For regulatory information I 2 , in fact, every protein molecule is not produced independently. A bacterium does not once synthesize only one protein molecule, but a batch of protein molecules. Only the first protein molecule in the batch is independent, the possibility is × kinds of protein. The other following protein molecules are not independent. The possibilities follow the previous protein, which can only be 1. If a bacterium synthesizes 100 protein molecules at a time, I 2 is: