Question

A gardener crosses a true-breeding tall tomato plant bearing red fruit with a true-breeding dwarf tomato plant with yellow fruit. In tomatoes, tall vine (T) is dominant to dwarf vine (t) and red fruit (R) is dominant to yellow fruit (r).
Predict the phenotypes and genotypes of the F1 generation.

Answer 1

Cross of true breeding dominant and recessive tomato plants will have:

Phenotype ratio in F1 generation is 4:0

genotype ratio in F1 generation is 4:0.

Explanation:

Data given:

Tall vine = dominant TT

dwarf vine = recessive tt

red fruit dominant  RR

yellow fruit recessive   rr

true breeding tall tomato plant bearing red fruit is TTRR

true breeding dwarf tomato plant bearing yellow fruit = ttrr

the cross is shown in punnet square:

      TR       TR

tr    TtRr    TtRr

tr  TtRr    TtRr

the phenotype ratio- 4:0

the genotype ratio - 4:0

The phenotype is tall vine with red fruit

Genotype is all the progeny are heterozygous dominant.