An operon encoding genes that are transcribed and translated continuously to provide the cell with constant intermediate levels of the protein products is said to be which of the following?

repressible

inducible

constitutive

activated

constitutive

Explanation:

Some of the operons encode for the genes whose products are continuously required by cells. The products of these genes are involved in the metabolic pathways that occur at more or less constant levels in all the cells of an organism. These genes are expressed continuously to provide a constant supply of their products.

An operon that code for such genes that are expressed at a constant level to ensure a continuous supply of their products to the cells is said to be the constitutive operon.