Medium No of colonies Complete medium 90 complete medium + ampicillin 40 minimal
ID: 193890 • Letter: M
Question
Medium No of colonies
Complete medium 90
complete medium + ampicillin 40
minimal medium (glucose as carbon source) 36
minimal medium + ampicillin (an antibiotic) 17
minimal medium + methionine (an amino acid) 64
minimal medium + arginine (an amino acid) 54
minimal medium + methionine + ampicillin 30
minimal medium + arginine + ampicillin 24
The table above summarizes the results of a replica-plating experiment where a mixture of 90 E. coli strains of different genotypes were tested for their ability to growth on a variety of media. Based on the data presented in the table above, how many colonies are amp(R) met(-) arg(-)?
*Please explain how you found the answer
Explanation / Answer
How many colonies are amp(R) met(-) arg(-)?
Amp(R) 40 (Resistance to Amp, Since they could grow in additinal ampicillin).
Met(-) (90-30) = 60 (Met sensitive stains, Since they could not grow in Met additinal medium).
Arg(-) (90-24) = 66 (Arg sensitive stains, Since they could not grow in Arg additinal medium).