Question

In cocker spaniels, solid coat color is dominant over spotted coat color. Suppose a homozygous solid-colored dog is crossed to a spotted dog and the F1 are crossed with each other. If three F2 puppies are born, what is the probability that at least one of the three puppies will have a spotted coat

Answer 1

Answer:

0.5781

Step-by-step explanation:

Let 'S' be the dominant allele for solid coat color and 's' be the recessive allele for spotted coat color.

By crossing a homozygous solid-colored dog (SS) with a spotted dog (ss), all of the F1 will present the Ss genotype.

When crossing two F1 dogs, the sample space for F2 is:

F2={Ss,sS,ss,SS}

For each puppy, there is a 1 in 4 chance of having a spotted coat.

The probability that at least one of the three F2 puppies have a spotted coat is 100% minus the probability that none have a spotted coat:

$P(ss>0) =1- P(ss=0)\\P(ss>0) =1- (1-\frac{1}{4} )^3\\P(ss>0) = 0.5781$

The probability that at least one of the three F2 puppies will have a spotted coat is 0.5781.