Genes as a circuit.
There are something like 20,000 genes in the human body that directly code for proteins, so let's put that into a model you might be more familiar with. Let's imagine the genome is a circuit board and there are 20,000 components: transistors, resistors and capacitors... Maybe there's even a few memristors in there too. Now that 20,000 figure is only about 1.5% of what's going on. The other 98.5% codes for things that regulate and alter the function of the components. So we'll say that these are the wires connecting all the components together in weird and convoluted ways. Each component can be connected to itself, to one, several, or even all of the other ones, as many times as it likes. Now your job is to work out what the circuit board does and how it works, and your only tool to do this is a machete. Welcome to the wonderful world of genetics.