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?'

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

We must not fail to recognise that television can be a hugely positive influence in children's lives, one of the greatest educators in contemporary society and an increasing influence on all the children followed in 'Child of Our Time.'

Following 25 children for the TV series 'Child of Our Time' has been extraordinary. The BBC's original plan was to commemorate the new millennium. What better way than to film a number of expectant mums from across the U.K.? Coming from widely different backgrounds, all were due to give birth on January 1, 2000.

Parents should talk to their children, even when they are babies and can't talk back.

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.'

My first vote was for a communist in east London when I was a medical student. But I've voted Tory, Labour and Lib Dem in my time.