We have two metres of DNA inside each of our cells. Genes are collections: an ensemble of genomic sequences made of DNA which have a coherent function and lie in a locus. The genome is the code that allows cells to divide, multiply and specialise. You will learn more about rare diseases and their genetic origin and neurodegenerative disease and the kinds of processes that might happen when a brain degenerates. You will also discover the tight connection between genetics and epigenetics to remember that more than DNA is involved.