What makes gingers ginger?

Doctors Adam Rutherford and Hannah Fry set out to solve the following perplexing cases sent in by listeners:

The Scarlet Mark Sheena Cruickshank in Manchester asks, "My eldest son is ginger but I am blonde and my husband brunette so we are constantly asked where the red came from. Further, people do say the 'ginger gene' is dying out, but how good is that maths or is it just anecdotal?"

Our science sleuths set out to discover what makes gingers ginger with a tale of fancy mice, Tudor queens and ginger beards. Featuring historian and author Kate Williams and Jonathan Rees from the University of Edinburgh, who discovered the ginger gene.

The Hairy Hominid "How does leg hair know it has been cut? It does not seem to grow continuously but if you shave it, it somehow knows to grow back," asks Hannah Monteith from Edinburgh in Scotland.

Hannah Fry consults dermatologist Dr Susan Holmes, from the Hair Clinic at Southern General Hospital in Glasgow, to discover why the hairs on your legs do not grow as long as the hairs on your head.

Adam attempts to have a serious discussion about the evolutionary purpose of pubic hair with anatomist and broadcaster Prof Alice Roberts.

If you have a scientific mystery for the team to investigate, please email curiouscases@bbc.co.uk

Producer: Michelle Martin

Image: A woman with splendid hair, lying on grass, Credit: Thinkstock