulent (S type) and not encapsulated, nonvirulent (R type)
-discovered that if the nonvirulent strain was mixed with heat killed virulent strains and injected into mice, the mice would die
-showed that naked DNA was taken up my nonvirulent cells and transformed into virulent cells |
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Term
| Avery, MacLeod, McCarty experiment |
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Definition
-1944
-discovered the substance responsible for transformation is DNA |
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Term
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Definition
| ability of a cell to take up naked DNA |
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Term
| How are some ways that cells become competent? |
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Definition
| naturally, chemically induced, heat shock |
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Term
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Definition
| protein released which facilitates entry of DNA into bacteria |
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Term
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Definition
| cut double stranded naked DNA into smaller pieces (7,000-10,000 nucleotides) for entrance into cells |
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Term
| Does double or single stranded DNA enter the cell for transformation? |
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Definition
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Term
| What is the significance of transformation? |
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Definition
-rarely seen in nature, probably following breakdown of dead organisms
-can be used in lab to study locations of genes on chromosomes
-can be used to produce recombinant DNA |
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Term
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Definition
| transfer of DNA from 1 bacterium to another via a bacteriophage |
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Term
| Who discovered transduction and in what year? |
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Definition
-Joshua Lederberg & Norton Zinder
-1952 |
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Term
| structure of a bacteriophage |
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Definition
| core of nucleic acid and protein coat |
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Term
| What are the 2 types of bacteriophages? |
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Definition
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Term
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Definition
capable of causing infection & death of cell
-follows lytic cycle |
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Term
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Definition
| sequence of events in which a bacteriophage infects a bacterial cell, replicates, and eventually causes lysis of the cell |
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Term
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Definition
phage that ordinarily does not cause a disruptive infection
-phage is incorporated in bacterial DNA and replicated (prophage)
-follows lysogenic cycle |
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Term
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Definition
phage that ordinarily does not cause a disruptive infection
-phage is incorporated in bacterial DNA and replicated (prophage)
-lysogenic although can eventually become lytic |
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Term
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Definition
| the DNA of a lysogenic phage that has integrated into the host cell chromosome |
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Term
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Definition
| ability of temperate bacteriophages to persist in a bacterium by the integration of viral DNA into the host chromosome and without the replication of new viruses or cell lysis |
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Term
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Definition
transduction in which the phage particle transduces specific genes from one bacterial cell to another
-bacterial DNA transduced is limited to one or a few genes lying adjacent to the prophage |
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Term
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Definition
| transduction in which each bacterial fragment from the host cell has an equal chance of accidentally becoming part of phage particles during phage's replication, and then transfered to new bacteria |
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Term
| What is the significance of transduction? |
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Definition
-allows bacterial cells to acquire new/variable traits
-provides way to study gene linkage
-shows close evolutionary relationship b/w prophage & host
-prophage in host cell suggests possible similar mechanism for viral origin of cancer |
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Term
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Definition
| transfer of genetic info from one bacterial cell to another by means of conjugation pili |
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Term
| How does conjugation differ from transduction and transformation? |
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Definition
-requires direct contact between donor & recipient
-transfers larger amounts of DNA |
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Term
| Who discovered conjugation and in what year? |
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Definition
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Term
| Lederberg's experiment for conjugation |
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Definition
-used 2 different auxotrophic E. coli strains, would not grow on minimal media
-mixed the 2 strains and then some grew on the minimal media, had acquired the ability to synthesize substances needed
-showed that conjugation had occurred & genes were shared |
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Term
| What are the 3 methods for conjugation? |
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Definition
1. F+ with F-
2. Hfr with F-
3. F' with F- |
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Term
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Definition
| cells that contain the fertility plasmid |
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Term
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Definition
| strain of F+ in which the F plasmid is incorporated into the bacterial chromosome |
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Term
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Definition
| F plasmid that has been imprecisely separated from the bacterial chromosome and so it carries a fragment of the bacterial chromosome |
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Term
| What does an F+ cell and an F- cell make? |
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Definition
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Term
| What is transferred when an F+ cell and an F- conjugate? |
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Definition
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Term
| What is transferred when an HFr and F- cell conjugate? |
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Definition
| the initiating segment of F plasmid and variable quantity of chromosomal DNA |
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Term
| What does conjugation between Hfr and F- result in? |
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Definition
| an F- cell with variable quantity of chromosomal DNA |
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Term
| What is transferred during conjugation between an F' cell and a F- cell? |
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Definition
| F' plasmid and some chromosomal genes it carries with it |
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Term
| What is the product of conjugation between F' and F- cells? |
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Definition
| F' cell with some duplicate gene pairs; one on chromosome, one on plasmid |
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Term
| What is the significance of conjugation? |
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Definition
-important in creating genetic diversity b/c large amount of DNA transferred
-linear transfer useful in chromosome mapping |
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Term
| What is the significance of conjugation? |
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Definition
-important in creating genetic diversity b/c large amount of DNA transferred
-linear transfer useful in chromosome mapping |
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Term
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Definition
