Women of child-bearing age steadily run out of eggs by the continuous process of cell death. While reading a copy of the Guardian carefully from cover to cover, a normal woman will have lost on average two eggs - while, typically, a normal man will have made 70,000 new sperm.

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

You can now modify the genes of large animals, and the largest animal we are concerned with is the human.

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.

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.

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.

The disturbed individual who believes himself to be Christ, or to receive messages from God, is something of a cliche in our society. Ever since Sigmund Freud, many people have associated religiosity with neurosis and mental illness.