Simple dominance, known as "complete dominance" is when oneallele is expressed over another (the recessive gene is notexpressed at all).Two other patterns are incomplete dominance and codominance.Incomplete dominance is when a trait is expressed that issomewhere inbetween the two alleles. For example, if BB is blackfur and bb is white fur, Bb would be grey fur.Codominance is when both traits are expressed. For example, ifRR is red and rr is white, Rr would be white with red spots (or redwith white spots).