In some cases there are Dominant alleles. If this were the case the cat would only show one trait, in this case, black or orange fur. So it can't be that.
Another option would have been Incomplete Dominance. In that situation the cat would have been a mixed between the orange and black color.
(For example; say you have a red flower and a flower. If the offspring were pink, that would be <em>incomplete dominance.</em>
So it also can't be this option.
In the case of a Recessive allele there would have only been one color.
In order for a recessive allele to become manifested that trait from both of the alleles(one from each parent) would have to be recessive. If not the dominant allele would always be the one to show through.
This leaves us with the option of Codominance. Codominance is when one allele doesn't show over the other one(<em>Dominant alleles)</em> or when the two don't mix to make a new allele(<em>Incomplete Dominance) </em>and both traits from each parents show up on the offspring.
(For example; a white cow and a brown cow produce offspring brown and white fur.)
So because the cat has both traits for black <em>and</em> orange fur this would be a form of codominant allele expression.
