Multiple alleles/Polygenic Traits


Multiple Alleles: Genes that have more then two alleles
Polygentic Traits: Traits controlled by two or more genes.
Allele: one number of different forms of a gene

Textbook page 273; Multiple Alleles determine a rabbits coat color. Coat color is determined by one gene, but within that gene there are four different alleles. These alleles show patterns of simple dominance in a punnent square will display all the different gene combinations.

Textbook page 273; Polygenetic Trait. Example: skin type of humans has four genes involved and that is why there is such a wide varity of human skin types.

Sample Problem for a Multiple Allele: What would be the parents of the following offspring?

1. A blood type-Dominant
B blood type -Dominant
O blood type- Recessive

Answer:
25% AB Blood-type
25% Heterozygous B Blood-type
25% Heterozygous A Blood-type
25% Pure O Blood-type

Link to Eye-Color Calculator: http://www.athro.com/evo/inherit.html (Polygentic Traits)