Question

Congenital analgesia is a rare autosomal recessive trait. What is the likelihood that the first two offspring of a cross between two unaffected parents heterozygous for the congenital analgesia trait will have congenital analgesia

Answer 1

The likelihood that the first two offspring of the cross will have congenital analgesia would be 1/16

Autosomal Recessive Traits

For autosomal recessive traits, two recessive alleles are needed for the trait to manifest while one recessive allele means heterozygosity.

In this case, let us assume that congenital analgesia is represented by the allele b; heterozygous individuals will, thus, be Bb.

            Bb    x    Bb

          BB   Bb   Bb   bb

Probability of producing unaffected offspring = 3/4

Probability of producing affected offspring = 1/4

Likelihood of the first two offspring having congenital analgesia = probability of first having congenital analgesia and the second having congenital analgesia

    = 1/4 x 1/4

        = 1/16

More on genetical probabilities can be found here: brainly.com/question/851793?referrer=searchResults