Editing Phenotypic trait (section)

==Biochemistry of dominance and extensions to expression of traits==
The [[biochemistry]] of the intermediate proteins determines how they interact in the cell. Therefore, biochemistry [[philosophy of science|predicts]] how different combinations of alleles will produce varying traits.{{citation needed|date=March 2023}}

Extended expression patterns seen in diploid organisms include facets of [[incomplete dominance]], [[codominance]], and [[multiple alleles]]. Incomplete dominance is the condition in which neither allele dominates the other in one heterozygote. Instead the phenotype is intermediate in heterozygotes. Thus you can tell that each allele is present in the heterozygote.<ref>{{cite web|last=Bailey|first=Regina|title=What is incomplete dominance|url=http://biology.about.com/b/2007/09/29/what-is-incomplete-dominance.htm|publisher=About.com}}</ref> Codominance refers to the allelic relationship that occurs when two alleles are both expressed in the heterozygote, and both phenotypes are seen simultaneously.<ref>{{cite web|last=McClean|first=Philip|title=Variations to Mendel's First Law of Genetics|url=http://www.ndsu.edu/pubweb/~mcclean/plsc431/mendel/mendel2.htm}}</ref> Multiple alleles refers to the situation when there are more than 2 common alleles of a particular gene. Blood groups in humans is a classic example. The [[ABO blood group system|ABO blood group]] proteins are important in
determining blood type in humans, and this is determined by different alleles of the one locus.<ref>{{cite web|last=Unknown|title=Multiple Alleles|url=http://www.occc.edu/biologylabs/Documents/Tutorial_Genetics/Multiple_alleles.htm}}</ref>