What are dominant and recessive alleles with examples?

dominant alleles will always overrule recessive alleles. So if you have any dominant allele in the phnotype or geneotype, the dominant trait will be expressed. For example, since black fur is dominant to brown fur on mice, if two black mice mate, at least part of their offspring will have black fur. If they are heterozygous for black, though, that's when a brown mouse offspring may be possible, but there would always be more black offspring than brown offspring. parents offspring (4) Bb x Bb --> BB, Bb, Bb, bb BB x Bb --> BB, BB, Bb, Bb BB x BB --> BB, BB, BB, BB BB x bb --> Bb, Bb, Bb, Bb Bb x bb --> Bb, Bb, bb, bb anything with a capital B would be black while "bb" is the only brown.