A haploid yeast strain has mating type a and genotype his4 TRP1. A different haploid yeast strain has mating type ? and genotype HIS4 trp1. The two strains mate and produce diploid offspring with genotype his4 TRP1 / HIS4 trp1. The diploid cells undergo meiosis to produce a variety of tetrad types. In the following questions, the genotypes of the spores in a tetrad are shown. For each tetrad, tell what type it is: parental (PD), non-parental (NPD), or tetratype (T).
-his4 TRP1; his4 TRP1; HIS4 trp1; HIS4 trp1
A)PD
B)NPD
C)T
D)cannot be determined

Question

Quizplus · Accepted Answer

Parental ditypes (PD) consist of spores that have the same genotype as the original parents. In this case, the tetrad shows two spores with the genotype of one parent (his4 TRP1) and two spores with the genotype of the other parent (HIS4 trp1), which is characteristic of PD.

A Haploid Yeast Strain Has Mating Type a and Genotype