chapter 3 bacterial sex genetics Flashcards
temperate phage
bacteriophage that undergoes adsortpion and penetration but the DNA from the virus becomes incorporated into the bacterial chromosome
integrated temperate phage genome is called a
prophage
also lysogenic
lysogenic immunity
ability of an integrated bacteriophage to block subsequent infection by a similar phage
first one to infect produces a repressor protein
corynebacterium diphterias exotoxin is obtained by what
lysogenic conversion
the ___ phage gets inserted into E coli and in specialized transuction what genes are accidentally spliced out with the phage DNA
lambda phage
biotin and galactose
transformation
dna fragments from one bacterium released during cell lysis bind to cell wall of another bacterium
-recipient must be competent
generalized transduction: virulent or temperate phages
virulent
generalized transduction process
after the phage penetrates host bacteria, phage is translated into capsids and enzymes
bacterial DNA reperessed and destroyed, sometimes pieces of bacterial DNA are left intact
- can be packaged into phage capsid head
- following lysis and release of phage this bacterial DNA can then be injected into antoher bacteria
- this bacteria survives since no phage DNA just other bacteria
specialized transduction occurs with ___ phages
temperate
temperate phage process
when prophage is ready to become active, it is spliced out of bacterial DNA
-sometimes part of bacterial DNA can be spliced out too
for conjugation to occur one bacterium must have a ___
F plasmid (F+)
self transmissible plasmd has a gene that encodes enzymes and proteins that form the ____ which is used as a bridge to transfer DNA
sex pilus
if the F plasmid becomes integrated into the neighboring bacterial chromosome then the bacterial cell is then called
Hfr cell
DNA transfer with Hfr cell (2 mech)
1) entire bacterial chrom including integrated F plasmid transfers from Hfr cell to recipient cell
Integrated F plasmid in the Hfr cell may be exiced at different site from that of integgration
-now F plasmid also has segment of chromosomal DNA
= Fâ plasmid
pieces of DNA that can insert themselves into a donor chromosome WITHOUT having DNA homology
transposons
