bacterial genetics Flashcards
are bacteria diploid?
no, haploid
what is medium that wild-type bacteria can grow on?
minimal medium (carbon source, salt, minrals)
what can wild-type cells synthesise from minial medium?
vitamins, amino acids, carbs + nuceotides
what prevents growth on a minimal medium ?
a mutation that effects biosynthetic pathway
what does complete medium contain?
all amino acids, vitamins, nucloetides
where will cells carrying a mutation inactivating a biosynthetic plathway grow?
on a complete medium but not on a minimal medium
where will bacteria grow carrying a gene involved in a specific biosynthetic pathway?
on a minimal medium containting biosynthethetic priduct
what is auxotroph?
bactera carrying a mutation that cannot syntheise essential nutirents
what are phototrophs?
bacterial strains that are wild type for a particular niosynthetic pathway
what happens to gene transfer in davis-U tube?
genetic transfer cannot occur as in tube there is no direct contact between auxotroph cells
what is fertility factor?
(F+) circular DNA molecule taht allows carriers to conjugate wih F- recipient cells
what happens to F+ during conjugation?
it is replicated and copy is transferref through F pilus to F- recipient
how can high frequency combination strains cause host genes into F-?
F plasmid recombines with host DNA. INtegrated F can leave chromosome and carry host genes with it . which can then be copied and transferred into F- during conjugation
how can trancription of some genes be regulated?
by a sequence next to promoter region that a repressor can bind to , to prevent the trans[rt of RNA polymerase. . when repressor dissociates, rna polymerase can pass- induces transcription
what can enzymes coded by e.coli do?
break down lactose into glucose and galactose
