In the medium where E. coli was growing, lactose was added, which induced the lac operon. Then, why does lac operon shut down some time after addition of lactose in the medium?
1. They have several thousand genes.
2. The information is coded in the linear sequence in DNA.
3. The information in eukaryotic DNA for assembling a protein is not continuous but split.
4. Only exons code the mRNAs and introns do not code.
5. The gene expression is regulated by changing environment in a cell.