Ok, I get that when a gene has a dominant mode of inheritance that you only need 1 copy to express that trait, and the fact that it is autosomal means that it is not sex linked. However, I am confused about how we figure the probability of passing these traits to offspring. Say, for instance, that a male is carrying the gene for polycystic kidney disease, which is an autosomal dominant trait. If he has a son, the son has a 50% chance of inheriting the disease? They say its 50%, but this is assuming that the father has only 1 dominant allele, well call it P, for this trait, as opposed to both allele. So, if the father were Pp, and the mother carried the normal allele, the offspring would have a 50% chance of having the disease? and if the father were PP, then ALL of the offspring would have this disease? So basically, for autosomal dominant traits, the chance that offspring carry that trait depends on whether the parent carrying the alleles has 2 copies of the dominant allele or 1 copy of the dominant allele? is this correct?