Question

The homozygous cc is normal, cc results in very long legs, and cc results in very short legs. the genotype bb produces black fur, bb brown fur, and bb white fur. assume the leg gene and fur colour gene described above are on different chromosomes. if a cross is made between brown rabbits with very long legs and white rabbits with very long legs, what percentage of the offspring would be expected to have very long legs and white fur?

a. 75%
b. 50%
c. 25%
d. 100%

Answer 1

Brown rabbits with very long legs crossed with white rabbits with very long legs will all have brown fur due to complete dominance of the brown allele; no offspring will be white. Therefore, 0% will have very long legs and white fur.

Step-by-step explanation:

When considering the cross between brown rabbits with very long legs (Cb nature) and white rabbits with very long legs (Cc nature), we must consider the genetics of fur color and leg length separately, as they are assumed to be on different chromosomes. Given that the fur color genes 'bb' result in brown fur, 'bb' result in white fur, and the phenotypic ratio for a heterozygous cross with two traits typically results in a 9:3:3:1 ratio, the outcome can be predicted. In this case, since we are dealing with a cross of organisms that are homozygous for long legs but different for fur color (bB x bb), all offspring will be heterozygous Bb for fur color, yielding 100% brown fur. As they are all heterozygous for the leg length gene (cC), which results in the very long legs, the percentage of offspring expected to have very long legs and white fur is 0% since all will have brown fur due to the complete dominance of brown over white.