Friday, September 10, 2010 9:27:59 AM
For the handful of people saying it should be a 50/50 split, chew on this: a spermatozoa carrying a Y-Chromosome has less mass than one carrying an X-Chromosome. This means the Y can travel faster than an X, therefore having a better chance of reaching the egg first.
Thursday, September 9, 2010 10:28:55 AM
the Y chromosomes are weaker so like theBenighted said, damage and even heat from wearing tight underwear/trousers can kill them off and leaves the X