Question

See Section 18.2 (Page 371) . View Available Hint(s) In lacI —mutant cells, when there are high levels of glucose present but no lactose, how much β-galactosidase will be produced? See Section 18.2 (Page 371) . A low amount A great deal It depends on what other sugars are present in the growth medium. Essentially none

Answer 1

Answer:

Option D, Essentially none

Explanation:

The essential condition for lac operon to express its subsequent proteins i.e laz A, lacZ and lacY are as follows –  

a) Absence of glucose

b) Presence of Lactose.  

In fact absence of glucose is must. In case when lactose is absent and glucose is present then the lac z sub-protein whose product is  β-galactosidase is not expressed. In fact in lac z breaks down lactose into glucose and galactose in absence of glucose.  

Hence, option D is correct