Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 1

Laboring with lac. Most of what we know about the lac operon of E. coli has come from genetic analysis of various mutants. In the following list are the genotypes of seven strains of E. coli. For each strain, indicate whether the Z gene product will be expressed in the presence of lactose and whether it will be expressed in the absence of lactose. Explain your reasoning in each case.
(a)

(b)

(c)

(d)

(e)

(f)

(g)Same as part a, but with glucose present