1.)A.)The lac operon is inducible by the presence of lactose.Loss-of-function mutations in the lacI gene, which encodes the lacrepressor (pick all that apply):

A.)slow down the isomerization of lactose into allolactose
B.)decrease the amount of permease activity in the cell in thepresence of lactose.
C.)prevent loss-of-function lacZ mutations from making the lacoperon uninducible
D.)are recessive to wild type

B.)Mutations that eliminate the lacO operator site (pick all thatapply):

A.)slow down the isomerization of lactose into allolactose
B.)decrease the amount of beta-galactosidase in the cell in thepresence of lactose
C.)prevent lacS superrepressor mutations from making the lac operonuninducible
D.)are recessive to wild type

C.)Loss-of-function mutations in the lacZ gene, which encodesbeta-galactosidase (pick all that apply):

A.)slow down the isomerization of lactose into allolactose
B.)decrease the amount of permease activity in the cell in thepresence of lactose
C.)prevent lac repressor from binding the lacO operator site
D.)prevent IPTG from inducing the lac operon

D.)You are studying the Tory operon, which encodes the TorA andTorB genes, and is normally inducible by Torose. You find amutation, m1, that causes the Tory operon to be uninducible. Youexamine the merodiploid (m1 TorA+ TorB-)/(+ ToryA- TorB+) and findthat Tor A is uninducible and TorB is inducible. You concludethat:

A.)m1 acts in cis
B.)m1 acts in trans