Answer:
Black dogs = A_B_
Brown dogs = aaB_
Yellow dogs = A_bb and aabb
Explanation:
In laborador retrievers, pigment color is influenced by two genes. Gene A determines the type of pigment produced and gene B affects whether the pigment gets deposited in the hair shaft. If two heterozygous black laborator retrievers were crossed and offspring were produced in a ratio of 9 black dogs to 3 brown dogs to 4 yellow dogs, what are the genotypes of the offspring?
Gene A determines colored pigment.
Gene B ensures that the colored pigment is deposited.
Two heterozygous black laborador retrievers were crossed.
AaBb x AaBb
Progeny
9 A_B_
3 A_bb
3 aaB_
1 aabb
Since there were 9 black, 3 brown and 4 yellow dogs, the possible genotype of the different colors are:
Black dogs = A_B_
Brown dogs = aaB_
Yellow dogs = A_bb and aabb