Special Genetics & Pedigrees

In the class before our test, we reviewed some types of special genetics, and we learned about a pedigree. The special genetics that we learned included Codominance, Incomplete Dominiance, and X-linked.

Codominance

Both colors are shown in the F1 generation. Not just one color, and not a mix of the colors. This is because both the gene for red color and the gene for white color are dominant.

People with type AB blood are dominant for both A and B.

The fish shows both colors.

So does the cow.

Incomplete Dominance

The F1 generation is a mix between the two parents. Red x White = Pink. 

Color dominance is incomplete.

White Dog x Brown Dog = Gold Dog

X-linked

Gene is attached to chromosome. Men cannot be heterozygous, the gene is not present on the Y chromosome. Women can be carriers, so have a slimmer chance of actually showing the recessive trait.

Pedigree

Shows the family tree for the trait. Can be a X-linked trait or autosomal. Don't be tricked by Mr. Quick into drawing one of these for no reason. He is sneaky!