Auxotrophic Mutations Have Been Extremely Useful to Study a Number

Essay

Auxotrophic mutations have been extremely useful to study a number of processes in E.coli.
a)Briefly define the term "auxotrophic."
b)Suppose you were given two unlabeled tubes,one that contains a methionine auxotroph and the other that contains a leucine auxotroph.Design an experiment to determine which auxotroph is found in each tube.