Question

In the lac operon, 1 codes for the repressor protein, P is the promoter which is necessary for binding RNA polymerase, O is the operator, and Z codes for the B-galactosidase. Assuming (+) denotes the wild type for a particular locus, (-) denotes a lack of a particular gene product or function, O^c is a constitutive operator, and I^s is a super repressor. Use a "+++" sign to indicate that significant quantities of functional B-galactosidase are present, a '+' sign to indicate that there is little quantities of functional B-galactosidase present, or use a sign to indicate that B-galactosidase is not present in appreciable quantities for each of the following media.

Answer 1

	No lactose + glucose	+ lactose + glucose	No lactose No glucose	+ lactose No glucose
1	+++	+++	+++	+++
2	+++	+++	+++	+++
3	-	+	-	+++
4	-	+	-	+++
5	-	+	-	+++
6	-	+	-	+++
7	-	+	-	+++
8	+++	+++	+++	+++

There is two genotypes one is strain and the other is Hfr strain (the oblique one). if strain does not have the gene, it can take the gene from Hfr strain (if that have). Mutation in operator cannot control the gene production whether lactose present or absent. Mutation in repressor cannot bind to lactose if it have, and if it cannot bind the beta-galactosidase production will suppress if operator is present.