Codominance vs. Incomplete Dominance

[2th Doc]

So on pg. 94 of Cliff's AP Bio 3rd edition, it says incomplete dominance of alleles can make an intermediate allele, like make pink from red and white in flowers.

Then for Codominance it says that both alleles are shown.

However, on pg. 100 question 10, it says that the codominant alleles R (red) and R' (white) make pink flowers. Wouldn't codominance in this way make red/white flowers, like spotted or some other pattern? I guess since it specifically states that RR' make pink flowers in the question then you can assume it's right as far as choosing which answer is correct, but codominance wouldn't typically blend alleles like in incomplete dominance would it?

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[ll REVOFEV ll]

From what I understand, incomplete dominance is a mix of the phenotypes, like you said, so red and white would make pink. Also, codominance would make splotchy flowers. So in the case that you were crossing a purple and a white flower it would have white and purple spots on it. So yup I think you are understanding it correctly...but that question is just a little weird.

 

[woox]

OMG we are on the same page!

Its easier to think of codominance as blood type like AB blood is IA IB, both dominant, both are expressed.

And it depends on what problem says...usually anything blending = incomplete dominance

 

[yappy]

Another way to think of codomanace is blood types. If AB antigens are being fullexpressed the alleles are codomenent.

Yes, incomplete is a blend of the two.

 

[2th Doc]

Okay, well it seems like we're all on the same page... Cliffs just decided to put their own false statement into the question to see if we can read and comply or something... either that or that example is an exception... or a poorly written question overall. Who knows. Thanks for the replies.