Question

Severe Combined Immunodeficiency (SCID) is a lethal (soon after birth) recessive genetic defect found primarily in Arabian horses. One study estimated that 6% of Arabian foals were affected by SCID, and that 42% were carriers of the recessive SCID allele.

a. Calculate allele frequencies for the normal and affected alleles at birth.

b. Since SCID is lethal, all affected individuals are eliminated from the population as foals (natural selection). What would be the genotypic frequencies (all of them) in the surviving population after the horses affected by SCID have died?

c. Calculate the allele frequencies in the surviving population.

d. If the surviving population then mates at random with respect to this gene (restoring HW eq), what is the expected frequency of affected horses in the next generation?

Type out and clearly label your work for full credit. The only math here is addition, multiplication, and division so it should be relatively easy to type.

Answer 1