Cells work differently. DNA plays at least four roles:<p>* a cell can copy DNA
* a cell can transcribe a segment of DNA to make RNA which mainly goes on to make proteins but some of that RNA does different things
* a protein can stick to a particular part of a DNA molecule
* a particular part of the DNA molecule can effect the way the DNA molecule folds which affects all three processes above<p>A cell can implement a latch like this.<p>When Gene A is expressed it makes Protein A'. Protein A' sticks to Gene B and suppresses the expression of Gene B. If Gene B were not suppressed it would make protein B' which would stick to Gene A and suppress the expression of Gene A.<p>Suppose Protein C came along that also suppresses Gene A, sooner or later the A' protein falls off B and then B gets expressed, it makes B' that inhibits A.<p>So either A or B is expressed but not both, it can be flipped by an outside influence, so a cell can remember things this way. (In fact this is how nerve cells encode memories in your brain.)<p>Cells process information this way, enough to build more cells, but it is a different architecture than a microchip with registers and addresses buses and such.
There are so-called neuromorphic chips from Intel and other companies that are intentionally trying to mimic biological brains as much as possible, but they are in the research stage right now and are not widely used yet.