Question

In dogs, spotty fur is a recessive trait. Show a cross between two dogs that are heterozygous for spotty fur. What is the likelihood of these dogs having puppies with spotty fur?

Answer 1

Answer:

The correct answer is - 25% chances of having puppies with spotty fur.

Explanation:

In this question, it is given that spotty fur is a recessive character which means in the heterozygous condition it is not expressed in the phenotype. Here the cross between two heterozygous dogs for spotty fur will produce the following gametes:

Heterozygous: S and s where S is dominant allele and s is the allele for spotty fur that is recessive

Punnett square:

      S       s

S   SS     Ss

s     Ss     ss

By the Punnett square, we can say that likelihood of spotty fur (ss) in puppies is only 1/4 or 25%.