Final answer:
The genotypes of the offspring in cattle when both b and w alleles are present can be determined using a Punnett square. The genotypes would include BB, Bw, wB, and ww. This results in a ratio of 25% white, 50% roan, and 25% red offspring.
Step-by-step explanation:
In cattle, the genotype bw represents a heterozygous individual with roan fur. The gene for coat color in cattle is represented by the alleles b (white) and w (red). In this case, the allele b is codominant with w, which means that both alleles are expressed in the offspring. Therefore, when a heterozygous bw individual is crossed with another heterozygous bw individual, the genotypes of the offspring can be determined using a Punnett square.
A Punnett square is a diagram that helps determine the possible genotypes and phenotypes of offspring in a genetic cross. For this cross, the Punnett square would show that there are four possible genotypes: BB (white), Bw (roan), wB (roan), and ww (red).
Therefore, the genotypes of the offspring would be BB, Bw, wB, and ww. This means that 25% of the offspring would be white, 50% would be roan, and 25% would be red.