Recessive Blood Group O
Country: United States
Date: Winter 2009 - 2010
If O type blood is the oldest, why is it recessive?
The gene for type A and B antigens code for antigens which appear on
the red blood cell. The gene for type O antigen does not code for an
antigen. If you carry one of each, type O and type A for example, then
your red blood cells will carry the type A antigen.
Ron Baker, Ph.D.
One of the biggest misconceptions in genetics is the incorrect idea
that recessive genes are weak. The word recessive gives that idea,
but in reality, and in this case, the Type O gene really means that
there is no protein being produced. Type O means zero or nothing in a
sense. Type A and B are labels given to types of blood group
proteins. If you have the alleles O and A (one from each parent), you
will have type A blood because the A protein is present and the O (no
protein) means A is seen. Hence, in this case, the label of "recessive". Type O is
called recessive only because nothing is there.
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Update: June 2012