Final answer:
A biosynthetic pathway's operon would, in most cases, be a repressible operon that is suppressed when the end product accumulates within the cell. If genes are continuously expressed at a constant level, the operon is known as a constitutive operon.
Step-by-step explanation:
An operon of genes encoding enzymes in a biosynthetic pathway is likely to be a repressible operon. Repressible operons typically contain genes that are required for a biosynthetic pathway and their expression is repressed when the product of the pathway accumulates in the cell. In contrast, inducible operons contain genes encoding enzymes in a pathway involved in the metabolism of a specific substrate and their expression is induced only in the presence of the substrate.
An operon of genes encoding enzymes in a biosynthetic pathway is likely to be a repressible operon. Repressible operons, such as the tryptophan (trp) operon, typically contain genes that are needed for a biosynthetic pathway to synthesize an end product that the cell requires. When the end product begins to accumulate, indicating there is enough of it within the cell, the operon is repressed to prevent the synthesis of enzymes that are no longer needed at high levels.
However, if a student asks about an operon encoding genes that are transcribed and translated continuously at moderate levels, regardless of the concentration of the end product, it would be described as a constitutive operon. Constitutive operons are always active, and their gene expression is unregulated, meaning their enzymes are constantly produced by the cell.