On Start the Week Andrew Marr talks to Peter Wothers about modern day alchemy, as we enter a new era of chemistry. In the past some scientists dismissed the vast majority of the human genome as 'junk DNA', Ewan Birney argues for renaming it 'enigmatic DNA'. And curiosity gets the better of Sanjeev Gupta as he explores the terrain on Mars. But science doesn't have all the answers as Helen Bynum charts the history of tuberculosis, from the medieval period to the present day, and looks at how this killer disease continues to spread and evolve. Producer: Katy Hickman.

On Start the Week Andrew Marr explores what it means to be Scottish. The streets and history of Edinburgh come alive in Ian Rankin's crime novels, while the Glaswegian writer and artist Alasdair Gray marries elements of realism, fantasy and science fiction in his work. With a long history of Scottish emigration, T M Devine looks at the impact on the nation left behind. And the theatre critic of The Scotsman, Joyce McMillan, believes that despite the coming Referendum on Independence, it's the arts and not politics that define Scottish-ness.Producer: Katy Hickman.Image © Alasdair Gray, A Life in Pictures, Canongate Books.

On Start the Week Andrew Marr discusses the prospect of an Iran with nuclear weapons. David Patrikarakos points to the failure to understand how far Iran's nuclear strategy is linked to its recent history and sense of identity. Geoffrey Robertson QC argues that the production of atomic bombs should be made an international crime against humanity, whereas Baroness Shirley Williams believes that politics still has a role to play in disarmament around the world. But Douglas Murray dismisses the idea that political negotiation or the law will work, and believes force may be the only answer.Producer: Katy Hickman.

On Start the Week Andrew Marr looks at Germany's role in Europe. Katinka Barysch argues that despite the crisis, support for EU integration still dominates, and that unlike Britain, the ability to compromise is seen as a skill, not a weakness. Two British MPs, from left and right, Gisela Stuart and Douglas Carswell, remain sceptical about the EU, but German-born Stuart understands her birth country's emotional connection to it. Carswell argues that the digital revolution calls for smaller, not larger governments, and Karen Leeder believes that despite Germany's belief in the European project it still has not laid to rest the ghosts of unification. Producer: Katy Hickman.

On Start the Week, Andrew Marr explores how Britain trains the artists and designers of the future. Christopher Frayling and Sarah Teasley celebrate the 175th anniversary of the Royal College of Art, the world's oldest art and design school. But one of its former teachers, the industrial designer Ron Arad argues for a broader arts education which doesn't split sculpture from painting, architecture from design. And the artist Antony Gormley redefines the limits of sculpture and building. Producer: Edwina Pitman

On Start the Week Andrew Marr talks to the award-winning director Kevin Macdonald whose films often focus on real events or people, from Touching the Void, to Marley. The filmmaker Roger Graef discusses the ethical issues in documenting real life. And the Indian writer Aman Sethi explores the margins of society with his study of the world of itinerant labourers in a Delhi market. Producer: Katy Hickman.

Start the Week is at BBC Radio 3's Free Thinking Festival in Gateshead to debate whether the world is becoming a more divided place. Andrew Marr discusses the state of politics with the former President of Ireland Mary Robinson and the writer-turned-politician Michael Ignatieff, while the Israeli author Amos Oz asks whether entrenched ideas have increasingly polarised debate. Producer: Katy Hickman.

On Start the Week the journalist Ian Cobain reveals how torture has been systematically used by the British from WWII to the War on Terror, via Kenya and Northern Ireland. David Anderson QC reviews the risks posed by terrorism in the UK. Extraordinary rendition and the language of concealment form the heart of Clare Bayley's new play, and there are more secrets uncovered by the criminal barrister-turned-crime writer, MR Hall. Producer: Katy Hickman.

On Start the Week Andrew Marr looks at the legacy of modernism. Kevin Jackson returns to 1922, the year he argues changed the literary world with publications of Joyce's Ulysses and TS Eliot's The Waste Land. And Ali Smith reveals how her writing today melds different forms to explore style, love, death and the art of writing. But Will Gompertz and the composer Julian Anderson argue that art and music respectively embraced modernism earlier and more profoundly than the world of literature. Producer: Katy Hickman.

On Start the Week Andrew Marr talks to two American authors, Richard Ford and Lionel Shriver about the state of the US. In the run-up to the Presidential elections, the journalist Edward Luce argues that the country's politics are broken, and America is facing the spectre of decline. But the chair of Republicans Abroad UK, Thomas Grant, disputes such a negative assessment. Producer - Katy Hickman.