Explain what is incomplete dominance?

1 Answer
Jun 6, 2018

The heterozygous genotype is blended

Explanation:

Okay so let's say the dominant trait is Red. So the allele is R.
Then let's say the recessive trait is blue, r.

With normal dominance
RR is RED RED. You get a big old red flower
rr is blue blue. You get a blue flower.
Rr is Red blue. And as it happens, with normal dominance, the stronger allele here, red, means that the the flower will carry one blue allele but will look red.

With incomplete dominance , while the RR is still red and the rr is still blue, the Rr is not red. It's purple, a blend or red and blue together.

Normally you've learned that the dominant allele is strong enough to mask the recessive allele completely, so no matter the genotype the phenotype will be that of the dominant if the dominant is in there. Here either the recessive (r) isn't that weak compared to the Dominant so a little bit of both come through!