Dominance

Question: Is dominance always dominant?

By doing the online lab activity, I have realized that alleles are not always completely dominant. There are three types of dominance. The first type is dominance. That is when one allele is completely dominant over the other, and that is where Mendel's hypothesis's can be considered true. An example of dominance would be the color of pea plants. There are two colors, purple and white. The purple is the dominant, while the white is the recessive allele. If both are homozygous, and are crossed, all of the offspring will be purple. The next type of dominance is co-dominance. That means that both of the alleles of a certain trait are expressed equally. An example of this would be the human blood types. If the mother has blood type A, and the father has blood type B, the children will have blood type AB, meaning that the both of the alleles are expressed. Finally, the last type is incomplete dominance. This means that one allele for a specific trait is not completely dominant over the other. An example of this would the snapdragon flowers. If red and white flowers were bred together, the offspring would end up being pink, meaning that both of the alleles "mixed" together, to create a completely new color of snapdragon.