This black dog has the genotype of BB for fur color. The black dog mates and has puppies with a solid white dog. The white dog has the genotype bb. What is the probability that this match will produce puppies that are also white?

Question

Responses
A 0%0%
B 25%25%
C 40%40%
D 50%50%

Answer 1

To determine the probability of the puppies being white from the mating of a black dog with the genotype BB (homozygous black) and a solid white dog with the genotype bb (homozygous white), we can use a simple Punnett square.

Here are the genotypes of the parents:

• Black dog: BB (can only contribute B alleles)
• White dog: bb (can only contribute b alleles)

When we set up the Punnett square:

         |   B   |   B
-------------------
     b   |  Bb   |  Bb
-------------------
     b   |  Bb   |  Bb

All offspring (puppies) from this combination will have the genotype Bb.

Since Bb (heterozygous) expresses the black fur color (dominant), none of the puppies will be white. Therefore, the probability of producing white puppies (genotype bb) is 0%.

The correct response is:

A: 0%