Imagine that we mate two black Labrador dogs with normal vision and find that three of the puppies are like the parents, but one puppy is chocolate with normal vision and another is black with PRA (progressive retinal atrophy, a serious disease of vision). We can conclude that
A) both of the parents are homozygous for both traits.
B) the same alleles that control coat color can also cause PRA.
C) the alleles for color and vision segregate independently during gamete formation.
D) the alleles for color and vision segregate dependently during gamete formation.

Question

Quizplus · Accepted Answer

The fact that the puppies have different coat colors and vision status suggests that the alleles for color and vision segregate independently during gamete formation. This indicates that the traits are controlled by genes located on different chromosomes, which assort independently during meiosis. Option A is unlikely since both parents produced puppies with different coat colors and vision statuses. Option B is not supported by the information given as there is no known link between coat color and PRA. Option D is incorrect as it implies that the segregation of color and vision alleles is dependent on each other, which is not supported by the observed results.

Imagine That We Mate Two Black Labrador Dogs with Normal