That's just a 6% chance of any "defect" continuing through each generation.
This figure is assuming a uniform distribution of all genetypes
according to genetics if both parents have the same thing i think it's a 50/50 chance of your child having your disease
unless i read that part of the book wrong
It might depend on whether the gene for the disability is recessive or dominant (if it's controlled by one gene).
It's a lot more complicated than this. By looking at someone you can determine whether or not they possess the trait (phenotype) but since an organism's DNA is composed of two copies, there are three different genetic variations (genotypes). Crossing two parents with three different possibilities results in six different possible pairs
I don't feel like drawing or typing up fancy punnet squares so just have this:
AA x AA = 100% AA
AA x Aa= 50% AA, 50% Aa
AA x aa = 100% Aa
Aa x Aa= 25% AA, 50% Aa, 25% aa
Aa x aa = 50% Aa, 50% aa
aa x aa = 100% aa
aa results in the recessive phenotype, whereas AA or Aa result in the dominat phenotype.
If possession of a trait is recessive, then yes, two parents with the trait will breed 100% of offspring with the trait.
But if the trait is dominant, it's much more complicated than that.
Of course, this is even further complicated by traits linked to more than one traits, traits where heterozygous and homozygous dominant give slightly different results, epigenetics, and probably a few other things. It's also not including the fact that there are plenty of disorders that aren't genetic related at all, or where genetics only gives a predisposition
if the problem is bad enough then you won't get laid
This. There's no need to "prevent" them from doing it. It'll be handled by itself; it's called natural selection. No one (or at lest, very few people) are going to want to date/forget someone where's very badly disabled. And there's nothing wrong with it, it's their natural instincts telling them "this person will not be a good care giver and provider for my children" which is, biologically/evolutionarily the sole purpose for dating/love