Question

In tomatoes, tall vine (T) is dominant to dwarf vine (t), and red fruit (R) is dominant to yellow fruit (r).

A gardener crosses a dihybrid tall tomato plant bearing red fruit with a true-breeding dwarf tomato plant with yellow fruit.

1. Describe the possible phenotypes and genotypes of the plants. Responses should include expected phenotype ratios. Explain your reasoning as needed.
2. If 100 of these tomato plant offspring were planted, how many plants would you predict you would find of each phenotype.


Please help

Answer 1

Possible genotypes: TtRr, Ttrr, ttRr, ttrr

Possible phenotypes: Tall with red fruit, tall with yellow fruit, dwarf with red fruit, darf with yellow fruit

Number of plants with the phenotype:

Tall with red fruit - 25 plants

Tall with yellow fruit - 25 plants

Dwarf with red fruit - 25 plants

Darf with yellow fruit - 25 plants

Step-by-step explanation:

To find the genotypes create a punnett square like the one in the image

To find the phenotypes examine the genotypes and detemine if they carry a dominant allele for the trait, if they have at least one dominant allele then the dominant trait that will be expressed, if they have two recessive alleles then the recessive trait will be expressed

To find how many plants that will have a phenotype if 100 plants were planted divide the number squares that have a particular phenotype from the punnett squares and divide that number by the number of total squares. Then multiply by 100

4÷16×100 = 25