Both in Britain and America, huge publicity has been given to stem cells, particularly embryonic stem cells, and the potential they offer. Of course, the study of stem cells is one of the most exciting areas in biology, but I think it is unlikely that embryonic stem cells are likely to be useful in healthcare for a long time.

I went to school with butterflies of fear every day for years - from primary school onwards - not just worried about being bullied by classmates, but by teachers.

Over the past 20 years, I have presented many science programmes on BBC1. But none is, I think, more socially important, or of more human interest, than this ongoing series of 'Child of Our Time.'

A young woman in her teens has about 300,000 eggs in her ovaries. By the time she is menopausal, none are left.

Religion has endured since the dawn of human consciousness precisely because it encompasses so much of being human. No idea has endured so long, gathered up so many disparate needs and wants and feelings, and inspired so many different paths towards understanding it.

Surgeons always underestimate the pain and disability involved in what they do to people.

It's extraordinary to think that if you walked into a room and said you had never heard of Hamlet, you would be regarded as a Philistine. But you could walk into the same room and say, 'I don't know what a proton is,' and people would just laugh and say, 'Why should you know?'