Some coworkers and I had a friendly argument yesterday about the DNA in a human ovum. I had always thought that each of a woman’s ova contained the same DNA, and that there was some random aspect to the way it combined with the sperm’s DNA, thus accounting for variation among children. In other words, if two people have multiple children, it’s the same DNA combining each time, but it combines differently.
My coworkers were of the view that each of a woman’s ova contained different DNA, so that children are destined to be different even before fertilization. (I recognize that in my scenario, children are almost certainly going to have different DNA anyway; the question is when the variation arises).
Does anyone know how this works? Also, if you happen to have a link, it would help to settle the argument.