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a medium that contains only the nutrients required by prototrophip bacteria is termed minimal medium TERM 2 mutant strains called () lack one or more enzymes necessary for metabolizing nutrients or synthesizing essential molecules DEFINITION 2 auxotrophs (will grow only on medium supplemented with one or more nutrients) TERM 3 () medium contains all the substances such as amino acids leucine, required by bacteria for growth and reproduction DEFINITION 3 complete TERM 4 cultures of bacteria are often grown in () that contain sterile liquid medium DEFINITION 4 test tubes (also grown in petri plates) TERM 5 advantage of bacterial growth by petri dish DEFINITION 5 allows one to isolate and count bacteria, which individually are too small to see without a microscope
in a process called () a dilute solution of bacteria is spread over the surface of an agar- filled petri plate plating TERM 7 (plating) as each bacterium grows and divides, it gives rise to a visible clump of genetically identical cells called DEFINITION 7 a colony TERM 8 genetically pure strains of bacteria can be isolated by DEFINITION 8 collecting bacteria from a single colony and transferring them to a new test tube or petri plate TERM 9 (bacteria) it is often easier to study () that affect the appearance of the colony or can be detected by simple chemical tests DEFINITION 9 phenotypes TERM 10 () are commonly studied phenotypes DEFINITION 10 auxotrophs
some plasmids promote () between bacteria; others contain genes that () other bacteria mating, kill TERM 17 most plasmids are () and several () bp in length DEFINITION 17 circular, thousands (plasmids consisting of several hundred thousand bp also have been found.) TERM 18 a plasmid replicates (dependently/independently) of the bacterial chromosome DEFINITION 18 independently (possesses its own origin of replication) TERM 19 (plasmid) replication proceeds from the origin in one or two directions until () DEFINITION 19 the entire plasmid is copied TERM 20 () are plasmids that are capable of freely replicating and able to integrate into the bacterial chromosomes DEFINITION 20 episomes
the () of E. coli is an episome that controls mating and gene exchange between E. coli cells F (fertility) factor TERM 22 () takes place when genetic material passes directly from one bacterium to another DEFINITION 22 conjugation TERM 23 in (), DNA is transferred only from donor to recipient, with no reciprocal exchange of genetic material DEFINITION 23 conjugation TERM 24 () takes place when bacterium takes up DNA from the medium in which it is growing DEFINITION 24 transformation TERM 25 after transformation, () may take place between the introduced genes and those of the bacterial chromosome DEFINITION 25 recombination
(F factor) transfer of genetic material has a defined () direction TERM 32 if the entire F factor is transferred to the recipient F- cell, that cell becomes an () cell DEFINITION 32 F+ TERM 33 in () strains, the F factor is integrated into the bacterial chromosome DEFINITION 33 Hfr (high frequency) TERM 34 Hfr cells behave as () cells, forming () and undergoing conjugation with () cells DEFINITION 34 F+, sex pili, F- TERM 35 (between Hfr and F-) integrated F factor is (), and the end of the nicked strand moves into the () cell DEFINITION 35 nicked, F-
because in an Hfr cell the F factor has been integrated into the bacterial chromosome, the chromosome follows it into the recipient cell TERM 37 how much of the bacterial chromosome is transferred depends on the DEFINITION 37 length of time that the two cells remain in conjugation TERM 38 in a mating of Hfr x F-, the F- cell (becomes/never becomes) F+ or Hfr DEFINITION 38 never becomes (because the F factor is nicked in the middle in the initiation of strand transfer, placing part of F at the beginning and part at the end of the strand to be transferred.) TERM 39 To become F+ of Hfr, the recipient cell must recieve DEFINITION 39 the entire F factor (rare because most conjugating cells break apart before the entire chromosome has been transferred) TERM 40 The F plasmid in F+ cells integrates into the bacterial chromosome, causing F+ cell to become () DEFINITION 40 Hfr (frequency only about 1/10,000)
competence is influenced by 3 things growth stage, the concentration of available DNA, and the composition of the medium. TERM 47 the DNA that a competent cell takes up (has to be/need not be) bacterial DEFINITION 47 need not be (virtually any type of DNA can be taken up by competent cells under the appropriate conditions) TERM 48 as a DNA fragment enters the cell in the course of transformation, one of the strands is (), whereas the other strand () DEFINITION 48 hydrolyzed, moves across the membrane and may pair with a homologous region and become integrated into the bacterial chromosome TERM 49 ways in which to speed up the process of transformation DEFINITION 49
- treatment with calcium chloride, heat shock, or an electrical field makes bacterial membranes more porous and permeable to DNA, 2. high concentrations of DNA TERM 50 transformation, like conjugation, is used to () bacterial genes DEFINITION 50 map
cells that receive genetic material through transformation are called transformants TERM 52 genes can be mapped by observing the rate at which two or more genes are () in transformation DEFINITION 52 cotransformed TERM 53 when DNA is fragmented during isolation, genes that are physically close on the chromosome are more likely to DEFINITION 53 be present on the same DNA fragment and transferred together TERM 54 the () of cotransformation can be used to map bacterial genes DEFINITION 54 frequency TERM 55 if genes a and b are frequently contransformed and genes b and c are frequently cotransformed, but a and c are rarely transformed then.... DEFINITION 55 b must be between a and c; gene order abc
(temperate phage) the lysogenic cycle begins like the () but inside the cell, the phage DNA integrates into chromosome where it remains as an () inactive prophage TERM 62 (temperate phage) the prophage is replicated along with the () and is passed when the bacterium () DEFINITION 62 bacterial DNA, divides TERM 63 after several rounds of phage reproduction, a clear patch of lysed cells, or () appears on the plate DEFINITION 63 plaque TERM 64 each plaque represents a () that multiplied and lysed many cells DEFINITION 64 single phage TERM 65 in () transduction, any gene may be transferred DEFINITION 65 generalized
in () transduction, only a few genes are transferred specialized TERM 67 DNA gets packaged into a phage coat; phage particles called DEFINITION 67 transducing phages TERM 68 the transducing phage infects a new cell, releasing the bacterial DNA, and the introduced genes may then become integrated into the bacterial chromosome by DEFINITION 68 a double crossover TERM 69 transduction requires 3 things DEFINITION 69
- that the phage degrade the bacterial chromosome 2. that the process of packaging DNA into the phage protein 3. that the bacterial genes transferred by the virus recombine with the chromosome in the recipient cell TERM 70 (all/not all) phages are capable of transduction DEFINITION 70 not all
