Did you know?
Did you know that the color of a bear's fur is determined by the interaction of dominant and recessive alleles? In bears, the dominant allele (F) produces brown fur, while the recessive allele (f) results in white fur. When a heterozygous male bear (Ff) is crossed with a homozygous recessive female (ff), the probability of certain combinations of offspring can be predicted.
a. In the case of a litter of six cubs all with white fur, the probability would be 100%. This is because the homozygous recessive female (ff) can only contribute the recessive allele (f) to each offspring, and the heterozygous male (Ff) can pass either the dominant allele (F) or the recessive allele (f) to each cub. However, since the recessive allele (f) is necessary for white fur, all the cubs would inherit the recessive allele (f) from their mother and have white fur.
b. For a litter of five cubs, two with brown fur and three with white fur, the probability calculations involve more complexity. Each offspring has a 50% chance of inheriting the dominant allele (F) from the heterozygous male, resulting in brown fur. Moreover, since the female is homozygous recessive (ff) and can only pass the recessive allele (f), each offspring has a 50% chance of inheriting the recessive allele (f) from the mother.
To calculate the probability of two cubs having brown fur, the probability of each event is multiplied together. Therefore, the probability of one cub having brown fur would be 0.5 (from inheriting the dominant allele from the male) multiplied by 0.5 (from inheriting the recessive allele from the female), resulting in 0.25 or 25%. To determine the probability of two cubs having brown fur, we multiply 0.25 by 0.25, resulting in 0.0625 or 6.25%.
For the remaining three cubs to have white fur, they must inherit the recessive allele (f) from both the male and female. Since each offspring has a 50% chance of inheriting the recessive allele (f) from the mother, the probability of one cub having white fur would be 0.5. Therefore, to calculate the probability of three cubs having white fur, we multiply 0.5 by 0.5 three times, resulting in 0.125 or 12.5%.
In summary, the probability of having a litter of five cubs, two with brown fur and three with white fur, would be 6.25% for the brown fur combination and 12.5% for the white fur combination.
