Question

If G=yellow seeds and g=green seeds, a) predict the genotypic and phenotypic ratios of a cross between a heterozygote and a homozygous recessive individual. b) show the genotypic and phenotypic ratios of the F2 of a cross between a gg and GG individual.

Answer 1

Answer:

a) Genotype ratio= 1/2 Gg: 1/2 gg

Phenotype ratio = 1/2 yellow seeds: 1/2 green seeds

b) Genotype ratio= 1/4 GG : 1/2 Gg: 1/4 gg

Phenotype ratio= 3/4 yellow seeds : 1/4 green seeds

Explanation:

a) Genotype of heterozygote parent plant = Gg

Genotype of homozygous recessive parent plant= gg

A cross between Gg x gg gives progeny in following ratio= 1/2 Gg (yellow seeds) : 1/2 gg (green seeds)

b) Parent plants = GG x gg

F1= Gg

A cross between Gg x Gg would give F2 progeny in following ratio= 1/4 GG (yellow seeds): 1/2 Gg (yellow seeds) : 1/4 (green seeds)