Animal rights activists talk about cruelty and torture, some backing their assertions by publishing out-of-date photographs of "experiments" banned long ago.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 know whether it is important to study science at a young age, though current thinking emphasises the need.

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.

Scientists need to be prepared to engage, and the best people to engage with are students, ideally from primary school because there's no question that their capacity to work out complex things is extremely good.

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

Carbon dioxide is unusual because it doesn't go through the usual three phases of matter, from solid to liquid to gas, but it goes straight from solid to gas. The volume of the gas is much greater than the volume of the solid. When a solid turns into a gas, we say it sublimes. The process is sublimation.

Medicine, which I wouldn't be without, has also been a force for... less good. For example, if you look at our mishandling of the immune system, using antibiotics in children and avoiding infection, we've certainly increased the risk of asthma.