Question

The observed numbers for dominant and recessive types in an F2 generation are 154 and 46. What would the expected number of individuals with a heterozygous genotype?

Answer 1

Answer: Expected heterozygous genotype = 2×46 = 92

Explanation:

According to the hypothesis of segregation of paired genes in heterozygous F1 generation crosses produces 1:2:1 genotype ratio. This means that all these three possible genotypes should be produced in the F2 generation meaning that we have 1(Dominant homozygous) :2 (Dominant heterozygous): 1 (Recessive Homozygous).

Phenotypic ratio shared (dominant: recessive) = 154 and 46

If recessive homozygous phenotype = recessive homozygous genotype = 46

The expected dominant heterozygous genotype= 2 × (recessive homozygous genotype)

= 2 × 46 = 92