Answer:
Let us assume the alleles responsible for coat color be B and b.
B is dominant over b and codes for black coat color whereas b codes for red coat color in homozygous recessive condition.
So, hetrozygous black bull would be having Bb genotype and red cow would be having bb as their genotype.
Gametes formed by black bull = B and b
Gametes formed by red cow = b and b
Offspring = 2 Bb and 2 bb i.e. 2 black and 2 red.
Hence, phenotypic ratio (black : red)= 2 : 2 = 1 : 1, and
genotypic ratio (Bb : bb)= 2 : 2 = 1 : 1
