Answer:
E. None of A-D are false; all are true statements.
Step-by-step explanation:
A. The operator of an operon serves as a regulatory/control element.
An operon, is a genetic regulatory system found in bacteria and their viruses, in which genes code for functionally related proteins and are clustered along the DNA. A promoter is controlled by various regulatory elements that respond to environmental cues.
B. They possess a single promoter.
Operons consists of a group of structural genes and these genes are located contiguously on a stretch of DNA and are under the control of one promoter (a short segment of DNA to which the RNA polymerase binds to initiate transcription).
C. The structural genes of an operon will be components of different metabolic pathways.
A typical operon, consists of a group of structural genes that code for enzymes involved in a metabolic pathway, such as biosynthesis of an amino acid.
D. The transcript of an operon will be an RNA copy of all the structural genes contained in a single polynucleotide sequence.
A single unit of messenger RNA is transcribed from the operon and is subsequently translated into separate proteins.