Answer:
Operons
Explanation:
1. Operon: is a set of genes which are transcribed under the control of an operator gene. These genes are transcribed according to the requirement in the cell under a regulatory mechanism.
2. Or, an operon is a segment of DNA containing adjacent genes including i) structural genes, ii) an operator gene, and iii) a regulatory gene, which are transcribed together.
3. Thus an operon is a functional unit of transcription and genetic regulation which is regulated in a strict manner.
4. Example of operon; i) Lac operon in E.coli.