[Thanxyall]

For biologyThanks

[jonmcn49]

They are not masked, not carried, and so deleteriously exposed and selected against.Also, many are late onset. Coming on after the organism has reproduced.

[Lea]

Dominant genetic disorders are more rare because they will never be hidden or even toned down by the presence of one"normal"allele for a gene. They are also often more extremely expressed and therefore those that have these disorders often do not reproduce and therefore the trait is often not passed on. recessive diorders on the other hand are often partially masked and may not become obvious until after reproductive age. This means that people will often have children and pass on the trait before even knowing that they have it. This means that the trait will remain present in the population and therefore have a greater chance of being expressed.