For adults, the most common sources of food allergic reactions are: 1  shellfish (that includes shrimp, lobsters, and crabs) 2  nuts from trees (such as walnuts) 3  fish. 4  eggs. more information...
When binary traits are available, they become classified as Dominant or recessive. A dominant trait is a trait the is evident by the appearance of the organism. A recessive trait is a trait the is present but is not evident in the appearance of the organism. Dark hair is a dominant trait to a recessive light hair trait. Two brunettes may have a chance of having a blonde child due to the fact that either of them may carry the blonde haired gene and not show it.
The genes for these traits are on the autosomes. Dominant does not mean prevalent, dominant traits can be rare (achondroplasia, TNR, NF1, etc.). Dominant means you need only one mutant gene to express the trait. In general, the heterozygote and homozygote for the mutation show the same phenotype.