The labels for ten bacterial strains were mixed up and now you do not know the identity of each strain. You know all strains are
auxotrophs and each one has a single, unique mutation. You set up pairwise crosses between bacterial strains and select for exconjugants by plating on MM. Use the information below to determine F-, F+, and Hfr strains. (- means no colonies grow on MM after conjugation, + means few colonies, +++ means many colonies) Please Explain why F- strains: A1, A2, B5 F+ strains: A3, A4, B3, B4 and Hfr strains: B1, B2, A5 B1B2B3B4B5 A1++++++++- A2++++++++- A3----+ A4----+ A5----+++ F- strains: ______________ F+ strains: _________________ Hfr strains:
As auxotrophs are mutants organism which requires particular additional nutrients which normal strains can not,
Hfr A high-frequency recombination cell (Hfr cell) (also called an Hfr strain) is a bacterium with a conjugative plasmid (for example, the F-factor) integrated into its chromosomal DNA
F+have fertity factor and are considered to be inheritable( male) while female have non and do not make pill for conjugation
