An adult organism is not a static being but continues to change and develop, until the developmental processes are brought to an end by death. The word ‘ageing’ describes the developmental changes that lead, over time, to the deterioration of the mature organism. Ageing is a complex process which involves interactions between a number of biochemical mechanisms. The effects of these act at the molecular, cell, tissue and whole   organism levels. (With thanks to our sponsor 'Curriculum Press' for providing content for this podcast)