No Connie, you are the one that cleared it up. Knowing that all this time when the reptile hobbyists have been saying codom and really meaning incdom changes the whole story, I was trying to get bio to fit into snakes rather than snakes into bio. Either way, genetics was hardly on the test, despite what my prof said the focus would be on....sooooo i screwed up everything on cell replication because I went to such great lengths to know the differences between all the genetic relationships, including pseudodominance which was covered in class....but incorrectly labeled as dominance. I am such a skeptic.

Anyway, thanks for the tips guys, and from now on codom=incomplete dom....if it is really a matter of not wanting to spell out incomplete dominance, call it incdom...it is one letter more than codom.

However, onto the debate.....incdom is present when the "Extra, typically 3rd" phenotype is a blending or "intermediate" of the other two, whereas in codom, the third phenotype is an expression of both of the other two equally. I dont particularly like this example but the blood type in humans is a good one.

There are 3 blood type genes, A, B and O. A and B are Codominant, whereas the O gene is recessive, and hence, more rare. So...A blood types are either AA or AO, B's are BB or BO, and O's have to be OO. Now, because A and B are codominant, AB's or BA's are considered AB blood type. In this type, both the A and B proteins are expressed in the blood.

To contrast this, if this example were considered incomplete dominance (just for teaching's sake, it is not incdom) then the A and B proteins would blend and form another blood type/protein completely, aside from the already recessive O. For example, instead of AB being Just A with Just B, it would be like if they melted together to form some new protein, X or Z, whatever you want to call it.

Another good, perhaps quicker example is with flowers

Codom---Red + White==Red and White spotted
Incdom---Red + White==Pink

Hope this clears it up at least a little, and if someone maybe wants to clear all this up, maybe the topic(not necesarily this thread) is sticky worthy?

Either way, thanks a lot to everyone that chipped in, or has been wondering about this too.


Ps--Another good answer Nancy, didnt get to read it since I was posting too. Thanks