what is the difference between codominance & dominance?

Answer 1

When one of the two alleles of a trait appears and the other partner remains passive, the allele which is expressed is called a dominant allele against the one which is not expressed. The one that is not expressed in the presence of its counterpart is called the recessive allele.
In case of codominance both the alleles are expressed. Neither is recessive.
The best example of codominance is AB group of blood. In this a person having allele for A and B antigens are both expressed.
The case of incomplete dominance is different. Here the heterozygote for a trait produces an intermediate phenotype. A red and white colour allele together may give rise to pink form.

Answer 2

Dominance refers to simple dominance like Mendel was talking about. It means that the dominant form of the trait shows and the recessive doesn't show at all when an individual has both forms of the gene. So if tall peas are dominant to short, then a Tt plant is tall.

Codominance means that both forms of the gene are fully expressed -- both show up at the same time. An example of this is coat color in cattle or horses where RR is red and WW is white. One that is RW has red hairs and white hairs and is called roan. Another example is the codominance of A and B in blood type -- someone with both alleles is Type AB.

Answer 3

In codominance, two genes are displayed. For example, if a purple and white flower made offspring and the offspring got the purple gene and white gene then it would be pink. If it was dominance, and the purple gene was the dominant trait, then the flower would be purple, not a cross between both.

Answer 4

Dominance is when one trait rules over another - Like the color of fur, white or black. It's either white or it's black. That's it.

Codominance is when the two traits are both expressed - for example, the black and white fur would blend together to form gray.