Answer:
b) Operons for coordinated gene expression
Explanation:
Operon refers to a unit of genetic function and is mainly found in bacteria and phages. An operon consists of a promoter, an operator, and a coordinately regulated cluster of structural genes. The genes of an operon code for proteins or enzymes that mostly function in a common pathway. It allows a single promoter and operator or any other regulatory sequence to regulate the expression of functionally related genes.
For instance, lac operon consists of three structural genes that code for the enzymes involved in the catabolism of lactose sugar. The operon is expressed only when lactose is available in the medium. This pattern of gene regulation is not found in eukaryotes.
