Answer:
d. Genes that play a role in the same metabolic pathway are organized into an operon.
Explanation:
In prokaryotic organisms like bacteria, polycistronic mRNAs exist which means that each gene does not have a separate promoter of its own. In fact many genes are under the control of a single promoter. These genes being a part of same metabolic pathway are organized into an operon. For example, lac operon and tryptophan operon. In lac operon, three genes named as β-galactosidase, permease and transacetylase are expressed under a single promoter which is known as lac promoter.
In contrast to this, in eukaryotes the mRNAs are monocistronic i.e. only a single gene is controlled under a single promoter.
