Gene
Regulation
Jacob and Monod (1961) proposed the operon model to explain the control of gene activity. It was assumed that there are three kinds of genes, structural genes, operator genes and regulator genes.
Structural genes are those that produce mRNA. Operator genes control structural genes by acting as switches in controlling mRNA synthesis by the latter.
These different types of genes together constitute the operon. Regulator genes produce substances (repressors) which block the operator genes, so that mRNA synthesis by structural genes is prevented.
