Multiple alleles Transitional Reasoning Practice

Questions

1. 1.

   In a mammal species, coat color is determined by a single autosomal gene locus with four alleles exhibiting a complete dominance hierarchy: $C^1 > C^2 > C^3 > C^4$. A researcher crosses a male displaying the $C^2$ phenotype with a female displaying the $C^3$ phenotype, and exactly 25% of the resulting offspring express the $C^4$ phenotype. Which of the following statements correctly evaluates the genotypes of the parents and the expected phenotypic distribution of their offspring?

   • A) Both parents are homozygous for their respective visible traits, and 25% of their offspring will express the $C^1$ phenotype.
   • B) The male parent has the genotype $C^2C^3$, and 50% of the offspring are expected to express the $C^3$ phenotype.
   • C) The female parent has the genotype $C^3C^3$, resulting in equal 25% proportions for all four possible phenotypes.
   • D) Both parents are heterozygous carriers of the $C^4$ allele, and 50% of their total progeny are expected to express the $C^2$ phenotype.

Answers and step-by-step solutions appear after you finish the test.