Question: where do babies come from

Alice Jones Bartoli answered on 14 Jun 2011:

I’m going to assume you know all the how does sperm meet egg stuff that you learnt about in primary school, and get to the interesting stuff – the genetics of it all, or how do you get to be you.

So, the reason that you inherit characteristics from your mum and dad (and their mum and dad, and so on) is because of meiosis – a cell divides in half, giving that new cell only half of its original genetic material. This means that all of one man’s sperm is genetically different, and all of one woman’s eggs are also genetically different from each other. When a sperm and egg meet, the chromosomes carried by each of these (they’re called haploids) combine and a 46 chromosome cell is made – this is the beginning of the baby.