Fill in the blanks with the appropriate words (ON, OFF, DOMINANT CO-DOMINANT or RECESSIVE).

a. Indicate whether transcription of the lac operon would be ON or OFF under the conditions listed below, for the following mutant strains of E. coli. In addition, indicate whether the mutant phenotype (pattern of transcription) would be DOMINANT, CO-DOMINANT or RECESSIVE to wild type.

Lactose only carbon source Glucose only carbon source Dom./Rec.

lac I deletion

lacO deletion

b. Indicate whether transcription initiation of the trp operon would be ON or OFF under the conditions listed below, for the following mutant strains of E. coli. In addition, indicate whether the mutant phenotype (pattern of transcription) would be DOMINANT, CO-DOMINANT or RECESSIVE to wild type.

Tryptophan Present Tryptophan Absent Dom./Rec.

trpR deletion

trp O deletion

PLEASE EXPLAIN