Genes whose expression is turned on in response to a substance in the environment are known as
A) inducible genes.
B) repressible genes.
C) constitutive genes.
D) inducible genes and repressible genes.
E) All of these are correct.

Question

Quizplus · Accepted Answer

Inducible genes are turned on (or "induced") by a specific stimulus or substance, such as a hormone or nutrient in the environment. Repressible genes are turned off (or "repressed") by a specific stimulus or substance, such as an abundance of a certain molecule. Constitutive genes are always expressed, regardless of environmental conditions. Therefore, only choice A accurately describes genes that are turned on in response to an environmental substance.

Genes Whose Expression Is Turned on in Response to a Substance