Biological Circuits Are Different From Electronic Circuits

In an electronic circuit, there is noise in the flow of electrons along a wire. It's just that we've designed electronic circuits so that magnitude of that noise virtually never affects the behavior of the circuit. Life does not seem to operate in that regime. Inside the cell, the expression of a gene can and does fluctuate. And those fluctuations are random. They're intrinsically random and they're in a way beyond the control of the cell.