Practice Questions

TLS Online TPP Program

#Question id: 5761

E. coli cells were spread on an agar plate, producing 1000 colonies. The colonies are replica plated on two agar plates containing the antibiotic kanamycin and one agar plate without antibiotics. All of the colonies are able to grow on the agar plate without antibiotic but only 4 colonies are able to grow on each of the agar plates containing kanamycin. You notice that the four colonies that grew on each of the kanamycin containing plates are in the exact same position. This demonstrates

#XL - S Microbiology

how to screen for environmental mutagens
that mutations occur in prokaryotes as well as in eukaryotes
that in some cases mutations are caused by the selective agent itself
a direct correlation between the amount of the selective agent used and the number of resistant mutants (one-hit relationship)