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

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 do not know of any credible evidence that suggests Dr Zavos can clone a human being. This seems to be yet another one of his claims to get repeated publicity.

To build and strengthen new connections, the brain needs the challenge of fresh and unusual stimuli. .... There's a lot of evidence to suggest that repetition is bad for brain health, and novelty is good.

I'm a traditional Jew with an orthodox background, and it informs much of my approach to science. Of course I think it's very important that if you have those sorts of backgrounds you don't impose them on other people as a clinician, of course.

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

That Britain today is a liberal society is largely because of the philosophy and outlook of the Anglican Church, which did so much to shape our core values in the past few centuries.