Our genes can tell us so much about us, from why we look the way we look, think the way we think, even what kind of diseases we might be likely to suffer from. But our genes aren't the whole story. There are other, complex and intriguing systems within every cell in our bodies which control which of our tens-of-thousands of genes are switched on, or off, in different parts of the body, and under different circumstances.

Welcome to the fascinating world of 'epigenetics', which our guest, the molecular geneticist Anne Ferguson-Smith, describes as 'genetics with knobs on'.

Anne, now Arthur Balfour Professor of Genetics and Pro-Vice Chancellor for Research at the University of Cambridge, tells Jim about her life and work. She's spent her professional life at the cutting edge: from a degree in a brand new field of Molecular Biology, to post-grad working on brand new genetic structures, through to a lifetime of discoveries and breakthroughs which have changed our understanding of the genome.

Yet she wasn't always destined to be a scientist. She says she was a 'bad student' for a lot of her early life, and believes that embracing failure is an essential part of being a working scientist.