Question

Achondroplasia is an autosomal dominant condition and the homozygous dominant genotype is lethal. If Jason had a child with his current girlfriend, who is average height, set up a key for achondroplasia, determine the gametes and construct a Punnett Square showing the cross.

Answer 1

Okay so to fast get a overview of the situation we try to identify what genotype Jason and his girlfriend got.

Jason got Achondroplasia (non-lethal type) having a child with his girlfriend who does have Achondroplasia.
Lets assume that the dominant allele \(\bf A\) give Achondroplasia and the recessive allele \(\bf a\) regular height.

We should from here be able to conclude:
Jason: \(\bf Aa\)
Girlfriend: \(\bf aa\)

So to say we conclude that Jason is heterozygote with Achondroplasia in non-lethal form. In addition to that is his girlfriend homozygote recessive.

The Punnett square thereby become:


Try fill out the square and make some predictions about the possible outcome for their child.

Answer 2

Thank you so much! This really helps!!

Answer 3

Glad it does! If you want me to check your conclusions from the Punnett square square I'll be happy to.