Question

State the arrangement of different genes that in bacteria is referred to as operon.

Answer 1

The arrangement of different genes in bacteria is

(a) Structural gene: A structural gene is a gene that codes for an RNA or protein product other than a regulatory factor.

(b) Operator gene: Operator genes contain the code necessary to begin the process of transcribing the DNA message of one or more structural genes into mRNA.

(c)Promoter gene: promoter is a region of DNA that initiates transcription of a particular gene. Promoters are located near the transcription start sites of genes, on the same strand and upstream on the DNA (towards the 3' region of the antisense strand).

(d) Inhibitory/regulatory gene: A gene which inhibits the expression of an active allele situated at a different locus is called an inhibitory gene. Thus, in inhibitory gene action, one dominant inhibitory gene prevents the expression of another dominant gene.