Sperm are very different from all other cells
'There's a huge amount that we don't understand': Why sperm is still so mysterious 20 hours ago Share Save Katherine Latham Share Save How do sperm swim? How do they navigate? What is sperm made of? What does a World War Two codebreaker have to do with it all? The BBC untangles why we know so little about this mysterious cell. With every heartbeat, a man can produce around 1,000 sperm – and during intercourse, more than 50 million of the intrepid swimmers set out to fertilise an egg. Only a f