In garden peas,one pair of alleles controls the height of the plant,and a second pair of alleles controls flower color.The allele for tall (D)is dominant to the allele for dwarf (d),and the allele for purple (P)is dominant to the allele for white (p).A tall plant with white flowers crossed with a dwarf plant with purple flowers produces 1/4 tall purple,1/4 tall white,1/4 dwarf purple,and 1/4 dwarf white.What is the genotype of the parents?
A) Dd Pp x Dd pp
B) Dd Pp x Dd Pp
C) DD Pp x dd Pp
D) Dd pp x dd Pp
E) DD Pp x dd pp

Question

In garden peas,one pair of alleles controls the height of the plant,and a second pair of alleles controls flower color.The allele for tall (D)is dominant to the allele for dwarf (d),and the allele for purple (P)is dominant to the allele for white (p).A tall plant with white flowers crossed with a dwarf plant with purple flowers produces 1/4 tall purple,1/4 tall white,1/4 dwarf purple,and 1/4 dwarf white.What is the genotype of the parents?  
A) Dd Pp x Dd pp
B) Dd Pp x Dd Pp
C) DD Pp x dd Pp
D) Dd pp x dd Pp
E) DD Pp x dd pp

Quizplus · Accepted Answer

The ratio of the offspring suggests that both traits are segregating independently in a dihybrid cross. Using the Punnett square, we can deduce that the genotype of the tall plant with white flowers is Dd pp (since all offspring have a dwarf phenotype and the dwarf parent is homozygous recessive for height). The genotype of the dwarf plant with purple flowers is dd Pp (since all offspring have a purple flower color and the tall parent is heterozygous for flower color). Therefore, the best choice is Dd pp x dd Pp.

In Garden Peas,one Pair of Alleles Controls the Height of the Plant,and