If Mendel did not know the genotype of a pea plant with yell

If Mendel did not know the genotype of a pea plant with yellow pods (Y?), what genotype should he cross the unknown with in order to determine its genotype for pod color? (Hint: the offspring of this cross would have the highest probability of displaying all possible phenotypes).

a) Yy

b) YY

c) yy

Solution

c). yy\'

To determine the unknown genotype of a plant, test cross is performed using the homozygous recessive genotype.

Test cross is done to determine the genotype (weather homozygous or heterozygous) of the individual in question mark. If the cross between the dominant trait and recessive individual results in both dominant and recessive phenotypes (in 1:1 ratio) in the offspring, the individual in question mark is “heterozygous.” If all the offspring are of dominant type, then the individual in question mark is “homozygous dominant.”