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

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.'

Although religion might be useful in developing a solid moral framework - and enforcing it - we can quite easily develop moral intuitions without relying on religion.

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

It is time my colleagues got real. All British universities doing worthwhile research use animals, and, instead of hiding, they should be boasting of their achievements.

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.

We live longer and healthier lives than ever before. Animal research has improved the treatment of infections, helped with immunisation, improved cancer treatment and had a big impact on managing heart disease, brain disorders, arthritis and transplantation.