Question

In a particular species of flower, tall is dominant to short. Orange petals are dominant to the recessive white color. Using T/t to symbolize the alleles for height, and F/f to symbolize the alleles for flower color. A homozygous tall, white flowering plant is crossed with a flower heterozygous for both traits. List the genotypes of the parents. What are the F1 genotypic and phentypic ratios

Answer 1

Answer:

Explanation:

The parents phenotypes are

TTff x TtFf

The f1 genotype will be

TTFf, TTff, TtFf, Ttff

The phenotypic ratio of tall and orange colored is 4/8= ½

The phenotypic ratio for tall and white is 4/8= ½

The genotypic ratio for each is ¼

Answer 2

Answer: The parents phenotypes are TTff for a homozygous tall white flowering plant and TtFf for a plant heterozygous for both traits.

The genotypic ratio of the F1 offsprings is 4TTFf : 4TTff : 4TtFf : 4Ttff.

The phenotypic ratio of the F1 offsprings is 8 tall and orange flowering plants : 8 tall and white flowering plants.

Explanation: From the information provided, T is dominant to t while F is dominant to f. A plant that is homozygous for both tall and white flower will have two identical alleles for each trait, therefore its genotype will be TTff. A plant that is heterozygous for both traits will have one dominant allele and one recessive allele for each trait. Therefore its genotype will be TtFf.

A dibybrid cross between the two plants: TTff x TtFf will produce 16 offsprings with four possible genotypes: TTFf, TTff, TtFf and Ttff.

Out of the 16 offsprings, 4 are TTFf, 4 are TTff, 4 are TtFf and 4 are Ttff. Therefore, the genotypic ratio is 4TTFf : 4TTff : 4TtFf : 4Ttff.

TTFf and TtFf will manifest outwardly as tall and orange flowered while TTff and Ttff will manifest outwardly as tall and white flowered, therefore the phenotypic ratio is 8 tall and orange flowered plants : 8 tall and white flowered plants.

See the punnett square attached