Upon crossing BB with bb, we will get a hybrid of Bb.
Codominance is a phenomena in genetics where two alleles (different forms of the same gene) express themselves equally in an organism. As a result, characteristics linked to each allele are shown at the same time.
The MN blood group system in humans is an illustration of codominance. M and N alleles control the MN blood type. Red blood cells from people who are homozygous for the M allele carry a surface molecule known as the M antigen. On their red blood cells, those who are homozygous for the N allele contain the N antigen. A heterozygote is a person who carries both antigens.
(a) Genotype of blue scales fish will be BB.
(b) Genotype of blue scales fish will be bb.
(c) Genotype of blue scales fish will be Bb.
So, in this case B and b alleles will express equally.
