Question

(3 pts) There is a new mutation in the Lac/gene, called IN, that introduces a missense mutation in the DNA binding domain of the protein. IN can not bind to the operator. Predict the outcome of the following lac operon genotype for the expression of functional lac enzymes in the different conditions indicated. (Note: + = wildtype, - = no functional protein made.) IN O+P+ Z-Y+ - lactose + lactose b-gal (Z) Permease (Y) b-gal (Z) Permease (Y) + + + + i + + + i i I i + E) + + +

Answer 1

Answer=A

Explanation-

Lac IN has mutation,it can't bind to operator so Permease (Y) gives expression in both types of condition (lactose absent and lactose present).

b-gal(Z) gene makes no functional protein in both types of condition (Lactose absent and lactose present) so it gives no expression in both types of condition (lactose absent and lactose present).

So option A is correct answer rest all the options are incorrect.

Option B,C and E are incorrect because b-gal(Z) gives expression but in given condition b-gal(Z) gene is mutatet so b-gal(Z) gives no expression.

Option D are incorrect because it show no expression but Permease show expression in both condition so this is incorrect.