. Regulation of gene expression We have previously established how DNA is organized into genes, how genes store genetic information, and how this information is expressed. We now consider the most fundamental issues in molecular genetics. How is genetic expression regulated?
Evidence in support of the idea that genes can be turned on and off is very XII Std Biology-Zoology Chapter- XII Std Biology-Zoology Chapter- Molecular Genetics of all the required enzymes needed for lactose metabolism ( Fig. . ). This regulation of lac operon by the repressor is an example of negative control of transcription initiation.
Lac operon is also under the control of positive regulation as well.