All of the following are part of an operon except
- an operator
- structural genes
- an enhancer
- a promoter
Answer
(3) an enhancer
Solution
As per NCERT, an operon (e.g., the lac operon) consists of the regulator gene, promoter, operator and structural genes (z, y and a), regulated together as a unit in prokaryotes.
Enhancers are regulatory DNA sequences of eukaryotic genes, and are not a part of an operon.
Answer: (3)