As far as I can tell, having iris scans, fingerprints and, yes, your whole DNA, can only prove that you and the card go together. Whether that helps to prove your ID or not is quite a different issue, in exactly the same way that having a photo in a passport does not prove the passport is genuine. The only way to prove your ID is to link to a central database and check the information from there, rather than the information on the card. And to do that, all you need is a reference number. So why the insistance on smart cards? [Keeping the central database accurate and protected is a big issue in its own right.]

There is, at least in principle, a way to make a $5 bill unforgeable - you simply have to make any method of forging it cost $6. That does not apply to ID cards or passports, which have no upper limit to their value. Using 'smart cards' increases the cost of forgery, but will actually make the value of the forgery greater.