Synthetic XNA: Acts a Lot Like DNA

From Not Exactly Rocket Science:

Out of all the possible molecules in the world, just two form the basis of life's grand variety: DNA and RNA. They alone can store and pass on genetic information. Within their repetitive twists, these polymers encode the stuff of every whale, ant, flower, tree and bacterium. But even though DNA and RNA play these roles exclusively, they're not the only molecules that can. Vitor Pinheiro from the M