In Yeast, There Are Three Gene Products Required to Synthesize

Multiple Choice

In yeast, there are three gene products required to synthesize the amino acid lysine. You cross two haploid lysine auxotrophs to form a diploid. The diploid fails to grow on plates lacking lysine. Which of the following can you conclude?

A) The haploid strains have mutations in the same gene.
B) The haploid strains have mutations in different genes.
C) The haploid strains form a complementation group.
D) The haploid strains do not complement each other.
E) Both (A) and (D) are true.