Just as it is hard to describe a spiral staircase without using your hands, so it is difficult to understand the double helix without a three-dimensional model. This one is easy to glue together and makes a fine mobile. There are also other models which shed light on the nucleotides, viruses and protein synthesis. Included also is a minibook which links together the models with lots of interesting information about the role that DNA plays in genetics and in the evolution of life on our planet into all the marvellous diversity we can see today.