Various techniques have been developed to isolate strains of bacteria carrying a particular mutation.One of them is,bacteria containing wild-type cells and cells of a desired mutant are grown on a medium lacking the nutrient for which the desired mutants are auxotrophic but containing an antibiotic that only kills growing cells.In this environment,
A)both wild-type and mutant cells are killed.
B)both wild-type and mutant cells survive.
C)wild-type cells survive; mutant cells die.
D)wild-type cells die; mutant cells survive.
E)only double mutants survive.

Question

Quizplus · Accepted Answer

The medium lacks the nutrient required by the desired mutant cells (which are auxotrophic) and contains an antibiotic that only kills growing cells. Therefore, cells that are not able to grow (i.e., the desired mutants) will survive while the wild-type cells, which are able to grow due to the presence of the required nutrient, will die in the presence of the antibiotic. Thus, the only cells that will survive in this environment are the mutant cells.

Various Techniques Have Been Developed to Isolate Strains of Bacteria