Biology/Codominant vs. Incompletely dominant alleles of a gene
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Question
Is there a such thing as a trait that is not dominant but not recessive? Would this person be considered a carrier?
Dear Whitney,
There are some alleles of genes that are neither dominant nor recessive. These can be codominant or incompletely dominant--and there is a subtle difference between them.
You can read more about this type of inheritance here:
http://www.hobart.k12.in.us/jkousen/Biology/inccodom.htm
An individual whose genome contains codominant or incompletely dominant alleles of a gene isn't truly a "carrier", since a carrier is generally considered to be an individual whose genome contains a particular allele that is not expressed at all. In the case of codominance or incomplete dominance, both alleles of the gene are expressed to some degree.
Hope that helps.
Dana
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Answers by Expert:
Dana Krempels, Ph.D.
Expertise
I can answer biology-related questions in the areas of evolution, zoology, botany, genetics, and ecology. But I don't answer homework questions or provide ideas for your science fair projects. So students please do your learning the right way by reading your text assignments and studying!
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At the University of Miami, I teach Evolution and Biodiversity, Botany, Zoology, Genetics, Ecology, and a variety of seminars (e.g., the Biology and Evolution of Human Gender Roles).
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I have a B.S. in Biology and an A.B. in English from the University of Southern California (1980).
I earned my Ph.D. in Biology in the area of evolutionary biology/visual physiology from the University of Miami in 1989.
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I am currently an "expert" in both the "Rabbits" and "Wild Animals" categories.
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