Giant squid aren't rare. Based on the number of beaks that have been found in the stomachs of sperm whales, it's thought that there are actually millions of them in the ocean, and yet, we haven't seen them.

Although each egg cell produced by a woman carries a single X chromosome, the sperm cells produced by a man carry either an X or a Y. This means, in very simple terms, that the sperm cell determines a baby's sex.

When we anthropomorphize the egg and sperm, when we turn them into a miniature bride and groom complete with personalities, what effect does this have on abortion legislation?

For my part, I would say that the male sperm and seeds of plants have been penetrated so far that there is nothing further to discover in this great secret, but I could err in my opinion.

Every batch of sperm represents an opportunity for genetic typos - called de novo mutations - to be passed on. A 20-year-old man and woman will each pass on about 20 de novo mutations to a baby they conceive. By the time the couple is 40, a woman's total has remained at 20, while a man's has jumped to 65 - and it keeps climbing from there.

I never thought a film about a sperm donor could work with audiences in India, but it did.

My dream is to have a baby, not to adopt one, because I am not up to it and I don't feel strong enough. I want my own child, a biological child, the fruit of my sperm, conceived through artificial insemination because it wouldn't make sense for me to make love to a woman I don't love.

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.

Just because you donate sperm does not make you a father. I don't have a father. I would never give him the credit or acknowledge him as my father.

Man comes not from an egg but from an animalcule that is found in male sperm.

Sperm is a bandit in its pure state.

In the seventeenth century, it was held by some that inside a human sperm there was a minute human being - a homunculus - that was planted inside the womb. Development consisted of the miniature homunculus enlarging and passing through birth and on to maturity-just like inflating a balloon.

People forget we come from an embryo and we're part sperm and part ovary. We have both sides in us.

A potential person is not a person, any more than an acorn is an oak tree. I don't think women should have to give birth just because a sperm met an egg.

Chance is hugely significant in biology. In fact, the presence of apparent randomness in so many aspects of biology - from mutations in DNA to the chance involved in that one sperm reaching that one egg that became you - suggests that randomness is useful, even necessary, in very many cases.

The cloning procedure is similar to IVF. The only difference is that the DNA of sperm and egg would be replaced by DNA from an adult cell. What law or principle - secular, humanist, or religious - says that one combination of genetic material in a flask is OK, but another is not?

For each chromosome contributed by the sperm there is a corresponding chromosome contributed by the egg, there are two chromosomes of each kind, which together constitute a pair.