bacterial genetics Flashcards
bacteria multiply by
binary fission
what are the three mechanisms bacteria acquire new DNA
transformation, transduction, and conjugation
____________is when DNA acquired from environment
transformation
____________is when DNA is acquired from bacteriphage (virus)
transduction
___________-is when DNA acquired from bacterial sex
conjugation
how many chromosomes are in the bacterial genome
1 chromosome
________are small DNA ciircles that replicate independently of the chromosome that have 1 copy or many copies per cell
plasmid
___________is the uptake of naked DNA from environment by competent cells
transformation
________-is a minor form of recombination in nature but a major form in biotechnology
transformation
in ____________usually linear DNA is released from dying cells
transformation
HR requires
several genes worth of homology or near homoloygy and recombination enzymes/factors coded by recA, B,C, D (A is absolute requirement)
______is the transfer of bacterial DNA by a bacteriophage
transduction
________is a virus that attacks bacterial cells
bacteriophage
two types of transduction
generalized and specialized
generalized transduction
phage picks up a piece of bacterial DNA-all genes have equal change of being transduced
specialized transdunction
dependent on integration of phage DNA into a bacterial chromosome at specific site, and an excision error allows bacterial DNA to be excised and packaged with phage DNA
the lytic cycle…
LYSES bacteria
the lysogenic cycle….
integrates into the bacterial genome
____________type of phage causes death of bacterial cell by lysis (lytic)
virulent
_______type of phage causes death of bacteiral cell by lysis or integration into host chromosome forming a pro-phage (lysosogeny)
temperate
lysogeny
expression of phage genes is repressed, no new phage are made, host cell survives, and phage DNA replicates as part of the host
_________leads to the production of viruses and their release upon cell lysis
lytic infection
________-type of viruses can only go into lytic cycle and can only carry out generalized transduction
virulent viruses
_____type of bacteria are those with a prophage
lysogenic
integration of the prophage is _________but can be ____________- by UV light and chemicals
stable, destablized
acquisition of bacterial properties due to prophage is called
lysogenic conversion
what types of bacteria are capable of lysogenic conversion
diptheria,, s pyogenes, and C botulinum
bacterial genes picked up as error in excision are transferred to homologous gene in another bacteria
specialized transduction
what type of genes may be transferred in generalized trandcution
any
what type of genes can be transferred in specialized transduction
only genes next to insertional site
what is the mechanisms for generalized transduction
error in assembly
what is the mechanism for specialized transduction
error of excision, requires stable insertion of the prophage
______is the transfer of genes from 1 cell to another cell by cell contact
conjugation (requires male and female bacterial cells (sex pilus)
______________are genes that promote their own transfer
conjugative plasmids
fertility plasmids contain
sex pill genes that stabilize mating bacteria genes which direct conjugal DNA transfer and other genes oriT insertion sequences
chromosomal mobilization
strains of bacteira with F plasmid integrated are Hfr (high frequency of recombination)
is cell to cell contact a requirement for transformation
no
is cell to cell contact a requirement for conjugation
yes
is cell to cell contact a requirement for tranduction
no
phage infection is involved in
transduction
competency is required for
transformation
naked DNA involved
transformation
is HR required
transformation, transduction and not for F+/F- or yes for Hfr and F-
mechanisms of antibiotic resistance
intrisnic, chromosomal mediated, and plasmid
____________cell lacking cell wall resistant to penicillin
intrisnic antiobiotic resistance
_________usually via modification of receptor for drug
chromsomal mechamsism of antibiotic resistance