Data

Copy and paste the text below. It is read-only. Select All

Prokaryote A class of organisms whose DNA is not enclosed in a membrane-bounded nucleus Bacteriophage A virus that parasitizes bacteria Phage Recombination When two different genotypical phages infect the same bacterial cell Plating Process in which a small amount of a liquid culture is pipetted onto a petri plate containing solid agar medium and spread evenly on the surface with a sterile spreader Colony Mass that becomes visible to the naked eye when there are mpre than 10⁷ cells Cell Clones Members of a colony that have a single genetic ancestor Prototrophic Wild-type bacteria that can grow and divide on minimal medium Minimal Medium A substrate containing only inorganic salts, a carbon source for energy, and water Auxotrophic Mutants that will not grow unless the medium contains one or more specific cellular building blocks such as adenine, threonine, or biotin Resistant Mutants Can divide and form colonies in the presence of the inhibitor (ex, the inhibitor could be an antibiotic) Genetic Markers Marker alleles that keep track of genomes and cells in experiments Conjugation The physical union of bacterial cells Donor The cell that transfers its genome Recipient The cell that takes up the transferred DNA Fertility Factor (F) The hereditary state of donor ability F+ Strains that carry F and can donate F- Strains that lack F and cannot donate Plasmid Small, nonessential circular DNA molecule Rolling Circle Replication The F DNA in the donor cell makes a single-stranded copy of itself in a peculiar mechanism Hfr Strain A strain that produces 1000 times as many recombinants as a normal F+ strain. It promotes a high frequenct of recombination. Interrupted Mating At specific times after mixing, the procedure of removing samples and putting them in a kitchen blender to separate the mating cell pairs Exconjugants Cells bearing a donor allele that must have taken part in conjugation Origin (O) The fixed point at which single-stranded DNA transfer begins Terminus The end represented by the last added monomer in the unidirectional synthesis such as RNA or polypeptide Endogenote F-, recombination takes place between this complete genome and an exogenote Exogenote Hfr, recombination takes place between this incomplete genome and an endogenote Merozygote The cell at this stage has two copies of one segment of DNA: one copy is part of the endogenote and the other copy is part of the exogenote. The cell is a partial diploid Unselected Markers In a bacterial recombination experiment, an allele scored in progeny for the frequenct of its cosegreation with a linked selected allele F' Plasmid An F plasmid carrying bacterial genomic DNA R Plasmid The vectors carrying multiple resistances to antibiotics Transposon Unique segments of DNA that can move around to different sites on the genome Transformation If the donor DNA is of a different genotype from that of the recipient, the genotype of the recipient can become permanently changed Double Transformation When two closely located donor genes, both may be carried on the same piece of transforming DNA Lysis The breaking-open process of the bacterial cell wall after bacteriophage infection Lysate The population of the phage progeny Plaque A clear area in the opaque lawn of bacteria covering the surface of a plate of solid medium Mixed Infection (Double Infection) The infection of a bacterial culture with two different phage genotypes Selective System Only the desired rare event can produce a certain visible outcome Screen A system in which large numbers of individuals are visually scanned to seek the rare "needle in the haystack" Transduction Phages pick up bacterial genes and carry them from one bacterial cell to another Virulent Phages Immediately lyse and kill the host Temperate Phages Remain within the host cell for a period without killing it Prophage A phage integrated into the bacterial genome Lysogenic A bacterium harboring a quiescent phage (the bacterium itself is called a lysogen) Generalized Transduction The ability of certain phages to transduce any gene in the bacterial chromosome Cotransductants Two donor alleles that simultaneously transduce a bacterial cell; their frequency is used as a measure of closeness of the donor genes on the chromosome map Specialized Transduction The situation in which a particular phage will transduce only specific regions of the bacterial chromosome Zygotic Induction The sudden release of a lysogenic phage from an Hfr chromosome when the prophage enters the F- cell followed by the subsequent lysis of the recipient cell Attachment Site Region at which the prophage integrates Insertional Mutagenesis The situation when a mutation arises by the interruption of a gene by foreign DNA, such as from a transfenic construct or a transposable element