I think that good parenting should allow children to be children. That naivety and slightly open way of looking at the world is very valuable.

Animal rights activists talk about cruelty and torture, some backing their assertions by publishing out-of-date photographs of "experiments" banned long ago. This is a misrepresentation. The work we do is performed with compassion, care, humanity and humility. I have never seen an animal suffer pain.

I don't believe the fertilised egg can be equated with the sort of human life that you and I represent, or our children represent.

Now we have technology where we can modify the genomics of individuals by gene transfer and genetic meddling, we may find that people will want to modify their children, enhance their intelligence, their strength and their beauty and all the other so-called desirable characteristics.

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 like travelling on my own. It means I'm completely free to think about what's around me.

I did not study science at school until I was 13, when I was totally turned on by a seemingly dreary old teacher who suddenly, unannounced, manufactured a huge explosion in the middle of a totally boring monologue. From then on, all of his class wanted to make explosions.