Question

The following shows the genotype of a partial diploid bacterial cell - where one chromosomal region containing the lac operon in E, coli is given, and the other fragment is from a plasmid carrying another lac operon from another source. The two are separated by a slash (/). The possible answers indicate with a"+" or awhether beta-galactosidase would be expected to be produced at induced levels under two circumstances: 1) first in the absence of lactose and 2) second in the presence of lactose. (Assume that glucose is not present in the medium.) KEY: l+ = wild-type repressor I- = mutant repressor (unable to bind to the operator) Is = mutant repressor (insensitive to lactose) O+ = wild-type operator Oc = constitutive operator (insensitive to repressor) Genotype D: I- 0+ Z+/F I- 0+ Z+ Genotype E: I + 0+ Z+/F I + 0+ Z+ Genotype F: I- Oc Z-/F I- Oc Z- Possible Answers: (+, +) (-, -)) (+, -)) (-, +) Cannot Tell

Answer 1