| bacteria that have the ability to form F pilus and transfer into species other than their own kind, sometimes even eukaryotes |
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Term
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Definition
| plasmids that carry genes that provide resistance to various antibiotics or toxic metals |
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Term
| What are the 2 components of resistance plasmids? |
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Definition
-resistance transfer factor
-resistance genes |
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Term
| resistance transfer factor |
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Definition
| component of resistant plasmids that implements transfer of resistance genes by conjugation of the plasmid |
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Term
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Definition
| component of resistance plasmids that confer resistance to various antibiotics or toxic metals |
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Term
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Definition
| pieces of DNA isolated from soil bacteria and attached to harmless E. coli in order to displace plasmids with harmful genes, leaving the pathogens now harmless |
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Term
| Why are displacins a better solution than antibiotics? |
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Definition
| because displacins do not produce the "vacuum effect" that antibiotics do, rather they displace bacterial plasmids instead of destroying bacteria |
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Term
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Definition
| ability of genetic sequence to move from one location to another |
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Term
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Definition
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Term
| What does an insertion sequence contain? |
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Definition
-gene that codes for enzymes needed for transposition
-surrounded on either side by inverted repeats |
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Term
| What is the simplest type of transposable element? |
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Definition
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Term
| What does a transposon contain? |
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Definition
-genes that code for enzymes needed for transposition
-also one or more other genes (toxic production or R genes) |
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Term
| How can transposons disrupt gene function? |
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Definition
| by randomly inserting itself into bacterial chromosome or another plasmid, however usually it inserts BETWEEN genes rather than within |
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Term
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Definition
Won Nobel Prize for work on transposons, using corn
-1983 |
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Term
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Definition
Belgian scientist, observe that some strains of E. coli release protein that inhibits growth of other strains of E. coli-->colicins/bacteriocins
-1925 |
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Term
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Definition
| proteins released by certain bacteria that inhibit growth in other strains of the same species or closely related species |
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Term
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Definition
| plasmid that directs production of a bacteriocin |
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Term
| What are some various mechanisms by which bacteriocins inhibit growth of other strains of same bacteria/closely related species of bacteria? |
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Definition
-can enter bacterial cell and destroy DNA
-can arrest protein synthesis by disrupting ribosome structure
-can inhibit active transport or increase membrane permeability |
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Term
| What are some various mechanisms by which bacteriocins inhibit growth of other strains of same bacteria/closely related species of bacteria? |
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Definition
-can enter bacterial cell and destroy DNA
-can arrest protein synthesis by disrupting ribosome structure
-can inhibit active transport or increase membrane permeability |
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Term
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Definition
| purposeful manipulation of genetic material to alter the characteristics of an organism in a desired way |
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Term
| What are the 6 different types/functions of plasmids? |
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Definition
1. F (fertility) plasmid-direct synthesis of proteins for conjugation pili
2. R (resistance) plasmids-carry genes for antibiotic resistance
3. Bacteriocinogens-direct synthesis of bacteriocins
4. virulence plasmids-cause disease signs/symptoms
5. tumor-inducing plasmids-cause tumor formation in plants
6. plasmids for catabolism-contain genes for catabolic enzymes |
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Term
| What are the effects of transformation? |
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Definition
-transfers less than 1% of cell DNA
-requires competence factor |
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Term
What are the effects of transduction in general?
specialized?
generalized? |
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Definition
transduction-transfer is effected by bacteriophage
specialized-only genes near prophage are transfered
generalized-fragments of host DNA of various lengths & numbers are packaged in viral head |
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Term
What are the effects of conjugation?
F+ conjugation?
HFr conjugation?
F' conjugation? |
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Definition
conjugation-transfer is effected by a plasmid
F+-a single plasmid is transfered
HFr-an initiating segment of a plasmid and a linear sequence of bacterial DNA that follows the initiating sequence are transferred
F'-a plasmid and whatever bacterial genes that adhere to it when it leaves the bacterial DNA are transferred |
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Term
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Definition
| type of genetic engineering that involves the coupling of genes from 2 different operons so that both genes are regulated under 1 operon, saves time, done in lab only |
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Term
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Definition
-type of genetic engineering
-cell wall is gone & two different strains of the same species fuse & genetic recombination is forced, occurs in nature but protoplast fusion greatly increased the rate at which is happens
- |
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Term
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Definition
-type of genetic engineering
-plasmids or bacteriophages carrying a specific gene are induced to reproduce at a rapid rate inside the host cell |
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Term
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Definition
| -DNA that contains information from 2 different species, one of most useful techniques of genetic engineering |
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Term
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Definition
| state of permanently changing an organism's characteristics by integrating foreign DNA (genes) into the organism |
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Term
| What are the 3 processes involved in making recombinant DNA? |
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Definition
-manipulation of DNA in vitro (outside cells)
-recombination of another organism's DNA with bacterial DNA in a phage or a plasmid
-the cloning, or production of many genetically identical progeny, or phages or plasmids that carry foreign DNA |
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Term
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Definition
| a self-replicating carrier of DNA; usually a plasmid, bacteriophage, or eukaryotic virus |
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Term
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Definition
| a hybrid cell resulting from the fusion of a cancer cell with another cell, usually an antibody-producing white blood cell |
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Term
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Definition
| a single, pure antibody produced in the laboratory by a clone of cultured hybridoma cells |
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