an immune system? The complex disease of AIDS warns what happens when a person does not have a properly functioning one. This disease has baffled our best medical scientists for years. First, we would have to make some cells—a quadrillion of them (10 15). But to make just one cell would be an exercise of awesome complexity. Moreover, we would have to work on a very small scale, for the nucleus of each cell—containing the cell’s genes and chromosomes—must be less than .0004 inch in diameter. The components