Answer:
Operon.
Explanation:
Operon is known as a functional unit of DNA. They also present in viruses, for example bacteriophage. In general words, operon is basically a group of genes under the control of one promoter.
In bacteria genes are often present in a cluster of the chromosomes in which they are transcribed from one promoter or RNA polymerase binding site as a single unit. Under control of single promoter this cluster of gene is known as an operon.
