Suppose that two strains of E. coli - strain a (bio- met- leu+ thr+ thi+) and strain b (bio+ met+ leu- thr- thi-) - conjugate. If the two strains are grown on minimal medium, what is the most likely genotype of their offspring?
Suppose that a researcher is looking for met- strains of E. coli. She compares two plates. One plate has colonies growing on complete media. The other plate has colonies growing on methionine-deficient media. How can the researcher determine which colonies are met-?