 So Watson and Crick having determined the structure of the DNA, that's amazing in the sense that it's a large biological macromolecule that we now know the structure of, which is certainly nice per se, and it is a beautiful molecule, isn't it? But DNA itself is more than a molecule. This is also storing information, right? And to us, that's obvious in hindsight, but it wasn't so obvious in the first part of the 20th century. And one of the important things with this model is that the way the bases are stacked here, it also provides a mechanism for how this information is stored. So the first part that Watson and Crick note in their paper is that the base pairing, if A always binds to T, that means that if I now take the spiral and tear it apart, well, this A here would be bound to a T here. But it doesn't matter, because the only thing that would bind efficiently to that A is another T, and the only thing that would bind efficiently to this T is another A. So I have some sort of redundancy here, and this redundancy means that I also have a copying mechanism, right? If I split the helix, each part can form a new helix with exactly the same information. That's kind of similar to computers, that in computers you use electricity, you use switches that use zeros or ones to store information. It's not exactly the same here, so in each position here I have one out of four bases, A, G, C, or T. That actually corresponds to two bits of information. So it would be 0, 0, 0, 1, 1, 0, or 1, 1. So that means that each position here stores the equivalent information of two bits. The entire human genome would contain something like three billion base pairs, and that codes for some 20,000 proteins in terms of a human. And that means that we can now do some fairly complex things. We can store the information if I happen to damage my DNA, so let's say one of these bases disappear. Well, if we repair that quickly enough, I'm not going to lose any information because I have the complementarity in the other strand. And this base pair complementarity is also a key discovery by Watson and Crick that it's a beautiful way of storing information stably under a long time.