Hi

I am not sure if I am posting this in the correct area, but here it goes. I was told the other day that some males are only able to produce male sperm while other males are only able to produce female sperm? Which means some couples will only ever have boy babys while others will only have girl babys as when this occurs the male only had the ability to produce the one sex. Is this correct, I had always thought it was a 50/50 chance of getting either a baby boy or girl? Hope this makes sense.

Thanks
Jem