Which of the Following is Not True of a Genetically

Question

Which of the following is not true of a genetically encoded toggle switch?
A) It allows expression of one of two alternative operons.
B) It is bistable.
C) It is controlled by small molecules.
D) Transient exposure to the control molecule is sufficient for stable activation.
E) The native lac operonconstitutes an example of a toggle switch.

Accepted Answer

The native lac operon does not constitute an example of a genetically encoded toggle switch. A toggle switch involves a system where two genes repress each other, allowing the system to stably exist in one of two states. The lac operon, however, is a regulatory mechanism that responds to the presence or absence of lactose and is not a bistable switch that maintains one of two stable states without continuous input.