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Autosomal Dominant Traits

The four characteristics of autosomal dominant traits are: Affected people have an affected parent, affected people have a 50% chance of passing the trait onto offspring, males and females are equally likely to be affected, and dominant traits are usually seen in multiple successful generations.

These four characteristics make perfect sense, and can be easily explained with a simple knowledge in genetics. Autosomal refers to 22 chromosome pairs, every person has 23 including their sex chromosome. This means that no matter the gender of a person they can carry an autosomal dominant trait. The remaining characteristics can be explained by demonstrating a simple Punnett square.

Carrier parents B b
B BB Bb
b Bb bb

 

Carrier and Affected Parents B b
B BB Bb
B BB Bb

 

As shown above carrier parents have a 50% chance of have a child that is a carrier and a 25% chance of having an affected child. Parents where one is affected and the other is not have a 50% chance of having a carrier child, and a 50% chance of having an affected child. This brings me to the first characteristic listed: Affected people have an affected parent. Since this is a dominant trait the dominant trait will always mask the recessive. Because of the dominant trait masking the recessive the trait will most likely be continued to pass down.

In the Dragon Genetics Lab a list of dominant and recessive traits indicates that having no fangs is a dominant trait, and having fangs is a recessive trait. Since dragons are carnivorous having fangs is extremely important in order to survive, and most of the dragon population has fangs. However, even if there is a homozygous recessive dragon (dragon with fangs) and a heterozygous recessive dragon (dragon with no fangs) there is a 75% chance of having an offspring that does not have fangs, a devastating disadvantage.

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