In the latest episode of the science series, Liz looks at the controversial science of genetically modified crops in Hawaii. Dallas tries to remedy Jem's dust allergy by making him eat worms. And Dr Yan tries to shatter a glass by playing the violin. The programme is co-produced with the Open University. For more ways to put science to the test, go to www.bbc.co.uk/bang and follow the links to The Open University.